Sustained Effectiveness of the Maternal Pertussis Immunization Program in England 3 Years Following Introduction

Area of Science:

• Immunology
• Vaccinology
• Pediatrics

Background:

• Infant pertussis poses a significant health risk.
• Maternal immunization programs aim to protect infants before they can be vaccinated.
• The introduction of maternal pertussis vaccination in England in 2012 aimed to reduce infant disease.

Purpose of the Study:

• To evaluate the sustained effectiveness of maternal immunization against infant pertussis.
• To assess vaccine effectiveness against laboratory-confirmed pertussis and infant deaths.
• To determine the duration and extent of additional protection provided by maternal vaccination.

Main Methods:

• Analysis of pertussis surveillance data following the introduction of maternal immunization.
• Calculation of vaccine effectiveness against laboratory-confirmed pertussis in infants.
• Estimation of vaccine effectiveness against infant deaths.

Main Results:

• Maternal immunization demonstrated sustained vaccine effectiveness of over 90% against infant pertussis.
• Disease incidence in infants under 3 months remained low, despite high circulation in older individuals.
• Vaccine effectiveness against infant deaths was estimated at 95%.
• Additional protection from maternal vaccination was observed after the first infant dose but not after the third.
• No increased risk of disease was detected in infants whose mothers received the vaccine.

Conclusions:

• Maternal immunization is a highly effective strategy for preventing infant pertussis.
• The program has shown sustained effectiveness and a significant reduction in infant mortality.
• Maternal vaccination provides crucial early protection, with waning additional benefit after infant primary series completion.