Abstract
We previously reported higher anti-HPV-16 and -18 immune responses induced by HPV-16/18 vaccine compared with HPV-6/11/16/18 vaccine at Month 7 (one month after completion of full vaccination series) in women aged 18-45 y in an observer-blind study NCT00423046; the differences of immune response magnitudes were maintained up to Month 24. Here we report follow-up data through Month 48. At Month 48, in according-to-protocol cohort for immunogenicity (seronegative and DNA-negative for HPV type analyzed at baseline), geometric mean titers of serum neutralizing antibodies were 2.0- to 5.2-fold higher (HPV-16) and 8.6- to 12.8-fold higher (HPV-18) in HPV-16/18 vaccine group than in HPV-6/11/16/18 vaccine group. The majority of women in both vaccine groups remained seropositive for HPV-16. The same trend was observed for HPV-18 in HPV-16/18 vaccine group; however, seropositivity rates in HPV-6/11/16/18 vaccine group decreased considerably, particularly in the older age groups. In the total vaccinated cohort (regardless of baseline serological and HPV-DNA status), anti-HPV-16 and -18 neutralizing antibody levels induced by HPV-16/18 vaccine were higher than those induced by HPV-6/11/16/18 vaccine. CD4+ T-cell response for HPV-16 and HPV-18 was higher in HPV-16/18 vaccine group than in HPV-6/11/16/18 vaccine group. Memory B-cell responses appeared similar between vaccine groups. Both vaccines were generally well tolerated. Overall, the higher immune response observed with the HPV-16/18 vaccine was maintained up to Month 48. A head-to-head study incorporating clinical endpoints would be required to confirm whether the observed differences in immune response between the vaccines influence the duration of protection they provided.
Original language | English (US) |
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Pages (from-to) | 3455-3465 |
Number of pages | 11 |
Journal | Human Vaccines and Immunotherapeutics |
Volume | 10 |
Issue number | 12 |
DOIs | |
State | Published - Dec 1 2014 |
Keywords
- Cervarix®
- Gardasil®
- Human papillomavirus
- Immunogenicity
- Safety
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology
- Pharmacology