Epidemiological consequences of an ineffective Bordetella pertussis vaccine

TL;DR

This study uses a dynamic transmission model to analyze how an ineffective B. pertussis vaccine impacts disease incidence, surveillance accuracy, and vaccination strategies, highlighting challenges in controlling whooping cough.

Contribution

It demonstrates that an ineffective vaccine can explain rising incidence and questions the effectiveness of cocooning strategies, informing vaccination policy.

Findings

Ineffective vaccine can explain increased disease incidence.

Asymptomatic infections bias surveillance data.

Cocooning strategy may be ineffective.

Abstract

The recent increase in Bordetella pertussis incidence (whooping cough) presents a challenge to global health. Recent studies have called into question the effectiveness of acellular B. pertussis vaccination in reducing transmission. Here we examine the epidemiological consequences of an ineffective B. pertussis vaccine. Using a dynamic transmission model, we find that: 1) an ineffective vaccine can account for the observed increase in B. pertussis incidence; 2) asymptomatic infections can bias surveillance and upset situational awareness of B. pertussis; and 3) vaccinating individuals in close contact with infants too young to receive vaccine (so called "cocooning" unvaccinated children) may be ineffective. Our results have important implications for B. pertussis vaccination policy and paint a complicated picture for achieving herd immunity and possible B. pertussis eradication.