Long-term human serum antibody responses after immunization with whole-cell pertussis vaccine in France

Area of Science:

• Immunology
• Infectious Diseases
• Vaccinology

Background:

• Pertussis, or whooping cough, remains a public health concern globally.
• Whole-cell pertussis vaccines are widely used but their long-term efficacy is debated.
• Understanding antibody dynamics post-vaccination is crucial for assessing immunity.

Purpose of the Study:

• To evaluate pertussis serology in children after whole-cell vaccination.
• To investigate antibody responses to key pertussis antigens.
• To assess the duration of immunity and potential for secondary infections.

Main Methods:

• Serological testing of 360 children post-vaccination using immunoblot and agglutination assays.
• Detection of antibodies against pertussis toxin, filamentous hemagglutinin, adenylate cyclase-hemolysin, and pertactin.
• Quantification of anti-agglutinogen antibodies.

Main Results:

• Antibodies to pertussis toxin, pertactin, and agglutinogens showed rapid decline followed by secondary increases, suggesting infection.
• Anti-filamentous hemagglutinin antibodies persisted, while anti-adenylate cyclase-hemolysin antibodies increased continuously.
• These patterns indicate potential cross-reactivity or exposure to Bordetella isolates.

Conclusions:

• Unrecognized pertussis infections are common in France, even with high vaccination rates.
• Vaccinated children may lose immunity and become susceptible to pertussis more than six years after their last vaccination.
• The findings highlight the need for ongoing surveillance and potentially updated vaccination strategies.