Pertussis in Mexico from 2000 to 2019: A real-world study of incidence, vaccination coverage, and vaccine effectiveness

Abstract

BackgroundThe national immunization program in Mexico includes a 3-dose primary series of pertussis vaccine and a toddler booster dose. In Mexico, whole-cell pertussis vaccines (wP) were switched in 2007 to acellular pertussis vaccines (aP). MethodsThis retrospective study using Mexican National Databases of Health and population surveillance (2000–2019) assessed the incidence of pertussis, infant pertussis vaccination coverage, and vaccine effectiveness (VE) against clinically-diagnosed and/or laboratory-confirmed pertussis in children aged 6.5–18.5 or 24.5 months for the primary series, and children aged 18.5 or 24.5–48.5 months for the toddler booster. ResultsThe incidence of pertussis sharply increased in 2012 and was highest in 2012, 2015, and 2016 (0.84–0.94/100,000 person-years). Coverage was highest for the first dose in the primary series, decreasing for each subsequent dose. The VE against notified pertussis was 96.4% (95% CI: 94.7, 97.6) for the first three doses of wP vaccine (2000–2007) and 95.7% (95% CI: 95.1, 96.2) for the first three doses of aP vaccine (2008–2019). ConclusionsOur findings suggested high levels of vaccine effectiveness overall were achieved for the aP and wP vaccines in Mexico between 2000 and 2019.