Pertussis in India: Vaccine-driven evolution, waning immunity, and the urgent need for Tdap boosters

Pertussis, once controlled by whole-cell pertussis (wP) vaccines, has resurged due to the shift to acellular pertussis (aP) vaccines, waning immunity, antigenic variation, and macrolide resistant Bordetella pertussis strains. Despite high DTwP coverage, India continues to face a significant burden and this review synthesizes current knowledge and advocates for enhanced surveillance, updated vaccination strategies, and targeted interventions to reduce the clinical and public health impact of pertussis.

Epidemiological data, genetic studies, and immunological insights from global and Indian contexts were reviewed. Information was obtained from PubMed, MEDLINE, Google Scholar, and WHONET. Particular attention was given to genomic surveillance, vaccine-induced antigenic shifts, and real-world outcomes of DTwP and aP vaccines.

Despite high DTwP vaccine coverage, India accounts for 26.5 % of global pertussis cases, driven by waning immunity, low booster uptake, and the spread of vaccine-escaped ptxP3 strains. The emergence of macrolide resistance further challenges disease control, with selective pressures influencing genetic shifts in B. pertussis. While wP vaccines provide long-lasting immunity, aP vaccines offer shorter protection and induce linked-epitope suppression, contributing to the resurgence of pertussis.

There is an urgent need for Tdap booster programs in adolescents and adults to address waning immunity and evolving strains. Strengthened genomic and immunological surveillance, alongside innovative vaccine formulations and delivery systems, are critical forsustainable pertussis control in India.