The Food and Drug Administration approved the long-awaited chickenpox vaccine Friday, the nation's first protection for the 4 million Americans who get the disease every year.
Merck & Co.'s Varivax vaccine is 70 percent to 90 percent effective at preventing any chickenpox lesions, the FDA said. Those stricken by the virus anyway have much milder cases.The approval comes at an opportune time - chickenpox increases in the spring. Merck says its vaccine will be available in doctors' offices within eight weeks.
"I'm ecstatic," said Rebecca Cole, a North Carolina mother who has pushed FDA to approve the vaccine for almost seven years, after her son died of chickenpox. "I think we're going to see an end to chickenpox as we know it."
Chickenpox typically is a nuisance disease, keeping bump-covered students out of school and their parents out of work for about a week. Ninety percent of cases are in children.
But it can be deadly, killing up to 90 people a year and hospitalizing 9,300. It is most dangerous to infants, adults and people with immune problems, either from diseases or from certain drugs that depress immunity.
The FDA recommended a single injection of Varivax for children ages 12 months to 12 years. Teen-agers and adults need two shots, four to eight weeks apart.
The shots can be given at the same time as the measles, mumps and rubella vaccines, saving an additional doctor visit. Side effects include redness, hardness and swelling at the injection site and some mild fatigue and nausea.
Nobody knows for sure just how long Varivax protects and whether people will need booster shots as they age. Merck will study tens of thousands of vaccinated patients from a Durham, N.C., day-care center and a California health maintenance organization to settle the issue.
Another unanswered question: How Varivax will affect shingles, a very painful disease among the elderly that is caused by the chickenpox virus that hibernates inside the body for decades. The FDA said there is no indication Varivax will increase shingles, but asked Merck to study that as well.
The government has predicted that Varivax won't make chickenpox disappear.