NEW YORK (Reuters Health) Apr 01 - The varicella vaccine provides
adults with durable protection against serious varicella-zoster virus
disease, according to a report in the March 15th issue of Clinical
Infectious Diseases.
"The varicella vaccine was approved in 1995 for use in healthy
varicella-susceptible children and adults," Dr. Anne Gershon and
colleagues, from Columbia University, New York, note. They examined
the long-term immunity to varicella in 461 adults involved in
varicella vaccine trials from 1979 to 1999.
Forty of the vaccinees (9%) developed break-through chickenpox from
8 weeks to 11.8 years (mean, 3.3 years) after their last vaccination.
This included 19 of 89 vaccinees (21%) with household exposure to
chickenpox.
Among the 36 untreated vaccinees, the median number of skin lesions
was 20. The number of skin lesions did not change significantly with
time since vaccination, the team reports.
"Breakthrough chickenpox was mild, even among vaccinees who did not
have seroconversion or those recipients who lost detectable antibody,"
Dr. Gershon and colleagues write. "Lower varicella-zoster virus
antibody titers measured within 3 months of vaccination as well as at
the time of household exposure were associated with an increased risk
of breakthrough disease."
Clin Infect Dis 2002;34:774-779.
