- Revaccination with 9-valent HPV (9vHPV) vaccine may offer cross-protection against additional HPV types.
- Significant declines in 4-valent HPV (4vHPV) types in unvaccinated women suggest that high vaccination uptake may confer herd protection.
Why this matters
- Consider revaccination with 9vHPV in young females who completed >1 dose 4vHPV vaccine.
- 1580 participants.
- HPV vaccination rates (>1 dose) increased from 0%, 59.2%, 71.5%, and 83.4% in waves 1-4, respectively.
- Proportion of vaccinated women infected with >1 9vHPV, >1 4vHPV vaccine-type, >5 types in 9- but not 4-vaccine-type HPV declined 71%, 80.9%, 68.8%, respectively.
- Proportion of unvaccinated women infected with >1 4vHPV vaccine-type declined 40.1% (adjusted OR [aOR], 0.50; 95% CI, 0.26-0.97).
- Vaccine effectiveness (VE) in waves 3, 4 was 90.6%, 80.1%, respectively.
- Vaccinated: odds of infection decreased for 9vHPV vaccine (aOR, 0.18; 95% CI, 0.12-0.28), 5 additional HPV types for 9-valent (aOR, 0.26; 95% CI, 0.16-0.42).
- Related editorial.
- Surveillance study evaluating 4 cross-sectional cohorts of adolescents, young women (ages 13-26 years) to determine trends in vaccine-type HPV in vaccinated (to assess VE) and unvaccinated (to assess herd protection) from 2006 to 2017.
- Funding: NIH.
- Limited ability to evaluate 9vHPV prevalence trends in wave 4.
- Limited generalizability.
- Self-report bias.