European Journal of Pediatrics

, Volume 155, Issue 8, pp 706–711

Use of a reformulated Oka strain varicella vaccine (SmithKline Beecham Biologicals/Oka) in healthy children

Authors

  • A. Y. S. Tan
    • Department of PaediatricsNational University of Singapore
  • C. J. Connett
    • Department of PaediatricsNational University of Singapore
  • G. J. Connett
    • Department of PaediatricsNational University of Singapore
  • S. C. Quek
    • Department of PaediatricsNational University of Singapore
  • H. K. Yap
    • Department of PaediatricsNational University of Singapore
  • F. Meurice
    • SmithKline Beecham Biologicals
  • B. W. Lee
    • Department of PaediatricsNational University of Singapore
Preventive Pediatrics And Epidemiology

DOI: 10.1007/BF01957158

Cite this article as:
Tan, A.Y.S., Connett, C.J., Connett, G.J. et al. Eur J Pediatr (1996) 155: 706. doi:10.1007/BF01957158

Abstract

The first live-attenuated Oka strain varicella vaccines needed to be stored at −20°C. Reformulation of this vaccine by SmithKline Beecham Biologicals has provided a vaccine shelf life of up to 2 years when stored at +2°C to +8°C. In this study the immunogenicity and reactogenicity of two different production lots of this reformulated vaccine at two different titres each, which corresponded to the release and expected expiry titres, were evaluated. A double-blind randomised clinical trial was conducted in healthy children aged from 9 to 24 months. Immunogenicity was assessed by the measurement of varicella specific antibodies in paired serum samples taken before and from 35 to 63 days post vaccination. Reactogenicity was assessed by the evaluation of any untoward reactions occurring up to 42 days post vaccination. In order to assess protective efficacy, parents of these subjects were contacted approximately 6 months after completion of the trial. One hundred and ninety-one subjects were recruited into the study. Of the 181 initially seronegative subjects who completed the trial according to the protocol, 179 showed seroconversion (98.9%). Reactions to the vaccine were minor and observed in 46/191 (24%) of subjects. Rashes were present in 19, fever in 22, and both fever and rashes in 5. Rashes were mainly maculo-papular in nature but were vesicular in 6. Febrile reactions were shortlived. After a 6-month follow up period, attenuated varicella with minor clinical symptoms was diagnosed in 6/52 vacinees who had close contact with natural varicella (attack rate=11.5%).

Key words

Varicella vaccineChildrenSeroconversionImmunogenicityReactogenicity

Abbreviation

pfu

plaque-forming unit

Copyright information

© Springer-Verlag 1996