Tuberculosis Control and Socio-economic factors

World Tuberculosis Day, falling on 24 March each year, is designed to build public awareness that tuberculosis today remains an epidemic in much of the world, causing the deaths of several million people each year, mostly in the third world. 24 March commemorates the day in 1882 when Dr Robert Koch astounded the scientific community by announcing that he had discovered the cause of tuberculosis, the TB bacillus. At the time of Koch's announcement in Berlin, TB was raging through Europe and the Americas, causing the death of one out of every seven people. Koch's discovery opened the way toward diagnosing and curing tuberculosis.

Tuberculosis
Tuberculosis is a disease that is spread from person-to-person through the air. It is caused by Mycobacterium tuberculosis, a slowly growing bacterium that is resistant to most antibiotics and, thus, difficult to treat. Despite the availability of effective therapy since the 1950’s, there are more cases of tuberculosis in the world today than in recorded history.
Left untreated, tuberculosis can kill approximately one half of patients within five years and produce significant morbidity (illness) in others. It is estimated that one-third of all HIV-infected patients die from tuberculosis and that it kills more adults than any other infectious disease. Inadequate therapy for tuberculosis can lead to drug-resistant strains of M. tuberculosis that are even more difficult to treat; the drugs needed to treat these strains are associated with more drug toxicities and greatly increased costs.


WHO report 2009 - Global tuberculosis control
Although the total number of incident[new] cases of TB is increasing in absolute terms as a result of population growth, the number of cases per capita is falling. The rate of decline is slow, at less than 1% per year. Globally, rates peaked at 142 cases per 100 000 population in 2004. In 2007, there were an estimated 137 incident cases per 100 000 population. Incidence rates are falling in five of the six WHO regions. There were an estimated 13.7 million persons suffering from TB in 2007 (206 per 100 000 population), a decrease from 13.9 million cases (210 per 100 000 population) in 2006.
An estimated 1.3 million deaths occurred among HIV-negative incident cases of TB (20 per 100 000 population) in 2007. There were an additional 456 000 deaths among incident TB cases who were HIV-positive.


There were an estimated 0.5 million cases of multidrug-resistant TB (MDR-TB) in 2007. There are 27 countries (of which 15 are in the European Region) that account for 85% of all such cases. The countries that rank first to fifth in terms of total numbers of MDR-TB cases are India (131 000), China (112 000), the Russian Federation (43 000), South Africa (16 000) and Bangladesh (15 000). By the end of 2008, 55 countries and territories had reported at least one case of extensively drug-resistant TB (XDR-TB).


Multi-drug resistant tuberculosis (MDR-TB)
Multi-drug resistant tuberculosis (MDR-TB) is defined as TB that is resistant at least to isoniazid (INH) and rifampicin (RMP). Isolates that are multiply-resistant to any other combination of anti-TB drugs but not to INH and RMP are not classed as MDR-TB.
MDR-TB mostly develop in the course of the treatment of fully sensitive TB and this is the result of patients missing doses, doctors giving inappropriate treatment, or patients failing to complete a course of treatment.Once drug-resistant tuberculosis is created it can then be spread to other susceptible individuals. HIV-infected patients have helped to amplify the global drug resistance problem because HIV-infected patients with tuberculosis are more likely to acquire drug resistant tuberculosis (particularly rifampin-resistant) and are more likely to develop tuberculosis once infected.
Despite the availability of effective treatment regimens there are more drug-resistant cases of tuberculosis today than at any time in history. Ineffective tuberculosis control programs in resource poor areas have contributed to the spread of the disease.


XDR-TB
The world is also concerned now about XDR-TB or eXtensively Drug Resistant TB, a subset of MDR-TB also resistant to fluoroquinolones and one of the three injectibles, Kanamycin, Capreomycin and Amikacin. XDR-TB has been noted as an emerging health threat, especially in countries like India, with a high prevalence of HIV.


Why drug resistant TB?
Most experts believe that in India, the problem of drug resistance arises when patients stop taking the treatment prescribed to them. Dr. Chauhan says, in his article, “Contrary to popular belief I would like to say that many failures are due to failure to take treatment and not failure of treatment per se.”
A statement that is well borne out on the field. E. Subburam, State TB Officer, Tamil Nadu, says, “There are four main reasons why patients stop medication, leading to drug resistance. In our country, the primary reason is migration. Persons with alcohol and drug dependency are the second largest group of defaulters. Patients also stop treatment when after a month or two, the symptoms subside. In some cases, violent side-effects put the patient off the treatment.”


Stigma, however, continues to be an issue that comes in the way of effective treatment. Ratnam, a driver with the State-run transport corporation, works odd hours and therefore is unable to come to the DOTS [directly observed treatment strategy] centre to take his drugs. When his local DOTS centre offered to place the drugs in the bus terminus and appoint an employee there to give him the drugs, he refused. He did not want anyone to know he had TB, least of all his colleagues. So he dropped out, even as his treatment supervisor tried to find other ways of reaching the drugs to him.


In my experience too the fixed timings of DOTS centres is a big factor.Many working persons may not be able to reach the treatment centre which is usually open only on working days between 9am and 2pm.
Lack of awareness about the problems of default in taking medicines is another important factor.

Poverty and Tuberculosis

In Europe as society changed from predominantly rural to industrialized, crowding and poverty in metropolitan areas increased markedly, creating an environment in which M. tuberculosis was able to flourish. It is estimated that 20% of all deaths in London were due to TB during the late seventeenth century. This situation worsened, peaking in the UK in about 1780. This alarming state of affairs led to many social changes, and the incidence of TB started to decline in England from the mid 1800s, years before other infectious diseases, long before the discovery of M. tuberculosis and a century before the advent of antibiotics. This decline is attributed to an increased resistance in the population, better nutrition and improved housing and working conditions. In about 1870, food production exceeded population growth in Western Europe for the first time and higher wages from the industrial revolution allowed most citizens to purchase sufficient, nutritious food. The latter is a crucial factor, because it is known that a person who is 10% underweight has a threefold increased risk of developing TB after infection. Thus, the advent of antibiotics, although making a huge difference to individuals, had relatively little overall impact on the decline of TB in Europe.

Lesson for India

Europe in late 19th and early 20th century has proved that improved living conditions,better wages and good nutrition are the key factors that helps in arresting the TB epidemic. A strategy based purely on pharmoco therapy is destined to fail if we do not consider the larger socio-economic causes for the epidemic.

Tuberculosis is not just a medical problem, but also a problem of social inequality and poverty

Am I reassuring too much?

A patient always like to hear reassuring words from their Doctor.
A doctor is also happy to see the smile of relief on patient's face.
I reassure my patients a lot.But some times I ask myself
Am I reassuring too much?

The other day in my practise it was a day of reassurance.

First patient was a 29 year old woman,in the last few weeks of Pregnancy.She was diagnosed to have Gestational Diabetes.She is working in one of our Metros and was under the care of a specialised Gestational Diabetic Clinic there. Now she has come home for delivery and wanted me to look after her Diabetes.

She was on Insulin, 3 injections per day and was monitoring her blood sugar every day 2 to 3 times at home with her glucometer. She was given a long list of dos and dont's and a detailed diet chart.She was following everything perfectly.

After reading her reports I looked in her face.She seemed to be distressed. I asked her what was troubling her. She said her blood sugar is fluctuating very much and is afraid her baby will be harmed. She also said instead of gaining, she was loosing little bit of weight and is worried about.

The blood sugars were fluctuating but with in a narrow range and was well acceptable. When ever a small rise in blood sugar happens she is much worried that she reduces food intake. Some of the diet restrictions told to her from her speciality clinic was extreme and had not much scientific basis. Her mother is also confused about what food her daughter should be given. All the home grown wisdom of what to give and what not to give for a pregnant daughter was set aside and they were religiously following the diet chart.

I smiled at her and said " You are worrying too much. Your blood sugars are excellent and I am sure you will have a healthy baby and a normal delivery. Yes, you should regularly check your sugars but eat more liberally. Tell me what you really like to eat and I will tell you what quantity and how often you can eat your favourite dish."
That reassurance visibly made her happy. By next visit she started gaining weight and more importantly was at ease. I hope she will deliver normally a healthy child.

Next patient was a retired Government Clerk. He came to me few weeks ago with features of Cirrhosis Liver,probably due to alcoholism. He was send to a Gastroenterologist for detailed evaluation and was found to have severe Liver disease. He has come back with the reports.
"Is it really bad doctor?"
"Your Liver is affected by your drinking".
"I stopped the day I first came to you. Will the Liver function improve?"
"If you do not drink again you will definitely improve, don't worry", I said looking in to his eyes.
That was really not the truth.The reports showed he have irreversible liver damage and his liver function may deteriorate over several months to years. But his symptoms will temporarily improve with medicines. That's why I could confidently reassure him.
My answer I am sure made him feel better.

Third patient was a 64 year old Rheumatoid Arthritis patient. Her knee joints were so much destroyed that she needs Total knee replacement for both knees. Her family was not very well off . I had discussed it with her son and the family was not very keen to find the money for the surgery.
"Will I be able to walk properly and climb steps doctor?" She usually ask me.
" Let us see. You are showing some improvement.So if you continue the treatment......let us see."
In my mind I was sure she will not be able to walk properly. I had hinted to her once about surgery which she refused immediately citing old age. Also the family may not be able to afford it. So she will most probably go on like that using a walking stick, moving very slowly,swaying her body to either side till her death.
But each time she leaves my room, she is satisfied with my reassurance.

Am I reassuring too much?
Some times I do, hiding the gravity of the illness so that the patient is not too much upset. Some time I reassure prematurely before arriving at the diagnosis to avoid unnecessary mental tension.
Making the patient fully aware of the situation may help in avoiding future surprises.It may also help in compliance with therapy. So should I change my method?

I am confident I did do the correct thing in all three instances.
As the great TB physician Dr Edward Trudeau said
"To cure sometimes, to relieve often, to comfort always,"
should be the motto of each Physician.

"I cannot tell this to my wife doctor".

" I cannot tell this to my wife doctor.She will explode and may even take her own life".
A 43 year old man was telling this to me in my clinic.
He is HIV positive.He know about this for last 3 years.
I was asking him if he had tested his wife for HIV.
No he had not tested his wife.He had not told his wife yet. He is working in a far away place and visits his family only occasionally.

Are you using condom when you are with your wife? I asked.
'No' was his answer.

I did not know what to say.I had seen him 3 years ago when he was first found 'positive'.I had given a detailed lecture to him about what to do and what not to do.I had asked him to tell his wife about his 'positive' state.I had stressed on use of Condoms.
He had neither told his wife nor used condoms while having sex with her.

I was angry. "I can't treat you if you do not follow my advise". I threw his papers on the table. He and his friend who accompanied him started pleading.

" I cannot tell this to my wife doctor.She will explode and may even take her own life".

"What are you doing? You are now giving her infection and killing her.And you still say you are afraid she will commit suicide?"
I cannot ethically decline treating him. So what should I do?

I was confused. His CD4 cell counts are low and he should be started on ART. He is so afraid of stigma and discrimination that he is not willing to go to Government ART centre.

There is a law that says the doctor have to reveal the result to the spouse if she/he asks. I told him about it. From his face I could make out that he is mentally resolving never to bring his wife to me.

I had an idea.I should make him realise that telling his wife and testing her is also important for his health.

"I have to start you on anti viral medicines now.With in few months the number of viruses in your body will become very small.But if your wife is positive and you are having sex with her without condom the viral load will not decrease as your wife will transmit the virus to you."

He was confused first, I explained again to make him understand. Slowly he realised that it is important for his health that his wife is tested and given treatment if needed.Also the fact that having unsafe sex is unsafe not only for his wife but also for him.

He agreed to take his wife for testing. I gave prescription for 2 weeks and asked him to come back with the result of his wife's test. Will he do as I advised? I do not know.
But what a selfish man?

Summary

This blog is all about world immunizations. Immunizations protect child from dangerous diseases. They can also help reduce the spread of disease to others and prevent epidemics.

In many cases when you get a vaccine, you get a tiny amount of a weakened or dead form of the organism that causes the disease. This amount is not enough to give you the actual disease. But it is enough to cause your immune system to make antibodies that can recognize and attack the organism if you are ever exposed to it.

Immunizations protect both individuals and the larger population, especially those people who have immune system disorders and cannot be vaccinated. Getting immunized costs less than getting treated for the diseases that the shots protect you from.

The immunization schedule includes vaccines for Anthrax, Diphtheria, Haemophilus, Influenzae Type B (Hib), Hepatitis A, Hepatitis B, Human Papillomavirus (HPV), Influenza, Lyme Disease, Measles, Meningococcal disease, Mumps, Pneumococcal disease, Polio, Rabies, Rotavirus, Rubella, Shingles,, Smallpox, Tetanus, Tuberculosis, Typhoid Fever, Varicella, and Yellow Fever.

Reaction

People need to make sure that their vaccines are up to date. It is really important for child to be fully-immunized and also for adults for them to alleviated diseases that can be dangerous to their health. Newborn babies are immune to many diseases because they have antibodies they got from their mothers. However, the duration of this immunity may last only a month to about a year. Young children do not have maternal immunity against some vaccine-preventable diseases, such as whooping cough. If a child is not immunized and is exposed to a disease germ, the child's body may not be tough enough to fight the disease. Before vaccines, many children died from diseases that vaccines now prevent, such as whooping cough, measles, and polio. Those similar microorganisms exist today, but children are now secluded by vaccines, so we do not see these diseases as frequently.

Immunizing individual children also helps to protect the health of our community, especially those people who are not immunized. People who are not immunized include those who are too young to be vaccinated, those who cannot be vaccinated for medical reasons, and those who cannot make a sufficient response to vaccination. People who received a vaccine are also protected, but who have not developed resistance. In addition, people who are sick will be less likely to be exposed to disease microorganisms that can be passed around by unvaccinated children. Immunization also slows down or stops disease epidemics.

References:
http://www.keepkidshealthy.com/welcome/immunizations/immunization_timeline.html
http://www.healthgrades.com/kbase/topic/special/immun/sec1.htm
http://www.svcmc.org/body.cfm?id=841&action=detail&aeproductid=HW_Catholic&aearticleid=immun&AEArticleType=Special
http://www.immunizenc.com/YellowFever.htm
http://www.immunizationinfo.org/vaccineInfo/
http://kidshealth.org/parent/infections
http://www.cdc.gov/flu/protect/keyfacts.htm

Anthrax
There is a vaccine to prevent anthrax, but it is not yet available for the general public. Anyone who may be exposed to anthrax, including certain members of the U.S. armed forces, laboratory workers, and workers who may enter or re-enter contaminated areas, may get the vaccine. Also, in the event of an attack using anthrax as a weapon, people exposed would get the vaccine.

Diptheria
Diphtheria causes a thick covering in the back of the throat. It can lead to breathing problems, paralysis, heart failure, and even death. There are several combination vaccines used to prevent diphtheria: DTaP, Tdap, DT, and Td.

Hepatitis A
Hepatitis A is a liver disease caused by the hepatitis A virus (HAV). Hepatitis A can affect anyone. Vaccines are available for long-term prevention of HAV infection in persons 1 year of age and older. Good personal hygiene and proper sanitation can also help prevent the spread of hepatitis A.

Hepatitis B
Hepatitis B is a serious disease caused by a virus that attacks the liver. The virus, which is called hepatitis B virus (HBV), can cause lifelong infection, cirrhosis (scarring) of the liver, liver cancer, liver failure, and death. Hepatitis B vaccine is available for all age groups to prevent HBV infection.

Haemophilus Influenzae type b (Hib)
Haemophilus influenzae type b vaccine prevents meningitis (an infection of the covering of the brain and spinal cord), pneumonia (lung infection), epiglottitis (a severe throat infection), and other serious infections caused by a type of bacteria called Haemophilus influenzae type b. It is recommended for all children under 5 years old in the U.S., and it is usually given to infants starting at two months old. The Hib vaccine can be combined with other vaccines. In the U.S., Hib vaccine is available also combined with either DTaP or Hep B vaccine.

Influenza
The single best way to prevent the flu is to get a flu vaccination each year. There are two types of vaccines:

1. The "flu shot"— an inactivated vaccine (containing killed virus) that is given with a needle, usually in the arm. The flu shot is approved for use in people older than 6 months, including healthy people and people with chronic medical conditions.

2. The nasal-spray flu vaccine — a vaccine made with live, weakened flu viruses that do not cause the flu (sometimes called LAIV for “live attenuated influenza vaccine” or FluMist®). LAIV (FluMist®) is approved for use in healthy* people 2-49 years of age† who are not pregnant.

The viruses in the vaccine change each year based on international surveillance and scientists' estimations about which types and strains of viruses will circulate in a given year.

Human Papilloma Virus
Human Papillomavirus (HPV) is a common virus that is spread through sexual contact. Most of the time HPV has no symptoms so people do not know they have it.

Lyme Disease
Lyme disease (LD) is transmitted to humans by the bite of infected blacklegged ticks. The vaccine for Lyme disease is no longer available. It was discontinued by the manufacturer in 2002, citing low demand. People who were previously vaccinated with the LD vaccine are no longer protected. Most cases of Lyme disease can be treated successfully with a few weeks of antibiotics. Steps to prevent Lyme disease include using insect repellent, removing ticks promptly, landscaping, and integrated pest management.

Measles
Measles is the most deadly of all childhood rash/fever illnesses. The disease spreads very easily, so it is important to protect against infection. To prevent measles, children (and some adults) should be vaccinated with the measles, mumps, and rubella (MMR) vaccine. Two doses of this vaccine are needed for complete protection. Children should be given the first dose of MMR vaccine at 12 to 15 months of age. The second dose can be given 4 weeks later, but is usually given before the start of kindergarten at 4 to 6 years of age.

Meningococcal
Meningococcal vaccines protect against most types of meningococcal disease, although they do not prevent all cases. There are two vaccines against Neisseria meningitidis available in the United States: meningococcal polysaccharide vaccine (MPSV4 or Menomune®), and meningococcal conjugate vaccine (MCV4 or Menactra®).

Mumps
Mumps vaccine (usually MMR), is the best way to prevent mumps. Children should be given the first dose of MMR vaccine soon after the first birthday (12 to 15 months of age). The second dose is recommended before the start of the kindergarten. You should know that outbreaks of mumps still occur in the United States

Pertussis (Whooping cough)
Whooping cough, known medically as pertussis , is a highly contagious respiratory tract infection. Although it initially resembles an ordinary cold, whooping cough may eventually turn more serious, particularly in infants. Whooping cough is most contagious before the coughing starts. The best way to prevent it is through vaccinations. The childhood vaccine is called DTaP. The whooping cough booster vaccine for adolescents and adults is called Tdap. Both protect against whooping cough, tetanus, and diphtheria.

Pneumococcal conjugate vaccine
Pneumococcal conjugate vaccine is recommended for all children less than 59 months old. In addition, children aged more than 24 months who are at high risk of pneumococcal disease and adults with risk factors may receive the pneumococcal polysaccaride vaccine (Pneumovax®).

Polio
Polio is an infectious disease caused by a virus that lives in the throat and intestinal tract. It is most often spread through person-to-person contact with the stool of an infected person and may also be spread through oral/nasal secretions. Polio used to be very common in the U.S. and caused severe illness in thousands of people each year before polio vaccine was introduced in 1955. Most people infected with the polio virus have no symptoms, however for the less than 1% who develop paralysis it may result in permanent disability and even death.

There are two types of vaccine that protect against polio:

Inactivated Polio Vaccine (IPV) and Oral Polio Vaccine (OPV). IPV, used in the U.S. since 2000, is given as an injection in the leg or arm, depending on age. Polio vaccine may be given at the same time as other vaccines. Most people should get polio vaccine when they are children. Children get 4 doses of IPV, at these ages: 2 months, 4 months, 6-18 months, and booster dose at 4-6 years. OPV has not been used in the United States since 2000 but is still used in many parts of the world.

Rabies
Preexposure vaccination is recommended for persons in high-risk groups, such as veterinarians, animal handlers, and certain laboratory workers. Although preexposure vaccination does not eliminate the need for additional medical attention after a rabies exposure, it can decrease the number of vaccine doses needed, and it minimizes adverse reactions to multiple doses of vaccine.
Rabies is an acute and deadly disease caused by a viral infection of the central nervous system. The rabies virus is most often spread by a bite and saliva from an infected (rabid) animal (e.g., bats, raccoons, skunks, foxes, ferrets, cats, or dogs). In the United States, rabies is most often associated with bat exposures. However, there have been rare cases in which laboratory workers and explorers in caves inhabited by millions of bats were infected by rabies virus in the air.
The rabies vaccine is available as:
-Human diploid cell vaccine (HDCV)
-Purified chick embryo cell culture (PCEC)
-History of the Vaccine
-The first rabies vaccine was developed in the early 1960's. All rabies vaccines currently available are made from killed rabies virus.

Who should receive the vaccine pre-exposure?
Vaccination before exposure (pre-exposure) should be offered to people in high risk groups such as veterinarians, animal handler/caretakers, or laboratory workers who may be exposed to the rabies virus.

Who should receive the vaccine post-exposure?
Vaccination after exposure (post-exposure) is recommended for all individuals who have had contact with an animal (e.g., bites or abrasions) that they believe may be, or which is proven to be, rabid.

Who should not receive the vaccine?
The rabies vaccines are not recommended for routine use.
People who are moderately or severely ill should consult with their physician before receiving any vaccine.

This vaccine is recommended by:
-Advisory Committee of Immunization Practices of the Centers for Disease Control and Prevention
-American Academy of Pediatrics
-American Thoracic Society

Effectiveness of the Vaccine
Although all rabies vaccines licensed in the U.S. induce protective antibody levels after three doses in nearly 100% of recipients, it is important to complete the dose schedules recommended for individual circumstances (see Dose Schedule). Previously immunized people still must receive two additional doses of the vaccine if exposed to the virus, and the vaccine is almost 100% effective in these cases as well.


Known Side Effects
Mild reactions such as pain, redness, swelling, or itching at injection site are reported among 30%-74% of those vaccinated. Headache, nausea, abdominal pain, muscle aches, and dizziness are reported in 5-40% of those vaccinated.
Serious events after vaccination are rare. However, allergic reactions including swelling and mild difficulty breathing developed in 6% of patients who received booster doses of Human Diploid Cell Rabies Vaccine. In addition, three cases of neurologic illness resembling Guillain-Barre Syndrome, a progressive disorder affecting the nervous system, have been reported in people who receive the Human Diploid Cell Rabies Vaccine. In these cases, all patients recovered within three months.

Rotavirus
Rotavirus is the leading cause of severe acute gastroenteritis (vomiting and diarrhea) among children worldwide. The rotavirus vaccine currently licensed in the United States, Rotateq, has shown to be quite effective against rotavirus disease. This vaccine will prevent 74 percent of all rotavirus cases, about 98 percent of severe cases, and about 96 percent of hospitalizations due to rotavirus.
Rotaviruses are intestinal viruses that infect virtually all children by three years of age. It is the most common cause of diarrhea in children, including hospital-acquired diarrhea; childcare center outbreaks are common. The illness often also includes fever and vomiting, lasts a week or longer, and can cause persistent infection in immunocompromised people. Most rotavirus infections are mild, but about 1 in 50 cases develop severe dehydration. Each year in the United States, rotavirus infections resulted in 22.5 hospitalizations and 301 emergency room visits per 10,000 children less than 3 years of age. That is, 1 in 150 children were hospitalized because of rotavirus infection and another 1 in 11 visited an emergency room or visited an outpatient clinic for rotavirus infection. In developing countries, rotavirus leads to an estimated 480,000 to 640,000 deaths each year.

History of the Vaccine
The rotavirus vaccines currently available in the US are both attenuated (weakened) live virus vaccines: Rotateq® is a pentavalent human-bovine reassortant rotavirus vaccine licensed in 2006 and RotaRix® is a monovalent attenuated human rotavirus licensed in 2008. Both vaccines are given by mouth.
A previously released rotavirus vaccine, RotaShield®, was withdrawn from the market in 1999. RotaShield®, was a tetravalent, reassortant rhesus-human rotavirus vaccine licensed by the Food and Drug Administration (FDA) in August 1998. However, in July 1999, after approximately 1 million children had been immunized with that vaccine, the CDC suspended its recommendation because they detected an increase in the number of children who developed a serious bowel disease called "intussusception." Investigators calculated that the risk of intussusception attributable to the vaccine was about 1 per 10,000 infants vaccinated which was about three times higher than for unvaccinated children. That vaccine was voluntarily withdrawn from the market by the manufacturer in October 1999. Those who received the RotaShield® vaccine in 1998 and 1999 do not have a continuing risk of developing intussusception.

Who should receive the rotavirus vaccine?
-All full term infants should begin the series between the ages of 6-14 weeks of age. Breast fed infants can receive rotavirus vaccine.
-There is limited information on the immunization of infants born at less than 37 weeks gestation but consideration should be given for immunization of these children because they may be at increased risk for hospitalization from gastroenteritis in the first year of life.

Who should not receive the rotavirus vaccine?
-The vaccine series should not be initiated after 15 weeks of age.
-These vaccines should not be administered after 7 months of age because of insufficient data on vaccine safety in children who are 8 months of age and older.
-A child who has had a life-threatening allergic reaction to a previous dose or a component of the vaccine should not get another dose.
-A child who has had life-threatening allergic reaction to latex rubber should not receive the RotaRix® vaccine which is packaged in a latex applicator.
-There is no safety information for administration of rotavirus vaccine to infants who are immunocompromised. However, both children and adults who are immunocompromised because of congenital immunodeficiency or following transplantation can experience severe and potentially fatal rotavirus gastroenteritis.
-Infants who have received blood products should have the vaccine postponed for 6 weeks unless that delay might make the child ineligible for vaccination because of age.
-There is no safety information related to the administration of vaccine to infants with gastroenteritis. It is recommended that rotavirus vaccine not be administered to infants with acute, moderate-to-severe gastroenteritis but be considered for administration to infants with mild gastroenteritis if the delay might make the child ineligible for vaccination because of age.

Effectiveness of the Vaccine
Both RotaTeq® and RotaRix® have been shown to be effective against rotavirus gastroenteritis of any severity and both have high efficacy against severe rotavirus gastroenteritis.

Known Side Effects
Children may be more likely to experience mild, temporary diarrhea or vomiting within 7 days after getting a dose of rotavirus vaccine than children who have not gotten the vaccine.
No moderate or severe reactions have been associated with these vaccines.

Rubella Vaccine
Rubella is caused by a virus that is transmitted from person to person in mucus droplets coughed or sneezed into the environment. Rubella usually is a mild illness. Symptoms include low-grade fever and swollen lymph nodes in the back of the neck followed by a generalized rash. Complications may include joint pain, a temporary decrease in platelets, and encephalitis (inflammation of the brain). Temporary arthritis may also occur, particularly in adolescents and adult women.
The rubella vaccine is available as:
· MMR (Measles-Mumps-Rubella)
· MMRV (Measles-Mumps-Rubella-Varicella Virus Vaccine Live)
· Rubella (alone)

History of the Vaccine
The first vaccines for rubella were licensed in 1969. Today rubella vaccine is generally given in combination with measles and mumps vaccines (MMR).
Originally, just one dose of the MMR vaccine was recommended. In 1989, the American Academy of Family Physicians, the American Academy of Pediatrics, and the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices, changed the recommendation to two doses, primarily to immunize the small percent of people who do not respond to the measles component of the MMR vaccine. This change and a higher vaccination rate have nearly eliminated these three diseases in the United States.

Who should not receive the MMR vaccine?
-People with serious allergies to gelatin or any of the other components of the vaccine
-Women who are pregnant or trying to conceive. Moreover, women should not become pregnant within 28 days after immunization with MMR.
-Immunocompromised persons (with the exception of HIV-infected persons who have no symptoms of AIDS, as noted above) and persons receiving cancer chemotherapy or high doses of steroids
-People receiving blood products (except washed red blood cells) such as immune globulin should have the MMR vaccine deferred for 3 to 11 months depending on the blood product and dosage administered.
-People who are moderately or severely ill should consult with their physician before receiving any vaccine.

Who should receive the rubella vaccine?
-People who cannot receive one or both of the other vaccines included in MMR
-People who have proof of immunity to one or both of the diseases that MMR prevents may receive the rubella vaccine, though MMR is usually recommended

Effectiveness of the Vaccine
Ninety-five percent of those who receive the MMR or rubella vaccine at one year of age or older are immune after the first dose. Immunity is lifelong.

Known Side Effects
Nearly all children who get the MMR vaccine (more than 80%) will have no side effects. Most children who have a side effect will have only a mild reaction, such as soreness, redness or swelling where the shot was given, mild rash, mild to moderate fever, swelling of the lymph glands, and temporary pain, stiffness, or temporary swelling in the joints.

Shingles (Herpes-Zoster)
Zoster (shingles) is an infection caused by the varicella-zoster virus (VZV), the cause of chickenpox. The VZV virus—which remains in the nerve cells for life after chickenpox or after the chickenpox vaccine—may reappear as shingles in later life, particularly in the elderly and those who are immunocompromised. This is because of declining immunity to the VZV virus over time. Thus, anyone who has had chicken pox or the chickenpox live virus vaccine is at risk for developing shingles. While shingles can occur at any age, the risk increases as people get older. When shingles develop, a rash or blisters appear on the skin, generally on one side of the body. The skin blisters in shingles contain the VZV virus so chickenpox-susceptible children can develop chickenpox when exposed to shingles.
Because the infection in shingles starts in the nerves, shingles can also be painful. Pain can last for months after the rash has healed and can be very severe—this is called post herpetic neuralgia or PHN. Shingles occurs most commonly in older individuals and PHN is a more common complication of shingles in older individuals.

History of the Vaccine
A varicella vaccine developed in Japan in the 1970’s was licensed for routine use in Japan and Korea in 1988. The varicella vaccine was recommended for routine use in the United States in 1995. Zostavax is very similar to varicella vaccine but contains a higher dose of the vaccine virus. In 2006, Zostavax was licensed and recommended for routine administration to adults over the age of 60 years.

Who should receive the vaccine?
Individuals 60 years of age and older.

Who should not receive the vaccine?
-Children should not receive Zostavax; it is not a substitute for varicella vaccine (Varivax).
-People who have had a life-threatening allergic reaction to gelatin, to the antibiotic neomycin, or to a previous dose of the chickenpox vaccine.
-Persons with primary or acquired immunodeficiency states including leukemia, lymphoma of any type, other malignant neoplasm affecting the bone marrow or lymphatic system or AIDS or other clinical manifestations of infection with human immunodeficiency viruses.
-Persons who are taking immunosuppressive therapy, including high-dose corticosteroids.
-Persons with active untreated tuberculosis.
-Women who are or may be pregnant

Effectiveness of the Vaccine
In a clinical trial of more than 38,000 individuals over 60 years of age, about half of whom received the vaccine, Zostavax reduced the occurrence of shingles by about 50%. Effectiveness was greatest in the younger age groups and declined with advancing age. In those who had received the vaccine and who developed shingles, the duration (but not the severity) of PHN was reduced.

Known Side Effects
Serious adverse events (death, hospitalization) were similar for vaccine and placebo recipients. Discomfort, redness or swelling at the injection site occurred in about 48% of vaccine recipients


Smallpox
Most people in the U.S.—indeed in the world—have not considered smallpox a health threat for several decades. Smallpox hasn't occurred in the U.S. since 1949, and routine vaccination against it ended here in 1972. When the World Health Organization (WHO) certified that smallpox had been eradicated from the planet in 1980, this was the first time in history that medical scientists and public health workers had completely purged the world of a devastating infectious disease.
Though the disease was eradicated over 20 years ago, several samples of the live virus were preserved, mainly for research purposes. Today the only verified repositories of the virus are held in secure laboratories at the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, and the State Center for Research on Virology and Biotechnology in Koltsovo, Russia. However, it is believed that clandestine stocks of smallpox exist in 10 or more other countries.
Smallpox is caused by the variola virus, which can be spread from person to person via respiratory droplets produced in the nose, mouth, and throat of someone who is infected and has begun to show signs of illness. After a person has been exposed to the virus, there is an incubation period of between 7 and 17 days prior to the onset of symptoms, which include high fever, severe headache and backache, and often vomiting and tremors. Two to five days later, the characteristic smallpox rash develops. It begins as flat, round lesions, primarily on the face and forearms, and evolves into deep, pus-filled blisters that may cover the entire body, including the palms and soles of the feet. Some patients have a fever throughout the course of the rash (two to four weeks), and often the blisters cause significant pain. In the last stage of the rash scabs form and fall off, leaving pitted scars. Some smallpox survivors are blind as a result of deep scarring in the eye area. Smallpox during pregnancy often results in miscarriage or stillbirth.

History of the Vaccine

An English physician named Edward Jenner observed that many milkmaids who contracted cowpox, a disease in cows that causes only mild illness in humans, either did not contract smallpox or had milder disease and lower mortality. In 1796, he experimented by taking the fluid from a cowpox blister on a milkmaid’s hand and administering it to a young boy through incisions on his arm. Jenner discovered that exposing the boy to the cowpox virus protected him from smallpox. This experiment was the first scientific attempt to control an infectious disease through vaccination. In fact, the word vaccine comes from the Latin word for cow, vacca. The smallpox vaccine later developed and administered today in very limited circumstances uses the vaccinia virus (a virus closely related to cowpox) to induce an immune response, and does not contain smallpox virus.

Who should receive the vaccine?
The smallpox vaccine is not currently recommended for or available to the general public in the U.S. The smallpox vaccine is now available under limited circumstances, for example:
-Department of Defense military and civilian personnel and State Department personnel who work in high threat areas
-Healthcare providers and “first responders” who volunteer for smallpox response teams
-For laboratory workers and others at risk for exposure to the smallpox virus, or closely related viruses
-Participants in smallpox vaccine clinical trials

Who should not receive the vaccine?
When the vaccine was routiney administered in the U.S., it was not given to:
-Children under one year of age
-People with eczema, atopic dermatitis, a history of eczema, another unresolved skin condition (including burns), or a household contact with eczema or a history of eczema
-People with weakened immune system (such as those undergoing chemotherapy or who have received organ transplants), or a household contact with a weakened immune system
-People with HIV-infection (Although HIV and AIDS were unknown at the time that smallpox vaccination was given routinely to U.S. civilians, military personnel continued to be vaccinated until 1990. In at least one instance, a military recruit with HIV had a severe adverse reaction to vaccinia vaccine.)
-Pregnant women

Tetanus

Tetanus (Lockjaw) is caused by toxin-producing spores of a bacterium Clostridium tetani that inhabit the soil and the bowels of animals and humans. Unlike other vaccine-preventable diseases, it is not spread from person to person. Tetanus may occur following delivery in the newborn babies of unimmunized women. Tetanus infection is most often the result of wound contamination in an unimmunized person or someone who has not had vaccine boosters in many years. It may also occur following puncture wounds, animal bites, burns, abrasions and surgery.
The tetanus toxin causes severe muscle contractions, or spasms. Fever, sweating, elevated blood pressure, and rapid heart rate may also occur. Spasms of the vocal cords or the muscles of respiration can interfere with breathing, and pneumonia is common. Contraction of muscles can be so severe that the spine or other bones are fractured.

The tetanus vaccine is available as:
DTaP (Diphtheria-Tetanus-Pertussis)
DTaP in combination with Haemophilus influenzae type b (Hib) vaccine
DTaP in combination with hepatitis B and inactivated polio vaccines
DTaP in combination with Hib, hepatitis B and inactivated polio vaccines
Tdap (Diphtheria-Tetanus-Pertussis)
DT or Td (in combination with diphtheria vaccine)
TT (alone)

Who should receive the vaccine?
-Most infants and children younger than seven years of age should receive DTaP beginning at two months of age.
-For children who are younger than 7 years of age for whom there is a reason to not give a pertussis-containing vaccine, the TD can be administered.
-For children seven to nine years of age, the Td vaccine can be administered for initial catch-up immunization.
-For persons seven years of age and older, the Td vaccine should be administered every 10 years to provide continued immunity against diphtheria and tetanus and for tetanus prophylaxis for a tetanus prone injury if more than 5 years have elapsed since the last dose of a tetanus toxoid-containing vaccine.
-11-18 year olds should receive a single dose of Tdap instead of a Td booster if they have completed the recommended childhood DTP/DTaP immunization series and have not received Td or Tdap. The preferred age for Tdap vaccination is 11-12 years. If they have already received a Td booster, it is recommended that there be an interval of at least 5 years before Tdap is administered to reduce the likelihood of local and systemic reactions.

Who should not receive the vaccine?

-Those with a history of a serious allergic reaction (such as anaphylaxis) to any of the vaccine components.
-Those with a history of encephalopathy (e.g. coma or prolonged seizures) not attributable to an identifiable cause within 7 days of administration of a vaccine with pertussis components should not receive a pertussis-containing vaccine.
-Pertussis-containing vaccines (including the DTaP vaccine) are not currently recommended for children who are 7-9 years of age.
-Tdap is not recommended to be administered within 2 years after the most recent tetanus toxoid-containing vaccine.

Effectiveness of the Vaccine
The DTaP vaccine is 95% effective in preventing all three diseases that it immunizes against--diphtheria, tetanus and pertussis. It is virtually 100% effective in preventing tetanus, while the protection rates for diphtheria and pertussis are lower. Immunity against tetanus lasts about 10 years; therefore a booster dose of Td (tetanus-diphtheria) vaccine is needed every 10 years to maintain immunity.

Known Side Effects
The DTaP vaccine is 95% effective in preventing all three diseases that it immunizes against--diphtheria, tetanus and pertussis. It is also about 95% effective in preventing diphtheria, while the protection rates are lower for pertussis and higher for tetanus. Immunity against diphtheria lasts about 10 years; therefore a booster dose of Td (tetanus-diphtheria) vaccine is needed every 10 years to maintain immunity. If exposed to diphtheria, partially immunized individuals can acquire the disease, although generally it is less severe than in unimmunized people.

Tuberculosis
Tuberculosis is caused by the bacterium Mycobacterium tuberculosis. It is generally spread in mucus droplets coughed out by infected people.
Most people with tuberculosis show no symptoms at the time of infection. People who develop symptoms usually do so within one to six months after the start of the infection. Symptoms include fever, night sweats, chills, and cough. Pneumonia, lung collapse, and enlarged lymph nodes may also occur.
The most common form of tuberculosis affects the lungs. Two forms of tuberculosis that become life-threatening are:
Miliary TB, which means the bacteria have spread throughout the lungs and into the bloodstream
TB meningitis (infection of the coverings of the spinal cord and/or brain by TB bacteria)

History of the Vaccine
The TB vaccine is a live, weakened bacterial vaccine made from the bacterium that causes TB in cows. It was first administered to humans in 1921. It has been given to 4 billion people worldwide and has been used routinely since the 1960’s in almost all the countries of the world, primarily in young infants. Changes in the TB bacteria over time have led scientists to create the different TB vaccines used throughout the world, and their effectiveness appears to be highly variable.


Who should receive the vaccine?
Although TB vaccine is recommended by the World Health Organization and is given in more than 100 countries, in the U.S. it should only be considered in select circumstances. In the U.S., the vaccine should be considered for infants and children who do not test positive for TB but who are:
-Continually exposed to a patient with infectious TB of the lungs (and the child cannot be removed from this person)
-Exposed to a person with TB that is resistant to antituberculosis drugs
-In addition, vaccination is recommended for health care workers who are employed in settings with patients who have drug-resistant TB, and where comprehensive TB infection-control precautions have been implemented but have not been successful.

Who should not receive the vaccine?
-HIV-infected children or children whose immune systems are not functioning fully (e.g., patients undergoing chemotherapy)
-People with burns or skin infections
-Pregnant women
-People who are moderately or severely ill should consult with their physician before receiving any vaccine.

This vaccine is recommended by:
-Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention
-American Academy of Pediatrics
-American Thoracic Society

Effectiveness of the Vaccine
Studies examining vaccine’s effectiveness against tuberculosis of the lungs have drawn various conclusions; however, one large study found the vaccine to protect about 50% of recipients. Effectiveness rates are highest among those who get the vaccination in early childhood.
Those who receive the vaccine may still develop TB, but approximately 80% of recipients are protected from developing life-threatening forms of the disease, such as miliary disease and meningitis (inflammation of the brain).

Known Side Effects
Accurate rates of adverse events due to the TB vaccine are difficult to estimate, but serious or long-term complications after TB immunization are uncommon.
Frequent reactions to the TB vaccine include redness, swelling, or soreness at the injection site.
Moderate swelling of the lymph nodes in the armpits or neck, which may progress to pus-filled.

Typhoid Fever
Typhoid fever is a serious disease caused by the bacterium called Salmonella enterica serotype Typhi (S. Typhi).
The infection is spread from person-to-person by the fecal-oral route. That means that people get typhoid from food or water contaminated with the feces of infected people. Typhoid symptoms include high fever, weakness, stomach pains, headache, loss of appetite, and sometimes a rash. Infection can spread to many other places in the body (such as bones) and can cause rupture of the intestine. It kills up to 30% of people who get it, if they are not treated.
Some people who become infected with S. Typhi become chronic carriers—they have no symptoms but have S. Typhi in their feces. Chronic carriers can spread S. Typhi to other people especially when handling food.
Antibiotic therapy reduces deaths and complications caused by typhoid fever. However, in recent years S. Typhi has acquired resistance to many of the antibiotics most widely available for its treatment. Typhoid vaccine can reduce the risk of illness in those who are exposed to S. Typhi.
According to the World Health Organization, 16 million people get typhoid every year around the world and about 600,000 die from the disease.
Typhoid is not common in the United States. Although 356 cases of typhoid fever were reported in the US in 2003, most of these infections are acquired during travel to other parts of the world or by contact with someone who is a carrier—either someone who has recently traveled or is a chronic carrier of S.Typhi.

History of the Vaccine
During the past 15 years, the two typhoid vaccines licensed in the US have been widely used globally. These vaccines have largely replaced the old heat-phenol inactivated whole-cell vaccine in many countries, including the US.

Who should receive the vaccine?
Typhoid fever is rare in the United States, so routine typhoid vaccination is not recommended. However, the following people should receive the vaccine:
- Travelers to parts of the world where typhoid fever is common. Risk is greater for travelers to the Indian subcontinent, Latin America, Asia, and Africa who may have exposure to contaminated food and drink. Since typhoid vaccine is not 100% effective, it is not a substitute for being careful about what you eat or drink.
- People in close contact with a typhoid carrier (for example, household contacts).
- Laboratory workers who work with S.Typhi
Who should not receive the Polysaccharide Typhoid Vaccine (Shot)?
- Persons who have had a severe reaction to a previous dose of this vaccine should not get another dose.
- Children less than 2 years of age
- Who should not receive the live attenuated Typhoid Vaccine (Oral)?
- Persons who have had a severe reaction to a previous dose of this vaccine should not get another dose.
- Immunocompromised persons (for example, persons with HIV/AIDS, persons receiving cancer chemotherapy, or persons receiving high doses of corticosteroids). They should get the polysaccharide typhoid vaccine instead.
- Oral typhoid vaccine should not be given within 24 hours of taking certain antibiotics.
- Children less than 6 years of age

Effectiveness of the Vaccine
The efficacy of the two licensed vaccines ranges from 50% to 80%.
The oral vaccine has shown a protective efficacy of 62% for at least seven years after the last dose. The inactivated vaccine for its part, showed a 55% efficacy in a recent study in South Africa three years after immunization of children 5 to 16 years of age.

Known Side Effects
The two typhoid vaccines licensed in the US have few adverse reactions. Most reactions that do occur are mild. Reactions to the oral typhoid vaccine include fever or headache (5%), abdominal discomfort, nausea, vomiting, or rash (rare). Reactions to the inactivated vaccine include fever (1%); headache (3%); and redness or swelling at the site of the injection (7%).

Nodes that require drainage in some people, also occurs. In addition, swelling at the injection site may turn into a pustule and then a scar. An ulcer may develop where the shot was given in some people. These reactions occur after approximately 1% to 2% of immunizations, and may last three months or longer.

Varicella
Varicella (chickenpox) is an infection caused by the varicella-zoster virus (VZV). The infection usually starts as a rash on the face that spreads to the rest of the body. The rash begins as red bumps that eventually become blisters. A child will often get 300 to 500 blisters during the infection, which crust over and fall off in one to two weeks. The virus can be spread in the fluid from the blisters or droplets from an infected person’s nose or throat.
Varicella is generally a mild disease, but it is highly contagious and can be severe and even fatal in otherwise healthy children (less than 1 out of every 10,000 cases). Chickenpox can cause pneumonia (23 out of every 10,000 cases), and is an important risk factor for developing severe invasive “strep” (group A streptococcal disease), commonly referred to as “flesh-eating disease.” Treatment of this deep infection requires antibiotics and surgery to remove the infected tissue. Complications of varicella include bacterial infections (up to 5% of cases), decreased platelets, arthritis, hepatitis, and brain inflammation (1 in 10,000 cases), which may cause a failure of muscular coordination. Complications are more common among adolescents and adults, and in immunocompromised persons of all ages, than in children.

History of the Vaccine
A varicella vaccine developed in Japan in the 1970’s was licensed for routine use in Japan and Korea in 1988. The varicella vaccine was recommended for routine use in the United States in 1995. In 2005, a measles, mumps, rubella, varicella combination vaccine was licensed. In 2006, a second dose of a varicella-containing vaccine was recommended.

Who should receive the vaccine?
-All children aged 12 to 18 months
-All older children and adults who have not had chickenpox and have not been vaccinated
-If someone who has never had chickenpox disease or received the vaccine is exposed to chickenpox, giving him or her the vaccine within 72 hours will probably prevent or significantly reduce the severity of the disease. It is recommended under such circumstances.

Who should not receive the vaccine?
-People who have had a life-threatening allergic reaction to gelatin, to the antibiotic neomycin, or (for those needing a second dose) to a previous dose of the chickenpox vaccine
-Those who are receiving the MMR vaccine simultaneously should not get the varicella vaccine from the same needle or in the same place on the body.
-Pregnant women should wait until after they give birth to receive the vaccine. Women should not become pregnant for at least one month after receiving the vaccine. To date, there are no reported cases of congenital varicella syndrome caused by the vaccine.
-Persons with T-lymphocyte immunodeficiency, including those with leukemia, lymphoma, other malignancies affecting the bone marrow and congenital T-cell abnormalities. The vaccine may be given to children with acute lymphocytic leukemia under study conditions, and HIV-infected persons who are immunocompetent may be vaccinated. Susceptible family members and other contacts of HIV-infected or immunodeficient persons should receive the chickenpox vaccine, because of the risk that natural chickenpox and its complications present for these patients.
-Varicella vaccine should not be given for five months following the receipt of antibody-containing (e.g., blood transfusion) products.

Effectiveness of the Vaccine
Varicella vaccine is 85% to 90% effective for prevention of varicella and 100% effective for prevention of moderate or severe disease.
Children receiving varicella vaccine in pre-licensure trials in the United States have been shown to be protected for 11 years. Studies in Japan have demonstrated protection for at least 20 years. However, breakthrough infection (i.e., cases of chickenpox after vaccination) can occur in some who have been immunized. Although breakthrough varicella usually results in mild rather than severe illness, some school outbreaks have resulted in some children with more lesions and them also being contagious. For this reason, a second dose of a varicella-containing vaccine is recommended.

Known Side Effects
A majority of people who get the vaccine have no side effects. Of those who do have side effects, most will have only a mild reaction such as soreness and swelling where the shot was administered, and a mild rash.
In very rare cases (far less than 1 child out of 10,000 vaccinated or 0.02% of cases), children have a serious reaction that can include seizures caused by high fever.
MMRV combination vaccine has comparable rates of reactions to children who received MMR and varicella vaccine at different sites—except that those that received MMRV vaccine more commonly experienced fever, a measles-like rash and rash at the injection site.

Yellow Fever
Yellow fever is caused by a virus that is carried by a biting mosquito. Only humans and monkeys can be naturally infected with yellow fever virus. A mosquito that is capable of transmitting yellow fever virus is present in southern parts of the United States.
Epidemic yellow fever used to occur in the United States but now the disease occurs only in sub-Saharan Africa and tropical South America, where it is endemic and intermittently epidemic. There are 200,000 estimated cases of yellow fever (with 30,000 deaths) per year. However, due to underreporting, only a small percentage of these cases are identified. Small numbers of imported cases also occur in countries free of yellow fever.
Infection causes a wide spectrum of disease. Most cases of yellow fever are mild and similar to influenza, consisting of fever, headache, nausea, muscle pain and prominent backache. After three to four days most patients improve and their symptoms disappear. However, in about 15% of patients, fever reappears after 24 hours with severe illness which includes hepatitis and hemorrhagic fever. Bleeding can occur from the mouth, nose, eyes and/or stomach. Once this happens, blood appears in the vomit and feces. Kidney function also deteriorates. Half of those who develop the severe illness die within 10-14 days. The remainder recovers without significant organ damage.
The "yellow" in the name is explained by the jaundice that occurs with hepatitis.
The isolation of the Asibi and French strains of yellow fever in 1927 enabled the development of vaccines. Scientists at the Rockefeller Foundation in New York developed a live vaccine (17D) attenuated by serial passage of the Asibi strain in embryonated chicken eggs. The 17D vaccine was first tested in 1936 in New York and in 1937 in Brazil.
Although the vaccine has been available for more than 60 years, the number of people infected over the last two decades has increased and yellow fever is now a serious public health issue in a number of countries once again.

Who should receive the yellow fever vaccine?
-All persons 9 months or older of age traveling to or living in areas where yellow fever infection is reported or yellow fever vaccination is required. The vaccine is recommended for all travelers passing through or living in countries in Africa, Central America and South America where yellow fever infection is officially reported. It also is recommended for travel outside the urban areas of countries that do not officially report yellow fever but lie in the yellow fever “endemic zones.”
-A vaccination certificate is required for entry to many countries, particularly for travelers arriving in Asia from Africa or South America. Fatal cases in unvaccinated tourists have been reported with an average of one a year for the past ten years.

Who should not receive the yellow fever vaccine?
-Yellow fever vaccine should not be given to infants under 6 months of age due to a risk of viral encephalitis (brain inflammation) developing in the child. In most cases, vaccination should be deferred until the child is 9 to 12 months of age to minimize the risk of vaccine associated encephalitis.
-Pregnant women should not be vaccinated because of a theoretical risk that the developing fetus may become infected from the vaccine.
-Infants 6 to 9 months of age and pregnant women should be considered for immunization only if they are traveling to high-risk areas, travel cannot be postponed and a high level of prevention against mosquito exposure is unfeasible.
-Persons hypersensitive to eggs should not receive the vaccine because it is prepared in embryonated eggs.
-Immunocompromised persons and persons receiving cancer chemotherapy or high doses of steroids. People with asymptomatic HIV infection may be vaccinated if exposure to yellow fever cannot be avoided.

Effectiveness of the Vaccine
Vaccination is the single most important measure for preventing yellow fever. In populations where vaccination coverage is low, vigilant surveillance is critical for prompt recognition and rapid control of outbreaks. Mosquito control measures can be used to prevent virus transmission until vaccination has taken effect.
Yellow fever vaccine is safe and highly effective. The protective effect (immunity) occurs within one week in 95% of people vaccinated. A single dose of vaccine provides protection for 10 years and probably for life.

Known Side Effects
Yellow fever vaccine generally has few side effects; fewer than 5% of vaccinees develop mild headache, muscle pain, or other minor symptoms 5 to 10 days after vaccination.
Reactions to yellow fever vaccine are generally mild. After vaccination, vaccinees have reported mild headaches, myalgia, low-grade fevers, or other minor symptoms 5–10 days after vaccination. In clinical trials, the incidence of mild adverse events has been ~25%.
Approximately 1% of vaccinees find it necessary to curtail regular activities. Immediate hypersensitivity reactions, characterized by rash, urticaria, or asthma or a combination of these, are uncommon (incidence <1>