Table 3. Projected reductions in anogenital HPV16 infection prevalence among MSM from prophylactic vaccination.
| Strategy | Uptake± | Efficacy¶ | Vaccine coverage among MSM | Penile HPV16 prevalence reduction* | Anal HPV16 prevalence reduction* | |||
|---|---|---|---|---|---|---|---|---|
| Ultimate | After 25 years | Ultimate† | After 25 years†† | Ultimate† | After 25 years†† | |||
| MSM ≤26 years | Base-case | 85% all-or-nothing | 9.4% | 7.5% | 14.3% (9.4%–18.8%) | 10.7% (5.6%–14.5%) | 13.4% (7.5%–17.8%) | 9.9% (4.5%–13.7%) |
| Improved | 85% all-or-nothing | 17.6% | 14.0% | 26.2% (17.4%–34.4%) | 19.6% (10.4%–26.5%) | 24.6% (14.1%–32.3%) | 18.2% (8.5%–25.1%) | |
| Base-case | 85% leaky if susceptible§ | 9.4% | 7.5% | 5.9% (2.5%–9.9%) | 4.3% (1.7%–6.7%) | 6.1% (2.6%–9.5%) | 4.4% (2.0%–7.0%) | |
| MSM ≤40 years | Base-case | 85% all-or-nothing | 19.2% | 16.6% | 27.2% (15.3%–37.2%) | 22.6% (10.2%–31.5%) | 25.5% (11.6%–34.8%) | 20.9% (7.6%–29.7%) |
| Improved | 85% all-or-nothing | 33.8% | 29.6% | 46.2% (27.4%–63.0%) | 38.8% (18.2%–53.1%) | 43.6% (21.4%–58.7%) | 36.2% (13.8%–50.7%) | |
| Base-case | 85% leaky if susceptible§ | 19.2% | 16.6% | 10.4% (3.9%–16.9%) | 8.2% (3.0%–13.5%) | 11.0% (4.8%–17.4%) | 8.7% (4.0%–14.0%) | |
| All MSM | Base-case | 85% all-or-nothing | 21.2% | 18.8% | 29.2% (15.9%–40.2%) | 24.8% (10.7%–34.7%) | 27.3% (11.9%–37.5%) | 23.0% (7.9%–32.8%) |
| Improved | 85% all-or-nothing | 36.5% | 33.1% | 48.8% (28.1%–66.9%) | 42.2% (19.0%–57.8%) | 46.1% (21.8%–62.4%) | 39.4% (14.3%–55.4%) | |
| Base-case | 85% leaky if susceptible§ | 21.2% | 18.8% | 11.1% (4.2%–18.1%) | 8.9% (3.2%–15.0%) | 11.7% (5.1%–18.6%) | 9.5% (4.3%–15.4%) | |
| Preadolescent boys | 40% at 12 y | 95% all-or-nothing | 39.7% | 19.6% | 64.1% (53.2%–79.7%) | 20.0% (9.6%–25.9%) | 61.6% (48.4%–75.7%) | 19.0% (10.8%–24.4%) |
| 80% at 12 y | 95% all-or-nothing | 79.3% | 39.5% | 97.9% (92.3%–99.9%) | 37.7% (18.0%–48.0%) | 97.4% (89.5%–99.9%) | 36.0% (20.9%–45.4%) | |
| 40% at 12 y | 95% leaky | 39.7% | 19.6% | 60.9% (45.4%–78.9%) | 18.8% (9.4%–25.0%) | 57.9% (38.2%–74.7%) | 17.4% (10.0%–23.5%) | |
| Preadolescent boys + all MSM | 40% at 12 y + base-case | 95% (at 12 y) + 85% all-or-nothing | 52.3% | 32.8% | 77.1% (64.9%–95.2%) | 46.5% (23.7%–59.6%) | 74.8% (59.8%–93.0%) | 44.2% (23.6%–57.2%) |
±“Base-case” assumes similar age-specific uptake for selective MSM vaccination as realized for HepB vaccine; “improved” assumes doubled uptake as compared to HepB vaccine among MSM.
¶”All-or-nothing” assumes x% become fully protected and (100 − x)% remain fully susceptible; “leaky” assumes uniform x% infection hazard reductions.
*Percentage reduction in prevalence of infection at time t with vaccination, compared to prevalence of infection prior to introduction of vaccination.
†Model-averaged maximum (90% prediction interval) achieved in the post-vaccine epidemiologic equilibrium.
††Model-average (90% prediction interval) achieved after 25 years of vaccination strategy implementation.
§Susceptible for both penile and anal HPV16 infection.
HepB, hepatitis B; HPV16, human papillomavirus genotype 16; MSM, men who have sex with men.