A major outbreak of whooping cough, or pertussis, occurred in 2012 in the U.K, with nearly 10 000 laboratory-confirmed cases and 14 infant deaths attributed to pertussis. A worldwide resurgence of pertussis has been linked to switch to the use of acellular pertussis vaccines and the evolution of B. pertussis away from vaccine-mediated immunity. We have conducted genomic analyses of multiple strains from the UK outbreak. We show that the UK outbreak was polyclonal in nature, caused by multiple distinct but closely related strains. Importantly, we demonstrate that acellular vaccine antigen encoding genes are evolving at higher rates than other surface protein encoding genes. This was true even prior to the introduction of pertussisvaccines, but has become more pronounced since the introduction of the current acellular vaccines. The fast evolution of vaccine antigen genes has serious consequences for the ability of current vaccines to continue to control pertussis.
Journal:J Infect Dis. 2014