Safety and
immunogenicity of gelatin-free varicella vaccine in epidemiological and
serological studies in Japan.
Ozaki T, Nishimura N,
Muto T, Sugata K, Kawabe S, Goto K, Koyama K, Fujita H, Takahashi Y,
Akiyama M.
Department of Pediatrics, Showa Hospital, Konan,
Aichi 483-8703, Japan. sh-t-oz@showa.jaaikosei.or.jp
Following
gelatin-containing varicella vaccine (1994-1999: 1,410,000 distributed
doses), 28 serious anaphylactic reactions and 139 non-serious allergic
reactions were reported, with no serious and only five non-serious
reactions following gelatin-free vaccine (1999-2000: 1,300,000
distributed doses). All nine sera available from children with serious
reactions tested positive for gelatin-specific IgE, whereas 55 of the 70
available from those with non-serious reactions were positive, with one
false positive. There was no correlation between gelatin-specific IgE
antibody titers and severity of allergic reaction. Post-immunization
anti-varicella antibody titers were comparable for both gelatin-free and
gelatin-containing vaccine groups. The new gelatin-free varicella
vaccine is thought to be safe, with similar immunogenicity to the
earlier gelatin-containing vaccine.