Backgrounds:

Concomitant administration of meningococcal (Men), tetanus, diphtheria, pertussis (Tdap) and human papillomavirus (HPV) vaccines could increase compliance to adolescents’ immunization schedules.

Methods

A phase 4 study of 801 healthy participants aged 11–18 years investigated the immunogenicity and safety of a quadrivalent Men conjugate vaccine (MenACWY-CRM) co-administered with Tdap and quadrivalent HPV (HPV-4) vaccines (NCT01424644). Participants were randomised (1:1) to receive either MenACWY-CRM (MenACWY group) or placebo (placebo group), co-administered with Tdap and HPV4, with two additional HPV4 doses, 2 and 6 months after the first. Antibody responses to Men A, C, W and Y serogroups, Tdap antigens and HPV-6, -11, -16 and -18 were assessed at baseline and one month post-vaccination. Safety was monitored throughout the study.

Results:

At one month post-vaccination, 77%, 84%, 95% and 86% of participants in the MenACWY group achieved human complement serum bactericidal activity titres ≥8 against Men A, C, W and Y, respectively, and 95% and 99% had seroprotective antibody levels (≥1.0 IU/mL) against diphtheria and tetanus toxoids, respectively, compared with 82% and 98% in the placebo group. Seroconversion rates against HPV types ranged between 98.0% (HPV-6) and 99.7% (HPV-11 and HPV-18) for participants in the MenACWY group and between 99.0% (HPV-11 and HPV-16) and 99.7% (HPV-6 and HPV-18) in the placebo group. Predetermined non-inferiority criteria for immunological responses against all Tdap antigens and HPV types were met, thus fulfilling the co-primary study endpoints. No safety concerns with co-administration of the three vaccines were identified.

Conclusions/Learning Points:

Integrated results from this phase 4 study support concomitant administration of MenACWY-CRM, Tdap and HPV-4 vaccines as an immunisation practice for adolescents.

Funding: GlaxoSmithKline Biologicals SA.

Acknowledgements: Business & Decision Life Sciences (Coordinator: Julien Doornaert).