Pertussis incidence in children under 1 year old and relation with maternal vaccination in Brazil, 2008-2018

Abstract

Objetive:

To analyze the impact of maternal vaccination coverage with diphtheria-tetanus-acellular pertussis (Tdap) adsorbed vaccine for adults on pertussis incidence in children under 1 year old in Brazil from 2008 to 2018.

Methods:

This was a descriptive ecological temporal trend study using data from surveillance systems managed by the Brazilian National Health System Information Technology Department (DATASUS). Incidence rates and incidence rate ratios (IRR) were calculated with respective 95% confidence intervals (95%CI).

Results:

There were 20,650 pertussis cases in the study period. In the post-vaccination period there was a 26.6% reduction (IRR = 0.73; 95%CI 0.66;0.82) in pertussis incidence among children aged from 3 months up to but not including 1 year old, and a 63.6% reduction (IRR = 0.36; 95%CI 0.15;0.58) among children from birth to 2 months old.

Conclusion:

The increase in maternal Tdap vaccination coverage coincided with a reduction in pertussis incidence, especially in the birth to two-month-old age group.

Keywords:
Whooping Cough; Immunization Schedule; Child; Primary Health Care; Observational Study