Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SATURDAY, March 18, 1995 TAG: 9503210051
SECTION: NATIONAL/INTERNATIONAL PAGE: A-1 EDITION: METRO
SOURCE: Los Angeles Times
DATELINE: WASHINGTON LENGTH: Medium
The highly contagious disease, always a nuisance and sometimes life-threatening, afflicts nearly 4 million people annually, most of them children. Typically, it is a benign disease in children, but can be quite severe in teen-agers and adults or when unforeseen complications result.
``This vaccine has been studied in approximately 11,000 individuals and we expect it to be 70 percent to 90 percent effective in preventing chickenpox,'' Food and Drug Administration Commissioner David Kessler said.
The vaccine, which is manufactured by Merck and Co. of Whitehouse Station, N.J., is made from a live but weakened form of the varicella virus - a member of the Herpes family - which causes chickenpox.
The vaccine, which will be marketed under the trade name Varivax, will be available to pediatricians within eight weeks, according to the company. It will cost $39 for each dose, company officials said.
The company has recommended a single injection for children 12 months to 12 years of age, and two injections four to eight weeks apart in those age 13 and older, based on its studies of the vaccine in 9,454 children and 1,648 adolescents and adults. The vaccine is not recommended for those who have had chickenpox because they have lifelong immunity from the disease.
The national Centers for Disease Control, however, is expected to issue official recommendations this spring on the timetable for including chickenpox in the childhood immunization schedule.
The FDA said that the chickenpox vaccination can be administered at the same time as the combination shot for measles, mumps and rubella (German measles) without any ill effects, meaning that both shots can be given during a single visit to the pediatrician.
The vaccine has been studied for more than a decade.
``This is a vaccine that is going to go potentially into every young child in the country,'' said Kathryn Zoon, director of the FDA's center for biologics evaluation and research.
Among the lingering concerns was the possibility of waning immunity over time, raising the potential that individuals immunized as children could become vulnerable to chickenpox later in life, when the disease can be far more serious.
Also, experts wanted to study the extent and severity of so-called ``breakthrough'' cases, which is when vaccinated patients contract the disease after exposure to naturally occurring chickenpox.
As with natural chickenpox, the virus remains in the body's nerve cells for life, meaning that it could reactivate later as zoster (shingles), an especially painful skin condition, or as some other nervous system disorder.
But Dr. Philip Krause of the FDA's biologics center said that studies thus far have shown that these kinds of problems ``are not likely to happen.'' The manufacturer will conduct strict post-market surveillance in coming years to ensure that any such problems are promptly identified, he said.
by CNB