The chickenpox vaccine, also known as the varicella vaccine, is used to prevent chickenpox. As with any other vaccine, it is not 100 percent effective at preventing the disease; however, vaccinated people who develop chickenpox usually develop a milder case than unvaccinated people.
For chickenpox prevention, the vaccine should be used in the following groups of people:
- All children between 12 and 18 months of age should have one dose of chickenpox vaccine.
- Children who have had chickenpox do not need the vaccine. No tests need to be administered to determine immune status -- a parent's recollection of the disease is considered a reliable measure of previous infection and therefore immunity.
- Children between 19 months and 13 years old, who have not had chickenpox, should be vaccinated with a single dose.
- People 13 and older who have not had chickenpox should get two doses of the vaccine 4 to 8 weeks apart.
The chickenpox vaccine may be given at the same time as other vaccines.
No vaccine is 100 percent effective in preventing disease. For the chickenpox vaccine, about 8 to 9 out of every 10 people who are vaccinated are completely protected from chickenpox. The vaccine almost always prevents against severe disease. If a vaccinated person does get chickenpox, it is usually a very mild case with fewer skin lesions (usually less than 50) lasting only a few days, no fever or a low fever, and few other symptoms.