Should Japanese athletes undergo booster vaccination for pertussis?

Pertussis, a highly contagious respiratory infection caused by Bordetella pertussis, has demonstrated a global resurgence in the post-COVID-19 era, with the emergence of macrolide-resistant strains. In Japan, the routine immunization schedule for pertussis remains limited compared with international standards, leaving young populations under-immunized and at elevated risk of infection. Despite international recommendations for booster vaccinations during adolescence, Japan currently provides only a four-dose primary series during infancy, without subsequent boosters. This immunization gap possibly increases the vulnerability of Japanese athletes to pertussis. Persistent cough can significantly impair athletic performance for weeks to months, posing substantial challenges to professional sports teams. To protect athletes' health and performance capacity and prevent team-wide outbreaks, it is imperative to consider pertussis booster immunizations in Japan, especially for elite athletes. However, DTaP (diphtheria, tetanus, and acellular pertussis) (TRIBIKⓇ) is the only available vaccine in Japan, which contains higher antigen concentrations than the internationally used Tdap (tetanus, diphtheria, pertussis) vaccines (ADACEL™ and BOOSTRIXⓇ): the antigen contents of pertussis toxin, filamentous hemagglutinin, and diphtheria toxin in TRIBIKⓇ, ADACEL™, and BOOSTRIXⓇ are 23.5 µg/23.5 µg/≤15 µg, 2.5 µg/5 µg/2 µg, and 8 µg/8 µg/2.5 µg, respectively. These differences result in more severe local adverse effects in vaccinees and would complicate booster strategies in Japan. Aligning Japan's immunization policies with international practices represents a critical step toward ensuring individual health and public safety in increasingly globalized sports environments.