Efficacy, safety, and immunogenicity of an Escherichia coli-produced nine-valent human papillomavirus vaccine: a multicentre, double-blind, randomised, controlled, phase 3 trial.
Hong-Xing Pan, Zhao-Feng Bi, Yu-Lin Jing et al.
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In 30 seconds
This multicentre, double-blind, randomised phase 3 trial compared an Escherichia coli-produced nine-valent HPV vaccine with a bivalent vaccine in healthy, unvaccinated women aged 18–45 years in China. Among 9,327 participants, antibody responses to HPV 16 and 18 met the prespecified non-inferiority criteria. In the modified intention-to-treat population, efficacy against 12-month persistent infection with HPV types 31, 33, 45, 52, and 58 was 98.2% (95% CI 89.6–100). Adverse reactions were more frequent with the nine-valent vaccine, while serious adverse events occurred at similar rates and none were considered vaccine-related.
Key findings
- Antibody responses to HPV 16 and 18 were non-inferior to those elicited by the bivalent vaccine.
- Efficacy against 12-month persistent infection with HPV types 31, 33, 45, 52, and 58 was 98.2% (95% CI 89.6–100).
- Adverse reactions occurred in 52.1% of the nine-valent group and 42.2% of the bivalent group.
- Serious adverse events occurred in 11.0% and 10.3%, respectively; none were considered related to vaccination.
Why it matters
The trial provides comparative phase 3 evidence that this nine-valent vaccine generates non-inferior responses to HPV 16 and 18 while protecting against persistent infection from five additional vaccine-targeted types. Its safety findings help characterise the trade-off of more reported adverse reactions without an apparent increase in serious events. The authors note that low production cost could support broader access, although access was not tested in this trial.
What to keep in mind
Follow-up was ongoing, so the abstract reports persistent-infection efficacy and immunogenicity outcomes rather than longer-term protection.