MenAfriVac as an Antitetanus Vaccine

Area of Science:

• Vaccinology
• Public Health
• Immunology

Background:

• The group A meningococcal conjugate vaccine, PsA-TT, utilizes tetanus toxoid (TT) as a carrier protein.
• Tetanus toxoid is known for its immunogenicity and ability to elicit a strong anti-TT response when used in other conjugate vaccines.

Purpose of the Study:

• To assess the immunogenicity of PsA-TT by measuring tetanus serologic responses in African populations.
• To evaluate the impact of PsA-TT mass immunization campaigns on neonatal tetanus incidence.

Main Methods:

• Clinical studies were conducted in Africa to evaluate PsA-TT's ability to generate tetanus serologic responses across various age groups (toddlers to adults).
• Data on neonatal tetanus incidence were reviewed in countries with and without PsA-TT campaigns to determine any correlation.
• The widespread acceptance of PsA-TT campaigns among 1- to 29-year-olds led to a significant number of women of reproductive age receiving the vaccine.

Main Results:

• PsA-TT vaccination elicited robust tetanus serologic responses in individuals aged 1 to 29 years, comparable to a TT booster dose.
• A 25% decrease in neonatal tetanus cases was observed in countries that had completed PsA-TT campaigns for the 1- to 29-year age group.

Conclusions:

• The findings suggest that PsA-TT campaigns may be contributing to improved community immunity against tetanus.
• These improvements in tetanus immunity are potentially impacting the incidence of neonatal tetanus in sub-Saharan Africa, although further definitive data are needed.