Effectiveness of pertussis vaccines for adolescents and adults: case-control study

• Published in: BMJ (Online) 2013-07, Vol.347 (7918), p.14-14
• Main Authors: Baxter, Roger, Bartlett, Joan, Rowhani-Rahbar, Ali, Fireman, Bruce, Klein, Nicola P
• Format: Article
• Language: English
• Subjects: Adolescent; Adolescents; Adult; Bordetella pertussis; California - epidemiology; Case control studies; Child; Childhood; Children; Humans; Incidence; Infections; Logistic Models; Medical records; Permanent paper; Pertussis; Pertussis Vaccine - therapeutic use; Polymerase chain reaction; Population control; Population studies; Teenagers; Vaccination; Vaccine efficacy; Vaccines; Whooping cough; Whooping Cough - epidemiology; Whooping Cough - prevention & control; Young Adult
• ISSN: 0959-8138; 1756-1833; 1756-1833
• DOI: 10.1136/bmj.f4249

Objective To assess the effectiveness of reduced acellular pertussis (Tdap) vaccines in adolescents and adults.Setting Kaiser Permanente Northern California.Design Case-control study.Participants All polymerase chain reaction (PCR) confirmed cases of pertussis in members aged 11 years and older from January 2006 to December 2011. We compared the Tdap vaccination status of PCR positive cases with two control groups: people testing negative for pertussis by PCR and closely matched people from the general Kaiser Permanente Northern California population.Main outcome measure PCR confirmed pertussis. The association of Tdap vaccination with the odds of pertussis infection was estimated by conditional logistic regression, with adjustment for calendar time, pertussis vaccine type received in early childhood, age, sex, race or ethnic group, and medical clinic. We calculated Tdap vaccine effectiveness as 1 minus the adjusted odds ratio.Results The study population included 668 PCR positive cases, 10 098 PCR negative controls, and 21 599 Kaiser Permanente Northern California matched controls. Tdap vaccination rates were 24.0% in PCR positive cases and 31.9% in PCR negative controls (P