chickenpox

Chickenpox vaccine is the best way to prevent chickenpox. Vaccination not only protects vaccinated persons, it also reduces the risk for exposure in the community for persons unable to be vaccinated because of illness or other conditions, including those who may be at greater risk for severe disease. While no vaccine is 100% effective in preventing disease, the chickenpox vaccine is very effective: about 8 to 9 of every 10 people who are vaccinated are completely protected from chickenpox. In addition, the vaccine almost always prevents against severe disease. If a vaccinated person does get chickenpox, it is usually a very mild case lasting only a few days and involving fewer skin lesions (usually less than 50), mild or no fever, and few other symptoms.

Should adults be tested before vaccination to see if they are already immune to chickenpox?
Currently, 90% of adults are immune to chickenpox because of having had the disease as children. If you have a history of chickenpox disease, you don't need testing or vaccination, unless you are working in an environment where your immune status must be documented (such as a hospital). If you are uncertain of your medical history, blood testing can be done to see if immunization is appropriate.

What side effects have been reported with this vaccine?
Possible side effects are generally mild and include redness, stiffness, and soreness at the injection site; such localized reactions occur in about 20% of children immunized. A small percentage of persons develop a mild rash, usually around the spot where the shot was given.

Can the vaccine protect you if you've already been exposed to chickenpox?
Yes, it is 70-100% effective if given within 72 hours of exposure.

Who should NOT receive the chickenpox vaccine?
Persons with weakened immune systems and those with life-threatening allergies to gelatin or the antibiotic neomycin should not receive this vaccine.

Pregnant women should not receive this vaccine, as the possible effects on fetal development are unknown. However, non-pregnant women of childbearing age who have never had the disease may be immunized against chickenpox to avoid contracting the disease while pregnant.

Can the vaccine cause chickenpox?
Because this vaccine is made from a live, but weakened, virus, about 1% of recipients develop a mild form of the disease, consisting of a limited rash, most often with only 5-6 blisters. Usually there is no fever. These persons are then safe from the more serious, naturally occurring form of the virus.