HPV vaccines (2v, 4v, 9v)

After 5-8 years of vaccination, the prevalence of HPV 16 and 18 decreased significantly by 83% (RR 0·17, 95% CI 0·11-0·25) among girls aged 13-19 years, and decreased significantly by 66% (RR 0·34, 95% CI 0·23-0·49) among women aged 20-24 years.

The prevalence of HPV 31, 33, and 45 decreased significantly by 54% (RR 0·46, 95% CI 0·33-0·66) among girls aged 13-19 years.

Within a decade following the U.S. introduction of quadrivalent HPV vaccine in 2006, prevalence of HPV types 6, 11, 16, and 18 decreased 86% among females age 14 through 19 years and decreased 71% among females age 20 through 24 years.

VE against 12-month persistent infection with HPV-16/18 was 89.9% (84.0, 94.0), and that against HPV-31/33/45/51 was 49.0% (34.7, 60.3).

VE against 12-month persistent infection with HPV-16/18 was 89.9% (84.0, 94.0), and that against HPV-31/33/45/51 was 49.0% (34.7, 60.3).

Vaccine efficacy against incident HPV-16/18 infections for three doses was 77·0% (95% CI 74·7-79·1), two doses was 76·0% (62·0-85·3), and one dose was 85·7% (70·7-93·7).

Vaccine efficacy against incident HPV-16/18 infections for three doses was 77·0% (95% CI 74·7-79·1), two doses was 76·0% (62·0-85·3), and one dose was 85·7% (70·7-93·7).

Vaccine efficacy against incident HPV-16/18 infections for three doses was 77·0% (95% CI 74·7-79·1), two doses was 76·0% (62·0-85·3), and one dose was 85·7% (70·7-93·7).

Vaccine efficacy against incident HPV-31/33/45 infections for three doses was 59·7% (56·0-63·0), two doses was 37·7% (12·4-55·9), and one dose was 36·6% (-5·4 to 62·2).

RESULTS: Vaccine efficacy against the combined incidence of persistent infection, CIN/EGL related to HPV6/11/16/18 in the per-protocol population was 88.7% (95% CI: 78.1, 94.8).

Efficacy for women who were seropositive and DNA negative for the relevant vaccine HPV type at the time of enrolment who received at least 1 dose was 66.9% (95% CI: 4.3, 90.6).

At month 84, in women seronegative for the corresponding HPV type in the according-to-protocol cohort for efficacy, vaccine efficacy against 6-month persistent infection or CIN1+ associated with HPV 16/18 was significant in all age groups combined (90·5%, 96·2% CI 78·6-96·5).

We also noted significant cross-protective efficacy against 6-month persistent infection with HPV 31 (65·8%, 96·2% CI 24·9-85·8) and HPV 45 (70·7%, 96·2% CI 34·2-88·4).

Nonavalent VE was 98.8% (95% CI 91.3-99.8%, P < 0.0001) and bivalent VE was 97.5% (95% CI 90.0-99.4%, P < 0.0001).

Nonavalent VE was 98.8% (95% CI 91.3-99.8%, P < 0.0001) and bivalent VE was 97.5% (95% CI 90.0-99.4%, P < 0.0001).

Overall, 89 persistent infections were detected in the HPV 16/18/31/33/45/52/58 mITT cohort: 5 in the nonavalent group and 84 in the control group; nonavalent VE was 95.5% (95% CI 89.0-98.2%, P < 0.0001).

The rate difference between one and two doses of the bivalent vaccine was -0.13 infections per 100 participants (95% confidence interval [CI], -0.45 to 0.15; P<0.001 for noninferiority), and the difference between one and two doses of the nonavalent vaccine was 0.21 infections per 100 participants (95% CI, -0.09 to 0.51; P<0.001 for noninferiority).

The rate difference between one and two doses of the bivalent vaccine was -0.13 infections per 100 participants (95% confidence interval [CI], -0.45 to 0.15; P<0.001 for noninferiority), and the difference between one and two doses of the nonavalent vaccine was 0.21 infections per 100 participants (95% CI, -0.09 to 0.51; P<0.001 for noninferiority).

Over a median 10.2-year follow-up, vaccine efficacy was 87.5% (95% CI 6.4-99.7) against high-grade cervical, vulvar or vaginal lesions (1 case in the vaccine group and 8 cases in the control group, P = 0.0391), and 97.0% (95% CI 78.9-100.0) against persistent infection (over 6 months, 1 case in the vaccine group and 32 cases in the control group, P < 0.0001) in the per-protocol population.

RESULTS: Among women in the three-dose, two-dose 0/6 , two-dose 0/1 , and one-dose groups, cumulative incident HPV16/18 infection rates (No. of events/No. of individuals) were 4.3% (88/2036, 95% confidence interval [CI] = 3.5% to 5.3%), 3.8% (3/78, 95% CI = 1.0% to 10.1%), 3.6% (7/192, 95% CI = 1.6% to 7.1%), and 1.5% (2/133, 95% CI = 0.3% to 4.9%; P = 1.00, .85, .17 comparing the two-dose 0/6 , two-dose 0/1 , and one-dose groups to the three-dose group, respectively).

RESULTS: Among women in the three-dose, two-dose 0/6 , two-dose 0/1 , and one-dose groups, cumulative incident HPV16/18 infection rates (No. of events/No. of individuals) were 4.3% (88/2036, 95% confidence interval [CI] = 3.5% to 5.3%), 3.8% (3/78, 95% CI = 1.0% to 10.1%), 3.6% (7/192, 95% CI = 1.6% to 7.1%), and 1.5% (2/133, 95% CI = 0.3% to 4.9%; P = 1.00, .85, .17 comparing the two-dose 0/6 , two-dose 0/1 , and one-dose groups to the three-dose group, respectively).

Vaccine efficacy against persistent HPV 16 and 18 infection among participants evaluable for the endpoint was 95·4% (95% CI 85·0-99·9) in the single-dose default cohort (2135 women assessed), 93·1% (77·3-99·8) in the two-dose cohort (1452 women assessed), and 93·3% (77·5-99·7) in three-dose recipients (1460 women assessed).

Vaccine efficacy against persistent HPV 16 and 18 infection among participants evaluable for the endpoint was 95·4% (95% CI 85·0-99·9) in the single-dose default cohort (2135 women assessed), 93·1% (77·3-99·8) in the two-dose cohort (1452 women assessed), and 93·3% (77·5-99·7) in three-dose recipients (1460 women assessed).

Vaccine efficacy against persistent HPV 16 and 18 infection among participants evaluable for the endpoint was 95·4% (95% CI 85·0-99·9) in the single-dose default cohort (2135 women assessed), 93·1% (77·3-99·8) in the two-dose cohort (1452 women assessed), and 93·3% (77·5-99·7) in three-dose recipients (1460 women assessed).

The prevalence of oral HPV16/18/6/11 infections was significantly reduced in vaccinated versus unvaccinated individuals (0.11% v 1.61%; Padj = .008), corresponding to an estimated 88.2% (95% CI, 5.7% to 98.5%) reduction in prevalence after model adjustment for age, sex, and race.

There is high-certainty evidence that vaccines lower CIN2+ from 164 to 2/10,000 (RR 0.01 (0 to 0.05)) and CIN3+ from 70 to 0/10,000 (RR 0.01 (0.00 to 0.10).

There is high-certainty evidence that vaccines lower CIN2+ from 164 to 2/10,000 (RR 0.01 (0 to 0.05)) and CIN3+ from 70 to 0/10,000 (RR 0.01 (0.00 to 0.10).

There is moderate-certainty evidence that vaccines reduce the risk of AIS from 9 to 0/10,000 (RR 0.10 (0.01 to 0.82).HPV vaccines reduce the risk of any CIN2+ from 287 to 106/10,000 (RR 0.37 (0.25 to 0.55), high certainty) and probably reduce any AIS lesions from 10 to 0/10,000 (RR 0.1 (0.01 to 0.76), moderate certainty).

The size of reduction in CIN3+ with vaccines differed between bivalent and quadrivalent vaccines (bivalent: RR 0.08 (0.03 to 0.23), high certainty; quadrivalent: RR 0.54 (0.36 to 0.82), moderate certainty).

The size of reduction in CIN3+ with vaccines differed between bivalent and quadrivalent vaccines (bivalent: RR 0.08 (0.03 to 0.23), high certainty; quadrivalent: RR 0.54 (0.36 to 0.82), moderate certainty).

Data in older women were not available for this comparison.HPV16/18 negativeIn those aged 15 to 26 years, vaccines reduce CIN2+ associated with HPV16/18 from 113 to 6 /10,000 (RR 0.05 (0.03 to 0.10).

In women 24 years or older the absolute and relative reduction in the risk of these lesions is smaller (from 45 to 14/10,000, (RR 0.30 (0.11 to 0.81), moderate certainty).

No data are reported for more severe lesions.Regardless of HPV DNA statusIn younger women HPV vaccines reduce the risk of CIN2+ associated with HPV16/18 from 341 to 157/10,000 (RR 0.46 (0.37 to 0.57), high certainty).

The number of women with AIS associated with HPV16/18 is reduced from 14 to 5/10,000 with HPV vaccines (high certainty).HPV vaccines reduce any CIN2+ from 559 to 391/10,000 (RR 0.70 (0.58 to 0.85, high certainty) and any AIS from 17 to 5/10,000 (RR 0.32 (0.15 to 0.67), high certainty).

The reduction in any CIN3+ differed by vaccine type (bivalent vaccine: RR 0.55 (0.43 to 0.71) and quadrivalent vaccine: RR 0.81 (0.69 to 0.96)).In women vaccinated at 24 to 45 years of age, there is moderate-certainty evidence that the risks of CIN2+ associated with HPV16/18 and any CIN2+ are similar between vaccinated and unvaccinated women (RR 0.74 (0.52 to 1.05) and RR 1.04 (0.83 to 1.30) respectively).

The reduction in any CIN3+ differed by vaccine type (bivalent vaccine: RR 0.55 (0.43 to 0.71) and quadrivalent vaccine: RR 0.81 (0.69 to 0.96)).In women vaccinated at 24 to 45 years of age, there is moderate-certainty evidence that the risks of CIN2+ associated with HPV16/18 and any CIN2+ are similar between vaccinated and unvaccinated women (RR 0.74 (0.52 to 1.05) and RR 1.04 (0.83 to 1.30) respectively).

The reduction in any CIN3+ differed by vaccine type (bivalent vaccine: RR 0.55 (0.43 to 0.71) and quadrivalent vaccine: RR 0.81 (0.69 to 0.96)).In women vaccinated at 24 to 45 years of age, there is moderate-certainty evidence that the risks of CIN2+ associated with HPV16/18 and any CIN2+ are similar between vaccinated and unvaccinated women (RR 0.74 (0.52 to 1.05) and RR 1.04 (0.83 to 1.30) respectively).

The reduction in any CIN3+ differed by vaccine type (bivalent vaccine: RR 0.55 (0.43 to 0.71) and quadrivalent vaccine: RR 0.81 (0.69 to 0.96)).In women vaccinated at 24 to 45 years of age, there is moderate-certainty evidence that the risks of CIN2+ associated with HPV16/18 and any CIN2+ are similar between vaccinated and unvaccinated women (RR 0.74 (0.52 to 1.05) and RR 1.04 (0.83 to 1.30) respectively).

In 15- to 25-year-old females, there was a reduction in CIN2+ irrespective of HPV type after six years (RR 0.70, 95% CI 0.56 to 0.88) (moderate-certainty) and a larger reduction in CIN2+ from vaccine-matched HPV types after six years (RR 0.40, 95% CI 0.30 to 0.54) (moderate-certainty).

In 15- to 25-year-old females, there was a reduction in CIN2+ irrespective of HPV type after six years (RR 0.70, 95% CI 0.56 to 0.88) (moderate-certainty) and a larger reduction in CIN2+ from vaccine-matched HPV types after six years (RR 0.40, 95% CI 0.30 to 0.54) (moderate-certainty).

Treatment rates for HPV-related pre-invasive disease In pairwise analysis of five studies with 38,606 participants, there were 12 fewer people that needed to seek treatment per 1000 participants (95% CI 5 to 17 fewer per 1000) in the HPV vaccine groups compared with the control group rate at up to 84 months follow-up (RR 0.76, 95% CI 0.65 to 0.89) (moderate-certainty).

After 5-9 years of vaccination, CIN2+ decreased significantly by 51% (RR 0·49, 95% CI 0·42-0·58) among screened girls aged 15-19 years and decreased significantly by 31% (RR 0·69, 95% CI 0·57-0·84) among women aged 20-24 years.

Vaccine efficacy for the prevention of the primary composite end point was 98% (95.89% confidence interval [CI], 86 to 100) in the per-protocol susceptible population and 44% (95% CI, 26 to 58) in an intention-to-treat population of all women who had undergone randomization (those with or without previous infection).

Vaccine efficacy for the prevention of the primary composite end point was 98% (95.89% confidence interval [CI], 86 to 100) in the per-protocol susceptible population and 44% (95% CI, 26 to 58) in an intention-to-treat population of all women who had undergone randomization (those with or without previous infection).

The estimated vaccine efficacy against all high-grade cervical lesions, regardless of causal HPV type, in this intention-to-treat population was 17% (95% CI, 1 to 31).

FINDINGS: Vaccine efficacy against CIN3+ associated with HPV-16/18 was 100% (95% CI 85·5-100) in the TVC-naive and 45·7% (22·9-62·2) in the TVC.

FINDINGS: Vaccine efficacy against CIN3+ associated with HPV-16/18 was 100% (95% CI 85·5-100) in the TVC-naive and 45·7% (22·9-62·2) in the TVC.

Vaccine efficacy against all CIN3+ (irrespective of HPV type in the lesion and including lesions with no HPV DNA detected) was 93·2% (78·9-98·7) in the TVC-naive and 45·6% (28·8-58·7) in the TVC.

Vaccine efficacy against all CIN3+ (irrespective of HPV type in the lesion and including lesions with no HPV DNA detected) was 93·2% (78·9-98·7) in the TVC-naive and 45·6% (28·8-58·7) in the TVC.

VE against CIN1+, CIN2+, and CIN3+ irrespective of HPV DNA was 21.7% (10.7, 31.4), 30.4% (16.4, 42.1), and 33.4% (9.1, 51.5) and was consistently significant only in 15- to 17-year-old women (27.4% [10.8, 40.9], 41.8% [22.3, 56.7], and 55.8% [19.2, 76.9]).

Vaccine efficacy against CIN2+ associated with the composite of 12 non-vaccine HPV types (31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68), with or without HPV-16/18 co-infection, was 46·8% (95% CI 30·7-59·4) in the ATP-E, 56·2% (37·2-69·9) in the TVC-naive, and 34·2% (20·4-45·8) in the TVC.

Corresponding values for CIN3+ were 73·8% (48·3-87·9), 91·4% (65·0-99·0), and 47·5% (22·8-64·8).

Vaccine efficacy against CIN2+ associated with the composite of 12 non-vaccine HPV types (31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68), with or without HPV-16/18 co-infection, was 46·8% (95% CI 30·7-59·4) in the ATP-E, 56·2% (37·2-69·9) in the TVC-naive, and 34·2% (20·4-45·8) in the TVC.

The rate of high-grade cervical, vulvar, or vaginal disease related to HPV-31, 33, 45, 52, and 58 in a prespecified per-protocol efficacy population (susceptible population) was 0.1 per 1000 person-years in the 9vHPV group and 1.6 per 1000 person-years in the qHPV group (efficacy of the 9vHPV vaccine, 96.7%; 95% confidence interval, 80.9 to 99.8).

In the total vaccinated cohort, vaccine efficacy against CIN1+ irrespective of HPV was significant (22·9%, 96·2% CI 4·8-37·7).

Over a median 10.2-year follow-up, vaccine efficacy was 87.5% (95% CI 6.4-99.7) against high-grade cervical, vulvar or vaginal lesions (1 case in the vaccine group and 8 cases in the control group, P = 0.0391), and 97.0% (95% CI 78.9-100.0) against persistent infection (over 6 months, 1 case in the vaccine group and 32 cases in the control group, P < 0.0001) in the per-protocol population.

Effectiveness against CIN2+ was 64% (IRR = 0.36, 95%CI = 0.27–0.47) for those initiating vaccination before age 17, and 25% (IRR = 0.75, 95%CI = 0.66–0.86) and 14% (IRR = 0.86, 95%CI = 0.73–1.01) for those initiating vaccination at ages 17–19, and at ages 20–29, respectively.

Effectiveness against CIN2+ was 64% (IRR = 0.36, 95%CI = 0.27–0.47) for those initiating vaccination before age 17, and 25% (IRR = 0.75, 95%CI = 0.66–0.86) and 14% (IRR = 0.86, 95%CI = 0.73–1.01) for those initiating vaccination at ages 17–19, and at ages 20–29, respectively.

Effectiveness against CIN2+ was 64% (IRR = 0.36, 95%CI = 0.27–0.47) for those initiating vaccination before age 17, and 25% (IRR = 0.75, 95%CI = 0.66–0.86) and 14% (IRR = 0.86, 95%CI = 0.73–1.01) for those initiating vaccination at ages 17–19, and at ages 20–29, respectively.

Vaccine effectiveness of 100% (95% CI 94·7-100) was demonstrated for ≥12 years, with a trend toward continued protection through 14 years post-vaccination.

The corresponding risk reductions for CIN3 were 39% (95% CI 36-41) for those offered at age 16-18 years, 75% (72-77) for age 14-16 years, and 97% (96-98) for age 12-13 years.

Compared with unvaccinated women born in 1988, vaccinated women born in 1995 and 1996 showed an 89% reduction (95% confidence interval 81% to 94%) in prevalent cervical intraepithelial neoplasia (CIN) grade 3 or worse (from 0.59% (0.48% to 0.71%) to 0.06% (0.04% to 0.11%)), an 88% reduction (83% to 92%) in CIN grade 2 or worse (from 1.44% (1.28% to 1.63%) to 0.17% (0.12% to 0.24%)), and a 79% reduction (69% to 86%) in CIN grade 1 (from 0.69% (0.58% to 0.63%) to 0.15% (0.10% to 0.21%)).

Younger age at immunisation was associated with increasing vaccine effectiveness: 86% (75% to 92%) for CIN grade 3 or worse for women vaccinated at age 12-13 compared with 51% (28% to 66%) for women vaccinated at age 17.

We found considerable vaccine effectiveness against CIN3+ after 1 (IRR, 0.38 [95% CI, .14-.98]), 2 (IRR, 0.38 [95% CI, .22-.66]), or 3 (IRR, 0.37 [95% CI, .30-.45]) vaccine doses, compared to unvaccinated women.

We found considerable vaccine effectiveness against CIN3+ after 1 (IRR, 0.38 [95% CI, .14-.98]), 2 (IRR, 0.38 [95% CI, .22-.66]), or 3 (IRR, 0.37 [95% CI, .30-.45]) vaccine doses, compared to unvaccinated women.

After additional adjustment for other covariates, the incidence rate ratio was 0.37 (95% CI, 0.21 to 0.57).

After adjustment for all covariates, the incidence rate ratio was 0.12 (95% CI, 0.00 to 0.34) among women who had been vaccinated before the age of 17 years and 0.47 (95% CI, 0.27 to 0.75) among women who had been vaccinated at the age of 17 to 30 years.

After adjustment for all covariates, the incidence rate ratio was 0.12 (95% CI, 0.00 to 0.34) among women who had been vaccinated before the age of 17 years and 0.47 (95% CI, 0.27 to 0.75) among women who had been vaccinated at the age of 17 to 30 years.

Among participants vaccinated before 17 years, the overall fully adjusted incidence rate ratios compared with the unvaccinated group was 0.21 (95% confidence interval (CI) 0.13 to 0.32), with sustained protection for 13-15 years after vaccination (incidence rate ratio 0.23, 95% CI 0.11 to 0.46).

Among participants vaccinated before 17 years, the overall fully adjusted incidence rate ratios compared with the unvaccinated group was 0.21 (95% confidence interval (CI) 0.13 to 0.32), with sustained protection for 13-15 years after vaccination (incidence rate ratio 0.23, 95% CI 0.11 to 0.46).

For individuals vaccinated at 17 years or older, the overall fully adjusted incidence rate ratio was 0.63 (95% CI 0.49 to 0.81) compared with the unvaccinated group, with significant incidence reductions observed during years 10-12 (incidence rate ratio 0.54, 95% CI 0.33 to 0.86), and years 13-15 (incidence rate ratio 0.23, 95% CI 0.08 to 0.60) after vaccination.

The estimated relative reduction in cervical cancer rates by age at vaccine offer were 34% (95% CI 25-41) for age 16-18 years (school year 12-13), 62% (52-71) for age 14-16 years (school year 10-11), and 87% (72-94) for age 12-13 years (school year 8), compared with the reference unvaccinated cohort.

The estimated relative reduction in cervical cancer rates by age at vaccine offer were 34% (95% CI 25-41) for age 16-18 years (school year 12-13), 62% (52-71) for age 14-16 years (school year 10-11), and 87% (72-94) for age 12-13 years (school year 8), compared with the reference unvaccinated cohort.

The estimated relative reduction in cervical cancer rates by age at vaccine offer were 34% (95% CI 25-41) for age 16-18 years (school year 12-13), 62% (52-71) for age 14-16 years (school year 10-11), and 87% (72-94) for age 12-13 years (school year 8), compared with the reference unvaccinated cohort.

In the birth cohort of women offered vaccination routinely at age 12-13 years, adjusted age standardised incidence rates of cervical cancer and CIN3 in the additional 12 months of follow-up (1 July 2019 to 30 June 2020) were, respectively, 83.9% (95% confidence interval (CI) 63.8% to 92.8%) and 94.3% (92.6% to 95.7%) lower than in the reference cohort of women who were never offered HPV vaccination.

Women vaccinated at 14 to 22 years of age and given 3 doses of the bivalent vaccine showed a significant reduction in incidence compared with all unvaccinated women (3.2/100 000 [95% confidence interval (CI) = 2.1 to 4.6] vs 8.4 [95% CI = 7.2 to 9.6]).

There was a reduction in high-grade anal intraepithelial neoplasia (AIN) irrespective of HPV type in the Gardasil group in one study in men who have sex with men (RR 0.75, 95% CI 0.53 to 1.07) (low-certainty).

For both high-grade penile intraepithelial neoplasia (PeIN) irrespective of HPV type and vaccine-matched HPV-type high-grade PeIN, little to no difference per 1000 participants was reported in the Gardasil group in one study with 3880 participants at 36 months follow-up (RR 1.00, 95% CI 0.20 to 4.93) (low-certainty).

Anogenital warts In pairwise analysis of three studies with 21,271 participants, there were 25 fewer cases of anogenital warts irrespective of HPV type per 1000 participants (95% CI 22 to 28 fewer per 1000) in the HPV vaccine groups compared with the control group rate at up to 48 months follow-up (RR 0.38, 95% CI 0.32 to 0.46) (high-certainty).

Among boys aged 15-19 years anogenital wart diagnoses decreased significantly by 48% (RR 0·52, 95% CI 0·37-0·75) and among men aged 20-24 years they decreased significantly by 32% (RR 0·68, 95% CI 0·47-0·98).

In the per-protocol population, efficacy against lesions related to HPV-6, 11, 16, or 18 was 90.4% (95% CI, 69.2 to 98.1).

RESULTS: In the intention-to-treat population, 36 external genital lesions were seen in the vaccine group as compared with 89 in the placebo group, for an observed efficacy of 60.2% (95% confidence interval [CI], 40.8 to 73.8); the efficacy was 65.5% (95% CI, 45.8 to 78.6) for lesions related to HPV-6, 11, 16, or 18.

RESULTS: Efficacy of the qHPV vaccine against anal intraepithelial neoplasia associated with HPV-6, 11, 16, or 18 was 50.3% (95% confidence interval [CI], 25.7 to 67.2) in the intention-to-treat population and 77.5% (95% CI, 39.6 to 93.3) in the per-protocol efficacy population; the corresponding efficacies against anal intraepithelial neoplasia associated with HPV of any type were 25.7% (95% CI, -1.1 to 45.6) and 54.9% (95% CI, 8.4 to 79.1), respectively.

RESULTS: Efficacy of the qHPV vaccine against anal intraepithelial neoplasia associated with HPV-6, 11, 16, or 18 was 50.3% (95% confidence interval [CI], 25.7 to 67.2) in the intention-to-treat population and 77.5% (95% CI, 39.6 to 93.3) in the per-protocol efficacy population; the corresponding efficacies against anal intraepithelial neoplasia associated with HPV of any type were 25.7% (95% CI, -1.1 to 45.6) and 54.9% (95% CI, 8.4 to 79.1), respectively.

The rate of grade 2 or 3 anal intraepithelial neoplasia related to infection with HPV-6, 11, 16, or 18 was reduced by 54.2% (95% CI, 18.0 to 75.3) in the intention-to-treat population and by 74.9% (95% CI, 8.8 to 95.4) in the per-protocol efficacy population.

In early vaccine group participants during long-term follow-up compared with the placebo group in the base study, the incidence per 10 000 person-years of external genital warts related to HPV6 or 11 was 0·0 (95% CI 0·0-8·7) versus 137·3 (83·9-212·1), of external genital lesions related to HPV6, 11, 16, or 18 was 0·0 (0·0-7·7) versus 140·4 (89·0-210·7), and of anal intraepithelial neoplasia or anal cancer related to HPV6, 11, 16, or 18 in MSM only was 20·5 (0·5-114·4) versus 906·2 (553·5-1399·5).

For girls initiating vaccination at age 12-14 years and 15-16 years, 1-dose vaccine effectiveness (VE) was 71% (IRR = 0.29; 95% CI, .22-.38) and 62% (0.38; .29-.49), respectively, compared with unvaccinated girls.

RESULTS: The VE against the first episode of AGW was strongly dependent on vaccination age, with hazard ratios (HRs) compared to unvaccinated individuals of 0.2, 0.2, 0.3, 0.5, 1.0, 1.3, and 2.7, for age groups of ⩽13, 14-15, 16-17, 18-19, 20-24, 25-29, and 30+ years at first vaccination, respectively.

After vaccination began, a decline in number of diagnoses of genital warts was noted for young female residents (59%, p(trend)<0·0001).

Rates declined from 0.16 per 100000 in 2012 to 0.02 per 100000 in 2016 (P = .034).