The HPV vaccines first became available in 2006 and many countries rapidly introduced school-based vaccination programs targeted at specific age cohorts of young women. In countries with high coverage rates such as Australia, dramatic reductions in vaccine-targeted HPV infections and cytologic abnormalities have now been documented in the vaccinated age groups. In contrast, in the U.S. vaccination has been opportunistic, many vaccine recipients have been older and coverage rates have been lower. This suggests that the impact of vaccination may be less in the U.S. than in other countries. Few studies have assessed vaccine impact on the prevalence of HPV genotypes and cytological abnormalities in women in the U.S.
The BD HPV Onclarity study is an ongoing U.S. study involving 31 collection sites in 18 states. 33,858 women 21-83 years were enrolled between August 2013–June 2015. At enrollment, women had a gynecologic examination including a SurePath cytology specimen that was tested for high-risk HPV genotypes using the BD HPV Onclarity assay that provides genotyping information for HPV 16, 18, 31, 33/58, 35/39/68, 45, 51, 52, 56/59/66. We compared the prevalence of HPV genotypes and cytological abnormalities in women 21-34 years stratified by self-reported HPV vaccination history. A Mantel-Haenszel (MH) analysis was performed to determine association between vaccination status and prevalence, adjusting for age.
The Table shows significant differences between unvaccinated (UV) and vaccinated (V) women in the prevalence of HPV 16, HPV 18, and HPV 31.
| 21- | 24 | 25- | 29 | 30- | 34 | ||
| UV | V | UV | V | UV | V |
MH p-value |
|
| Number | 2380 | 1424 | 4118 | 1187 | 4678 | 366 | |
| HPV+ | 31.1% | 27.0% | 22.1% | 19.4% | 15.3% | 11.5% | <0.001 |
| HPV 16+ | 5.1% | 1.1% | 3.9% | 1.6% | 2.4% | 1.1% | <0.001 |
| HPV 18+ | 1.8% | 0.2% | 1.4% | 0.3% | 1.1% | 0.3% | <0.001 |
| HPV 31+ | 2.6% | 1.5% | 2.4% | 1.0% | 2.1% | 1.9% | <0.001 |
|
ASCUS/HPV+ or LSIL+ |
12.9% | 10.5% | 9.1% | 7.2% | 6.1% | 4.1% | 0.001 |
| HSIL+ | 0.7% | 0.1% | 1.0% | 0.8% | 1.0% | 0.5% | 0.049 |
Minor differences were observed in the prevalence of other HPV genotypes. Moreover the prevalence of cytologic abnormalities is lower. Although the impact of vaccination is greatest in women 21-24 years significant reductions in the prevalence of specific HPV infections and cytologic abnormalities were observed in women 30-34 years of age. This age cohort could have been no younger than 21-25 years at the time of their vaccination, based on study enrollment date.
A prior history of HPV vaccination is associated with significant reductions in the prevalence of HPV 16, 18, 31 and ASCUS-HPV(+)/LSIL+ and HSIL+ in women 21-34 years of age. The data indicates that vaccination of women in the older range of the recommended U.S. catch-up age group provides considerable benefit.