Thursday 27 August 2015

What is the MMR vaccine?


Benefits of Vaccination

The combined MMR vaccine protects children and adults against measles, mumps, and rubella all together. Before the vaccine was developed, these highly contagious diseases were prevalent, and virtually all children became infected at some point. In the 1960s vaccines were developed for each disease individually, and in 1971 the separate vaccines were combined into the MMR vaccine. In 1993 doctors began recommending a booster shot to increase children's protection against the diseases. In 2005 a version known as MMRV was made available that combined the standard MMR vaccine with the vaccine for chickenpox, or varicella.


The vaccination program was highly successful at reducing cases of all three diseases in the United States. Outbreaks of measles, mumps, and rubella only typically continue to occur in areas with clusters of nonimmunized children, such as in religious communities that avoid immunization or in families in which a parent or parents fear that the MMR vaccine has harmful side effects and has a link to autism.





MMR vaccine and autism. A controversial study published in 1998 by the journal The Lancet suggested a link between the MMR vaccine and rising rates of autism. The article soon led to widespread fear among parents of the safety of the vaccine, and some parents refused the vaccine for their children. Pockets of nonimmunized children contributed to renewed outbreaks of measles, mumps, and rubella in the United States and in the United Kingdom and other European countries. The original study, however, was flawed, and The Lancet officially retracted the report in February 2010. The article, authored by the discredited British researcher Andrew Wakefield and coauthors, had erroneous conclusions. Additional research attempting to replicate Wakefield’s findings did not support his results. Rather, further study found no evidence of a link between the MMR vaccine and autism, supporting the safety of vaccination. Still, the negative publicity generated by the report helped sustain a vocal minority of antivaccination advocates despite widespread scientific consensus that failing to vaccinate children has a negative effect on public health.



Side effects. The MMR vaccine is associated with mild side effects that include fever, mild rash, and swollen glands. Less common side effects include seizure and temporary joint pain. Rarely, allergic reactions or serious side effects such as deafness, long-term seizures, and brain damage may occur.




Impact

The MMR vaccine has reduced the incidence of measles, mumps, and rubella by more than 99 percent according to the Centers for Disease Control and Prevention. The success of the vaccine in dramatically reducing the spread of these diseases has enabled the U.S. government’s Childhood Immunization Initiative to set a goal of eradicating native measles, mumps, and rubella in the United States. This goal acknowledges that the viruses may be brought to the United States by people who were infected in other countries.


The vaccine leads to lifelong immunity. Children receive the dose between twelve and fifteen months of age and get a booster shot between four and six years of age. After two doses, the vaccine protects 99 percent of the children immunized. In some cases adults may be recommended to receive the vaccine as well.




Bibliography


Centers for Disease Control and Prevention. “Vaccine Safety: Measles, Mumps, and Rubella (MMR) Vaccine.” Available at http://www.cdc.gov/vaccinesafety.



Editors of The Lancet. “Retraction: Ileal-Lymphoid-Nodular Hyperplasia, Non-specific Colitis, and Pervasive Developmental Disorder in Children.” The Lancet 375 (2010): 445.



Griffin, Diane E., and Michael B. A. Oldstone, eds. Measles: History and Basic Biology. New York: Springer, 2009.



Hawkins, Trisha. Everything You Need to Know About Measles and Rubella. New York: Rosen, 2001.



Institute of Medicine. Immunization Safety Review: Vaccines and Autism. Washington, D.C.: National Academies Press, 2004.



"Measles: Questions and Answers." Immunization Action Coalition. Immunization Action Coalition, n.d. Web. 23 Dec. 2015.



"MMR Vaccine Does Not Cause Autism." Immunization Action Coalition. Immunization Action Coalition, n.d. Web. 23 Dec. 2015.

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