Protective Effect of Contemporary Pertussis Vaccines: A Systematic Review and Meta analysis.
BACKGROUND Acellular pertussis (aP) and whole cell (wP) pertussis vaccines are presumed to have similar short term <3 years after completion of the primary series) efficacy. However, vaccine effect varies between individual pertussis vaccine formulations, and many originally studied formulations are now unavailable. An updated analysis of the short term protective effect of pertussis vaccines limited to formulations currently on the market in developed countries is needed. METHODS We conducted a systematic review and meta analysis of published studies that evaluated pertussis vaccine efficacy or effectiveness within 3 years after completion >3 doses) of a primary series of a currently available aP or wP vaccine formulation. The primary outcome was based on the World Health Organization (WHO) clinical case definitions for pertussis. Study quality was assessed using the approach developed by the Child Health Epidemiology Research Group. We determined overall effect sizes using random effects meta analyses, stratified by vaccine (aP or wP) and study (efficacy or effectiveness) type. RESULTS Meta analysis of 2 aP vaccine efficacy studies (assessing the 3 component GlaxoSmithKline and 5 component Sanofi Pasteur formulations) yielded an overall aP vaccine efficacy of 84% (95% confidence interval [CI] 81% 87% Meta analysis of 3 wP vaccine effectiveness studies (assessing the Behringwerke, Pasteur/Merieux, and SmithKline Beecham formulations) yielded an overall wP vaccine effectiveness of 94% (95% CI, 88% 97% (bothI(2) 0% CONCLUSIONS Although all contemporary aP and wP formulations protect against pertussis disease, in this meta analysis the point estimate for short term protective effect against WHO defined pertussis in young children was lower for currently available aP vaccines than wP vaccines.
Clinical infectious diseases an official publication of the Infectious Diseases Society of America