Measles; Rubella; Tetanus; Vaccinations; Whooping cough
Chickenpox (caused by the varicella-zoster virus) is one of the most contagious childhood diseases. Nearly every unvaccinated child becomes infected with it. The affected child or adult may develop hundreds of itchy, fluid-filled blisters that burst and form crusts.
The infection rarely causes complications in healthy children, but it is not always harmless. Five out of every 1,000 children are hospitalized and, in rare cases, it can be fatal. Before the vaccination became widespread, chickenpox resulted in about 11,000 hospitalizations and 100 deaths a year.
Chickenpox can be especially severe in adults and very serious in anyone with a compromised immune system. In addition, the varicella virus (which persists in the body after the childhood disease is gone) erupts as a painful and distressing condition called herpes zoster (shingles) in about 20% of adults with a history of chickenpox. Chickenpox itself usually occurs only once, although a few cases of mild second infections, marked by the telltale rash, have been reported in older children years after their first infection.
A live-virus vaccine (Varivax) produces persistent immunity against chickenpox. Data show that the vaccine can prevent chickenpox or reduce the severity of the illness even if it is used within 3 days, and possibly up to 5 days, after exposure to the infection.
Recommendations for the Vaccine in Children. The vaccine against chickenpox is now recommended in the U.S. for all children between the ages of 12 months and adolescence who have not yet had chickenpox. Children are given 2 doses of the vaccine. The first dose is recommended at age 12-15 months. The second dose should be given at 4 - 6 years. However, doses can be as little as 28 days apart (note that the ideal minimum time for children under 13 years is 3 months). To date, more than 75% of children have been vaccinated.
Doctors recommend that the chickenpox vaccine be given at the same time as the measles-mumps-rubella (MMR) vaccine or that there is a delay of at least 1 month between the two vaccinations. (If the chickenpox vaccination is given within that 30-day period -- but not at the same time -- there is a higher risk for a breakthrough infection later on.)
A chickenpox vaccine is part of the routine immunization schedule. It is about 100% effective against moderate or severe illness, and 85 - 90% effective against mild chickenpox in children. Parents often express concern that the immunity from the vaccine might not last. The chickenpox vaccine, though, is the only routine vaccine that does not require a booster.
Recommendations for the Vaccine in Adults.
Some doctors suggest that every healthy adult without a known history of chickenpox, and who do not show immunity through testing be vaccinated. In general, however, the following adults should consider vaccinations:
As with other live-virus vaccines, the chickenpox vaccine is not recommended for the following people:
Discomfort at the Injection Site. About 20% of vaccine recipients have pain, swelling, or redness at the injection site.
Mild Rash and Risk of Transmission. The vaccine may produce a mild rash within about a month of the vaccination, which has been known to transmit chickenpox to others. Individuals who have recently been vaccinated should avoid close contact with anyone who might be susceptible to severe complications from chickenpox until the risk for a rash has passed.
Severe Side Effects. Between 1995 and 2001, 759 serious adverse effects were reported. Such events included seizures, pneumonia, anaphylactic reaction, encephalitis, Stevens-Johnson syndrome, neuropathy, herpes zoster, and blood abnormalities. Anecdotal reports have found a higher association of side effects when varicella vaccine is given at the same time as the measles, mumps, and rubella (MMR) vaccination. Because combined vaccinations are being developed, such effects should be closely studied.
There is intense debate over the long-term protection of the vaccine. However, any negative studies to date on long-term effectiveness simply raise the question of the need for booster or higher doses -- not the elimination of the vaccine altogether.
Long-Term Protection in Vaccinated Children. Most studies suggest that the vaccine is not wholly effective in up to 30% of vaccinated children. However, they also report if chickenpox occurs, more than 95% of the cases are mild. It is also usually less contagious. In such people, the infection appears to be caused by a wild virus, not a reactivation of the vaccine. The longer the interval since vaccination occurs, the higher the risk for a breakthrough infection.
Long-Term Protection in Vaccinated Adults. The protective effects for adults are even less clear.
Vaccine's Effect on Shingles. A primary concern is whether the vaccine protects against shingles later on, particularly in people who have breakthrough infections -- however mild. As more and more children get vaccinated, the actual protection of the vaccine and the implication of the breakthrough infection will become clearer.
[For more information, see In-Depth Report #82: Shingles and chickenpox (Varicella-zoster virus).]
In September 2005, the Food and Drug Administration approved a combination vaccine to protect against measles, mumps, rubella, and chickenpox. ProQuad, produced by Merck & Co., protects against all four infections with one injection. ProQuad is approved for use in children from 12 months to 12 years of age. However, due to manufacturing problems, the vaccine is in very limited supply at the time this report goes to print. In addition, the Food and Drug Administration (FDA) warns that children receiving ProQuad are at higher risk of developing febrile seizures, compared to children receiving the MMR and varicella vaccines separately.
American Academy of Pediatrics Committee on Infectious Diseases. Prevention and control of meningococcal disease: recommendations for use of meningococcal vaccines in pediatric patients. Pediatrics. 2005 Aug;116(2):496-505.
Centers for Disease Control and Prevention. Recommended Immunization Schedule for Ages 0 - 6 Years, United States, 2009.
Centers for Disease Control and Prevention. Recommended Immunization Schedule for Ages 7 - 18 Years, United States, 2009.
Centers for Disease Control and Prevention. Recommended Immunization Schedule for Adults, United States, 2009. Available online.
Centers for Disease Control and Prevention. Revised Recommendations of the Advisory Committee on Immunization Practices to Vaccinate All Persons Aged 11 - 18 Years with Meningococcal Conjugate Vaccine. Morbidity and Mortality Weekly Report. 2007:56(31);794-795.
Centers for Disease Control and Prevention. Notice to Readers: Recommendation from the Advisory Committee on Immunization Practices (ACIP) for Use of Quadrivalent Meningococcal Conjugate Vaccine (MCV4) in Children Aged 2 - 10 Years at Increased Risk for Invasive Meningococcal Disease. Morbidity and Mortality Weekly Report. 2007;56(48);1265-1266.
Centers for Disease Control and Prevention. Prevention of influenza: Recommendations of the Advisory Committee on Immunization Practices (ACIP), 2008. Morbidity and Mortality Weekly Report. 2008:57(No. RR-7).
Centers for Disease Control and Prevention. Update on Hib Vaccine Shortage. October 22, 2008. Available online.
Chaves SS, Gargiullo P, Zhang JX, Civen R, Guris D, Mascola L. Loss of vaccine-induced immunity to varicella over time. NEJM. March 15, 2007;356:1121-1129.
Garland SM, Hernandez-Avila M, Wheeler CM, Perez G, Harper DM, Leodolter S, et al. Quadrivalent vaccine against human papillomavirus to prevent anogenital diseases. NEJM. May 10, 2007;356:1928-1943.
GlaxoSmithKline. Boostrix Prescribing Information. December, 2008.
Grijalva CG, Nuorti JP, Arbogast PG, Martin SW, Edwards KM, Griffin MR. Decline in pneumonia admissions after routine childhood immunisation with pneumococcal conjugate vaccine in the USA: a time-series analysis. Lancet. April 7, 2007;369:1179-1186.
Poehling KA, Szilagyi PG, Crijalva CG, Martin SW, LaFleur B, Mitchel E, et al. Reduction of frequent otitis media and pressure-equalizing tube insertions in children after introduction of pneumococcal conjugate vaccine. Pediatrics. April 4, 2007;119:707-715.
US Food and Drug Administration. FDA Approves Expanded Uses for Gardasil to Include Preventing Certain Vulvar and Vaginal Cancers. September 12, 2008.
US Food and Drug Administration. FDA Approves New Vaccine to Prevent Gastroenteritis Caused by Rotavirus. April 3, 2008.
US Food and Drug Administration. Zostavax Questions and Answers. Available online. Last Accessed 3/12/2009.
World Health Organization. Immunization surveillance, assessment and monitoring -- United States of America (the) reported cases. Last Updated: December 18, 2008. Available online.
Zuckerman JN. Protective efficacy, immunotherapeutic potential, and safety of hepatitis B vaccines. J Med Virol. 2006 Feb;78(2):169-77.
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