Chickenpox immunization for adults

General information
The U.S. Food and Drug Administration (FDA) approved Varivax, the first chickenpox vaccine, in March 1995. The vaccine is considered a live vaccine because it contains a weakened form of the virus that causes chickenpox, the varicella zoster virus.

Recommendations
The vaccine is recommended for all healthy adults who haven't had chickenpox, especially:
nonpregnant women of childbearing age who will avoid pregnancy for at least one month (The manufacturer recommends waiting three months to become pregnant, however.)
health care workers
family members of people who have weak immune systems
those living in households with children
teachers of young children and child care workers
residents and staff in institutional settings, including prisons
college students or military personnel
international travelers
unvaccinated persons exposed to chickenpox (Receiving the vaccine within three to five days of exposure may prevent chickenpox or decrease its severity.)

Dose
Anyone age 13 or older requires two doses, with the second dose given four to eight weeks after the first.

Effectiveness/booster
The two doses are up to 95 percent effective in preventing chickenpox. The few people who develop chickenpox despite receiving the vaccine usually have only a mild illness. The length of protection is uncertain. A booster is not recommended at this time.

Side effects
Side effects are uncommon. When they occur, they're usually mild and include pain, tenderness, redness or swelling at the injection site and a fever of 102°F or higher. (Use acetaminophen, not aspirin or aspirin-containing products, for pain or fever in children age 19 or younger for six weeks after the vaccine due to the risk of Reye's syndrome, a rare but serious illness involving the brain and liver following a viral infection.) Acetaminophen is the only pain and fever medication recommended for this age group.
A mild chickenpox-like rash may develop at the injection site or elsewhere five to 26 days after the vaccine that rarely can spread the chickenpox virus to others. An allergic reaction, pneumonia, blood clotting problems and neurological reactions may occur, but these side effects are extremely rare.

As with the chickenpox infection, people who receive the vaccine may later develop shingles (an illness caused by the same virus that causes chickenpox). However, this occurs less frequently than with the natural infection, and the symptoms tend to be mild and uncomplicated.


Who should wait to receive the vaccine
The vaccine may be postponed if you have a moderate to severe acute illness or if you've received a blood product containing an antibody (such platelets, a blood transfusion or an immune globulin) within the last three to 11 months (depending on which product is given) or will receive such a product in the next two weeks.

Who should not receive the vaccine
You should not receive the vaccine if you've had a severe allergic reaction to a prior dose of the vaccine, gelatin or the antibacterial drug neomycin. It's also not recommended if you have untreated active tuberculosis. Your doctor may also caution against the vaccine if your immune system is not functioning normally.

Pregnancy-specific information
Do not have this vaccine if you're pregnant, and avoid pregnancy for one month after receiving the vaccine. (Vaccine manufacturer recommends waiting three months before becoming pregnant.)
Since March 1995, when the vaccine was approved for use in the United States, there have been no reported birth defects in babies whose mothers received the vaccine during pregnancy. In conjunction with the vaccine manufacturer, experts at the Centers for Disease Control and Prevention have developed a registry for monitoring outcomes of chickenpox vaccinations received during pregnancy. For more information, call (800) 986-8999.