Chickenpox is a commonplace viral illness. But there are rare cases of serious disease, especially in immunodeficient patients, adults, or pregnant women (and the foetus). Evaluation among immunodeficient children is very limited, and there is little data on pregnant women. In patients with normal immunity (especially children), the chickenpox vaccine leads to a satisfactory production of antibodies. Chickenpox vaccines are attenuated live vaccines which expose the subject to local reactions at the point of injection, and systemic adverse effects that are harmless. But they can cause serious chickenpox in the case of undetected immune deficiency. As a precaution, vaccination should be avoided in pregnant woman. The usual mildness of chickenpox in childhood and the fact that vaccinating children is likely to make them susceptible as adults, in whom the disease is more serious, militate against mass vaccination of children. Vaccination should be restricted to certain groups of non-immunised, non immunodeficient adults, such as health workers and nursery staff, who are likely to spread chickenpox to those in contact with an immunodeficient person. This includes adults with no known chickenpox history and who have had very recent contact with a case of chickenpox (the vaccination seems to be effective when it is given within 2 or 3 days after exposure to the virus), and to children awaiting transplants.
©Prescrire March 2005
Source:
"Vaccins varicelle : une balance bénéfices-risques favorable pour certains sujets" Rev Prescrire 2005 ; 25 (259) : 167-174.
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