AIM: To evaluate the risk factors for breakthrough varicella in a follow up study of a cohort of 181 healthy children immunised when aged 9-24 months with a reformulated Oka strain varicella vaccine (SmithKline Beecham Biologicals/Oka). DESIGN: The children were randomised in a double blind manner into one of four groups to receive one of two production lot vaccine batches, at two different titres (high titre, 10(3.9) and 10(4.0) plaque forming units (pfu); low titre (heat exposed), 10(2.7) and 10(2.8) pfu). The overall seroconversion rate after immunisation was 99%. RESULTS:One hundred and sixty-eight patients were available for review after a mean (SD) follow up of 35 (9) months after vaccination. Multivariate analysis indicated that risk factors for breakthrough varicella were household contact with varicella (adjusted odds ratio (OR), 19.89; 95% confidence interval (CI), 18.39 to 21.39), vaccination age of < or = 14 months (adjusted OR, 2.30; 95% CI, 1.69 to 2.90), and receiving low titre (10(2.7) pfu) vaccine (adjusted OR, 2.13; 95% CI, 1.54 to 2.73). All children who developed breakthrough varicella, had a modified varicella illness, except for three, all of whom had received low titre vaccine. CONCLUSION: The identification of young immunisation age (< or = 14 months) and low titre vaccine as risk factors for breakthrough varicella have important implications for the implementation of varicella vaccination programmes in healthy children.
RCT Entities:
AIM: To evaluate the risk factors for breakthrough varicella in a follow up study of a cohort of 181 healthy children immunised when aged 9-24 months with a reformulated Oka strain varicella vaccine (SmithKline Beecham Biologicals/Oka). DESIGN: The children were randomised in a double blind manner into one of four groups to receive one of two production lot vaccine batches, at two different titres (high titre, 10(3.9) and 10(4.0) plaque forming units (pfu); low titre (heat exposed), 10(2.7) and 10(2.8) pfu). The overall seroconversion rate after immunisation was 99%. RESULTS: One hundred and sixty-eight patients were available for review after a mean (SD) follow up of 35 (9) months after vaccination. Multivariate analysis indicated that risk factors for breakthrough varicella were household contact with varicella (adjusted odds ratio (OR), 19.89; 95% confidence interval (CI), 18.39 to 21.39), vaccination age of < or = 14 months (adjusted OR, 2.30; 95% CI, 1.69 to 2.90), and receiving low titre (10(2.7) pfu) vaccine (adjusted OR, 2.13; 95% CI, 1.54 to 2.73). All children who developed breakthrough varicella, had a modified varicella illness, except for three, all of whom had received low titre vaccine. CONCLUSION: The identification of young immunisation age (< or = 14 months) and low titre vaccine as risk factors for breakthrough varicella have important implications for the implementation of varicella vaccination programmes in healthy children.
Authors: E Tynell; E Aurelius; A Brandell; I Julander; M Wood; Q Y Yao; A Rickinson; B Akerlund; J Andersson Journal: J Infect Dis Date: 1996-08 Impact factor: 5.226
Authors: N J Webb; M M Fitzpatrick; D A Hughes; T J Brocklebank; B A Judd; M A Lewis; R J Postlethwaite; P A Smith; G Corbitt Journal: Arch Dis Child Date: 2000-02 Impact factor: 3.791
Authors: Paolo Bonanni; Anne Gershon; Michael Gershon; Andrea Kulcsár; Vassiliki Papaevangelou; Bernard Rentier; Catherine Sadzot-Delvaux; Vytautas Usonis; Timo Vesikari; Catherine Weil-Olivier; Peter de Winter; Peter Wutzler Journal: Pediatr Infect Dis J Date: 2013-07 Impact factor: 2.129