Varicella vaccine (VARIVAX) in healthy children and adolescents: results from clinical trials, 1987 to 1989

A total of 3303 healthy children and adolescents, aged 12 months to 17 years, were vaccinated with one of five production lots of a live attenuated varicella vaccine (VARIVAX) containing 1000 to 1625 plaque-forming units per dose. The vaccine was generally well tolerated. Ninety-six percent (2381/2475) of vaccinees responded to vaccination by producing antibody as measured by a glycoprotein-based enzyme-linked immunosorbent assay; 99% (569/576) of those tested maintained antibody at 1 year following vaccination. The incidence of varicella following household exposure in vaccinees was approximately 12%; household contact historically results in 87% infection. Nearly all of the vaccinees who had varicella after vaccination had a clinically modified disease.