Immune response to the HPV-16/18 AS04-adjuvanted vaccine administered as a 2-dose or 3-dose schedule up to 4 years after vaccination: results from a randomized study

Preconception care interventions among adolescents and young adults to prevent adverse maternal, perinatal and child health outcomes: An evidence gap map

OBJECTIVE

To identify gaps in existing evidence on preconception health interventions to improve the health outcomes of adolescents, young adults, and their offspring.

STUDY DESIGN

Evidence gap map (EGM) METHODS: Following the Campbell guidelines, we included reviews and interventional studies identified through searches on Medline and other electronic databases from 2010 to July 18th, 2023. Dual screening of titles/abstracts and full texts was conducted on Covidence software, followed by quality assessment and development of 2D-EGM using the EPPI-Reviewer and Mapper software.

RESULTS

A total of 18 studies (124 papers) were identified, of which most of the studies were from higher- and upper-middle-income countries, with limited evidence from low-middle-income countries. More than half focused on females with limited evidence on men. The monitoring of adverse events of human papillomavirus (HPV) vaccination was the most well-evidenced area, with very little evidence on the herpes simplex virus candidate vaccine and other behavioural interventions. Perinatal outcomes were the most frequently reported outcomes followed by maternal and child health outcomes. Healthcare facilities (mostly clinical trials) were the most utilised delivery platforms, with limited or no evidence on communities, schools, and digital platforms. The overall quality of the systematic reviews was moderate while most of the trials had some concerns.

CONCLUSION

The study highlights a well-evidenced area in the safety of HPV vaccination with significant gaps in research on other key health interventions, particularly in non-healthcare settings. EGM suggests further research to evaluate the effectiveness of a broad range of preconception interventions, among adolescents and youth for improving long-term health outcomes.

Different dose series of human papillomavirus vaccine in young females: a pair-wise meta-analysis and network meta-analysis from randomized controlled trials

Objective

To investigate the application value of different dose of HPV vaccine in young females.

Data sources

The following databases were searched: Cochrane Library, PubMed, Embase, Web of Science, SINOMED, and Wanfang Data, from the establishment of the database to August 1st, 2022.

Study eligibility criteria

The inclusion criterias were: healthy young women younger than 25 years old as the research object, randomized controlled study as the research type, and the efficacy and safety of single-dose, two-dose or three-dose HPV vaccines as the intervention measures and research endpoints.

Study appraisal and synthesis methods

Meta-analysis was performed to analyze the protective effects of single-dose, 2-dose and 3-dose HPV vaccine series on young females.

Results

A total of eight eligible studies involving 16 publications were included. There is no difference in the immunogenicity between the 2-dose and 3-dose series within 12 months after the last dose of HPV vaccine. However, 3-dose series was better than the 2-dose series, which performed better than the single-dose vaccine, after 12 months. With respect to the prevention of HPV16/18 infection or HPV31/33/45 infection, the single-dose vaccine worked better than 2-dose or 3-dose series.

Conclusions

The present study showed that the immunogenicity of low-dose HPV vaccine was significantly less, but it reduced the risk of high-risk HPV infection. The low-dose HPV vaccine series may not offer a preventive effect on cervical lesions, though it needs to be further confirmed by additional studies.

HPV16/18 Antibody Responses After a Single Dose of Nonavalent HPV Vaccine

OBJECTIVES

A single dose of human papillomavirus (HPV) vaccine would simplify logistics and reduce costs of vaccination programs worldwide. We conducted a phase IIa trial to determine the stability of HPV type-specific antibody responses after a single dose of the nonavalent HPV vaccine, Gardasil9.

METHODS

Two hundred-and-one healthy 9 to 11-year-old girls and boys were enrolled at 2 centers in the United States to receive a prime dose of the nonavalent vaccine at baseline, a delayed dose at month 24, and an optional third dose at month 30. Blood samples were collected to measure HPV type-specific antibodies at baseline and at 6, 12, 18, 24, and 30 months after the prime dose. The primary outcomes were serum HPV16 and HPV18 antibody responses.

RESULTS

In both girls and boys, geometric mean concentrations of HPV16 and HPV18 antibodies increased at 6 months, declined between months 6 to 12, and then remained stable and high (at 20- and 10-times those at baseline for HPV16 and HPV18, respectively) throughout months 12, 18, and 24 (prebooster) visits. Both HPV16 and HPV18 antibody responses demonstrated anamnestic boosting effect at 30-months after the delayed (24-month) booster dose.

CONCLUSIONS

A single dose of the nonavalent HPV vaccine induced persistent and stable HPV16 and HPV18 antibody responses up to 24 months. This study contributes important immunogenicity data to inform feasibility of the single dose HPV vaccination paradigm. Further research is needed to assess the long-term antibody stability and individual clinical and public health benefit of the single dose schedule.

Immunogenicity and safety of a bivalent, adjuvant system 04-adjuvanted human papillomavirus vaccine in healthy female volunteers aged 15-25: a randomized, double-blind, phase III, noninferiority clinical trial

OBJECTIVE

Vaccination is proven to significantly reduce the risk of human papillomavirus (HPV)-related complications, especially cervical cancer. This study aimed to assess the immunogenicity and safety of the investigational bivalent HPV vaccine (16/18), named Papilloguard (Noyan Pajouhan Biopharma, Tehran, Iran), in comparison with the reference product (Cervarix, bivalent HPV vaccine (16/18) manufactured by GlaxoSmithKline, Rixensart, Belgium) in a three-dose regimen.

METHODS

This trial was a randomized, controlled, double-blind, phase III study of two HPV vaccines in healthy female volunteers aged 15-25. The primary endpoint was to test the noninferiority of Papilloguard (Noyan Pajouhan Biopharma) to Cervarix (GlaxoSmithKline) as measured by the geometric mean titer (GMT) ratios of HPV-16 and HPV-18 7 months after the first vaccination. Secondary endpoints were the proportion of local and systemic solicited and unsolicited events, and the number of females with seroconversion against HPV-16 and HPV-18 7 months after the first vaccination.

RESULTS

Out of 504 screened women, 218 were enrolled. Seven months after the first vaccination, GMT ratios of HPV-16 and HPV-18 were 0.59 and 0.93, respectively. The seroconversion rates of both Papilloguard (Noyan Pajouhan Biopharma) and Cervarix (GlaxoSmithKline) were more than 96%. Both vaccinated groups had a generally good profile of solicited and unsolicited adverse events (AEs). The most common AE was discomfort at the injection site, which was well tolerated.

CONCLUSION

The result analysis of this study supports the noninferiority of Papilloguard (Noyan Pajouhan Biopharma) to Cervarix (GlaxoSmithKline) in terms of safety and immunogenicity based on the GMT ratio. However, long-term comparative studies to evaluate the sustainability of GMT response and risk of cervical intraepithelial neoplasia grades 2-3 are needed.

Immunogenicity of a Two-Dose Human Papillomavirus Vaccine Schedule in HIV-Infected Adolescents with Immune Reconstitution

HIV-infected patients are at increased risk of human papillomavirus (HPV) acquisition and HPV-associated diseases. This study set out to determine whether a two-dose (2D) HPV vaccination schedule was sufficient in HIV-infected adolescents with immune reconstitution (IR) following antiretroviral treatment. Participants aged 9–15 years who had CD4 cell counts > 500 cells/mm³ and HIV-1 RNA < 40 copies/mL for at least one year were assigned to the 2D schedule, while older participants or those without IR received a three-dose (3D) schedule. Antibodies to HPV-16 and -18 were measured using a pseudovirion-based neutralization assay. A total of 96 subjects were enrolled; 31.3% and 68.7% received the 2D and 3D schedule, respectively. Of these, 66.7% and 57.6% of the 2D and 3D participants, respectively, were male. The seroconversion rates for HPV-16 and HPV-18 were 100% in all cases, except for HPV-18 in males who received the 3D schedule (97.4%). In males, the anti-HPV-16 geometric mean titers (GMTs) were 6859.3 (95% confidence interval, 4394.3–10,707.1) and 7011.1 (4648.8–10,573.9) in the 2D and 3D groups (p = 0.946), respectively, and the anti-HPV-18 GMTs were 2039.3 (1432.2–2903.8) and 2859.8 (1810.0–4518.4) in the 2D and 3D (p = 0.313) groups, respectively. In females, the anti-HPV-16 GMTs were 15,758.7 (8868.0–28,003.4) and 26,241.6 (16,972.7–40,572.3) in the 2D and 3D groups (p = 0.197), respectively, and the anti-HPV-18 GMTs were 5971.4 (3026.8–11,780.6) and 9993.1 (5950.8–16,781.1) in the 2D and 3D groups (p = 0.271), respectively. In summary, a 2D schedule is as immunogenic in young adolescents with IR as a 3D schedule in older subjects and those without IR.

Review of long-term immunogenicity following HPV vaccination: Gaps in current knowledge

The licensed HPV vaccines are highly efficacious and induce high levels of neutralizing antibody levels, the assumed mediators of protection. However, a correlate of protection against HPV is lacking, and the evidence is still limited as to long-term persistence of antibodies, especially following reduced dosing schedules. The World Health Organization (WHO) urges immunization of young girls as part of the strategy to eliminate cervical cancer, thus long-lasting protection is required. The current review describes long-term follow-up regarding vaccine-induced seropositivity and antibody level development following the different vaccines and dosing schedules. Implications and opportunities of long-term vaccine-induced immune responses are discussed, such as the gaps in monitoring of long-term immunogenicity, the possibilities of reduced dosing schedules, and the importance of evidence for durable immunity.

Vaccine effectiveness following routine immunization with bivalent HPV vaccine: Protection against incident genital HPV infections from a reduced-dosing schedule

Background

In the Netherlands, the bivalent human papillomavirus (HPV) vaccine has been offered to preadolescent girls via the National Immunization Program in a 2-dose schedule since 2014. The current study estimates vaccine effectiveness (VE) against HPV infections up to 4 years postvaccination among girls eligible for routine 2-dose immunization.

Methods

A cohort study (HAVANA2) was used in which participants annually filled out an online questionnaire and provided a vaginal self-sample for determination of HPV by the SPF10-LiPA25 assay, able to detect 25 HPV types. VE against incident type-specific infections and pooled outcomes was estimated by a Cox proportional hazards model with shared frailty between the HPV types.

Results

In total, 2027 girls were included in the study, 1098 (54.2%) of whom were vaccinated with 2 doses. Highest incidence rate was 5.0/1000 person-years (HPV-51) among vaccinated participants and 9.1/1000 person-years (HPV-74) among unvaccinated participants. Adjusted pooled VE was 84.0% (95% confidence interval [CI], 27.0%–96.5%) against incident HPV-16/18 infections and 86.5% (95% CI, 39.5%–97.08%) against cross-protective types HPV-31/33/45.

Conclusions

Four years postvaccination, 2 doses of bivalent HPV vaccine were effective in the prevention of incident HPV-16/18 infections and provided cross-protection to HPV-31/33/45. Our VE estimates rival those from 3-dose schedules, indicating comparable protection by 2-dose schedules.

Immunogenicity of 2 and 3 Doses of the Quadrivalent Human Papillomavirus Vaccine up to 120 Months Postvaccination: Follow-up of a Randomized Clinical Trial

Background

Several countries have implemented a 2-dose (2D) human papillomavirus (HPV) vaccination schedule for adolescents based on immunobridging studies. We compared immunogenicity of 2D vs 3-dose (3D) schedules of the quadrivalent vaccine (4vHPV) up to 10 years after the first dose.

Methods

Girls aged 9–13 years were randomized to receive 2D or 3D and were compared with women aged 16–26 receiving 3D at day 1 and months 7, 24, and 120 after the first dose. Antibody levels for HPV6/11/16/18 were evaluated using the competitive Luminex immunoassay (cLIA) and total immunoglobulin G assay. Geometric mean titers (GMTs) and seropositivity rates were compared between the different groups at different time points. Noninferiority of GMT ratios was defined as the lower bound of the 2-sided 95% confidence interval (CI) being greater than 0.5. Kinetics of antibody titers over time among study groups were examined.

Results

At 120 months, data from 35 2D girls, 38 3D girls, and 30 3D women were used for analyses. cLIA seropositivity rates were above 95% for all HPV vaccine types and all schedules, except HPV18, with the lowest seropositivity observed among 3D women (60.0%; 95% CI, 40.6%–77.3%). GMT ratios (cLIA) for both 2D and 3D girls were noninferior to 3 doses in women for HPV6/11/16/18. Trends were comparable between assays.

Conclusions

GMTs for HPV6/11/16/18 after 2D or 3D of 4vHPV in girls were noninferior to 3D in adult women up to 120 months postvaccination. This study demonstrates long-term immunogenicity of the 2D HPV vaccine schedule.

Effectiveness of HPV vaccine by age at vaccination and number of doses: protocol for a population-based matched case-control study

INTRODUCTION

In 2006, the first human papillomavirus (HPV) vaccine was approved by the Food and Drug Administration in the USA based on pre-licensure clinical trials that found it to be highly efficacious at preventing persistent infection and precancerous, high-grade cervical lesions (HGCLs) caused by viral types the vaccine protects against. However, the real-world effectiveness of HPV vaccines as used in clinical practice may be quite different from the efficacy found in pre-licensure clinical trials. More than 10 years have passed since the introduction of the vaccine programme. It is critical to determine if the full benefits of HPV are being realised in real-world settings.

METHODS AND ANALYSIS

The objectives of this study were to estimate the effectiveness of HPV vaccines as used in real-world clinical settings and to determine the degree to which the vaccine's effectiveness varies based on age at the time of immunisation and the number of doses received. The study will be a population-based, matched case-control study. Cases will be women with newly diagnosed HGCL associated with HPV types 16 and 18. Matched controls will be women with a normal Pap test result, matched individually to cases in a 2:1 ratio by age, a practice and date of testing. Medical records will be reviewed to determine dates of receipt of the HPV vaccine for all participants. We will use multivariate conditional logistic regression to control for potential confounders.

ETHICS AND DISSEMINATION

This protocol presents minimal risk to the subjects. This protocol has received approval from the Institutional Review Board of Yale University (HIC: 1502015308), and a Health Insurance Portability and Accountability Act (HIPAA) Waiver of Authorisation has been granted to allow investigators to recruit subjects for the study. Findings will be disseminated through peer-reviewed, open-access scientific journals and conference presentations.

Technological approaches to streamline vaccination schedules, progressing towards single-dose vaccines

Vaccines represent the most successful medical intervention in history, with billions of lives saved. Although multiple doses of the same vaccine are typically required to reach an adequate level of protection, it would be advantageous to develop vaccines that induce protective immunity with fewer doses, ideally just one. Single-dose vaccines would be ideal to maximize vaccination coverage, help stakeholders to greatly reduce the costs associated with vaccination, and improve patient convenience. Here we describe past attempts to develop potent single dose vaccines and explore the reasons they failed. Then, we review key immunological mechanisms of the vaccine-specific immune responses, and how innovative technologies and approaches are guiding the preclinical and clinical development of potent single-dose vaccines. By modulating the spatio-temporal delivery of the vaccine components, by providing the appropriate stimuli to the innate immunity, and by designing better antigens, the new technologies and approaches leverage our current knowledge of the immune system and may synergize to enable the rational design of next-generation vaccination strategies. This review provides a rational perspective on the possible development of future single-dose vaccines.

Progress in Vaccination of Prophylactic Human Papillomavirus Vaccine

The human papillomavirus (HPV) vaccine plays an important role in preventing a series of diseases caused by HPV. Recent studies have shown that as a primary prevention measure, it can considerably prevent HPV infection and HPV-associated cervical cancer. However, studies on the safety, efficacy, and coverage of the HPV vaccine remain insufficient, especially in developing countries. Therefore, in this review, we outlined the recent studies of the HPV vaccine in terms of immunogenicity, safety, efficacy, latest vaccination concepts, and strategies. This review may provide a theoretical basis for use of the HPV vaccine.

Scientific evidence supporting recommendations on the use of the 9-valent HPV vaccine in a 2-dose vaccine schedule in Australia

The Australian Technical Advisory Group on Immunisation (ATAGI) updated recommendations on the use of human papillomavirus (HPV) vaccines in the Australian Immunisation Handbook in 2018, regarding the use of the recently available 9-valent (9vHPV) vaccine, Gardasil 9, and a 2-dose schedule for young adolescents for HPV vaccines. This report provides an overview of the relevant scientific evidence that underpinned these updated recommendations. The 9vHPV vaccine includes 5 HPV types (HPV 31, 33, 45, 52 and 58) additional to the 4 that are also covered by the 4vHPV (Gardasil) vaccine (HPV 6,11,16,18). Accordingly, the 9vHPV vaccine is expected to prevent an additional 15% of cervical cancers and up to 20% of other HPV-related cancers. Non-inferior antibody responses after two 9vHPV vaccine doses given 6-12 months apart in girls and boys aged 9-14 years compared to women aged 16-26 years after three doses support the 2-dose schedule for adolescents of this age group. In clinical trials 9vHPV vaccine was well-tolerated with a similar safety profile to 4vHPV vaccine. The switch to 9vHPV vaccine and a 2-dose schedule is anticipated to improve public acceptability of the program and reduce HPV-related disease in the long-term.

Cost-effectiveness of 2-dose human papillomavirus vaccination for 12-year-old girls in Zhejiang Province: implications for China's expanded program on immunization

BACKGROUND

The high cost and insufficient supply of HPV vaccines have substantially slowed their implementation in lower-income countries. This study aimed to assess the incremental cost-effectiveness of two doses of human papillomavirus (HPV) vaccination (bivalent 16/18 vaccine; 2vHPV) compared to a no-vaccination scenario and a three-dose scenario in one province in China.

METHODS

A static Markov model was used to model a lifetime cohort of 100,000 girls aged 12 years at the start of vaccination. A two-dose vaccination schedule was assumed to be non-inferior to a three-dose schedule in terms of vaccine efficacy, and both vaccination schemes were assumed to provide lifelong protection. Incremental costs, health effects and incremental cost-effectiveness ratios were used to measure the outcomes when comparing the different strategies.

RESULTS

Compared to no vaccination, the incremental cost-effectiveness ratio (Chinese yuan per quality-adjusted life year) of the two-dose vaccination strategy is 12,472, and the 2-dose strategy is calculated to be cost saving relative to the 3-dose vaccination strategy.

CONCLUSIONS

Introducing the 2vHPV vaccine would be highly cost effective at a per-dose vaccine price of CNY 500, which has implications for cervical cancer control in China and other resource-limited countries.

Human Papillomavirus Vaccination Schedule: Adherence Among Commercially Insured Adolescents and Young Adults in the United States, 2011–2017

Objectives. To determine rates of human papillomavirus (HPV) vaccine adherence to the 2011 and 2016 Advisory Committee for Immunization Practices (ACIP) recommendations in the United States.

Methods. We conducted a retrospective cohort study by using the 2011 to 2017 Marketscan data for beneficiaries aged 9 to 26 years who had at least 1 claim for HPV vaccination between January 1, 2011, and January 1, 2017. According to the 2011 ACIP recommendation, adherence is defined as 30 to 90 days between the first and second vaccination and 168 to 212 days between the first and third vaccination. According to the 2016 recommendation, preadolescents are classified as adherent if they had 2 claims of vaccination within 168 to 212 days. We calculated proportions of completion and adherence by recommendation.

Results. Among patients classified under the 2011 ACIP recommendation (n = 2 164 096), 8.3% completed all 3 doses of the vaccine series. Of those who completed, 69.6% were considered adherent to the recommended schedule. Completion and adherence increased to 9.6% and 70.8%, respectively, among patients who were classified under the 2016 ACIP recommendation.

Conclusions. Simpler recommendations lead to better adherence to the HPV vaccination schedule.

Selective Persistence of HPV Cross-Neutralising Antibodies following Reduced-Dose HPV Vaccine Schedules

The duration of cross-neutralising antibody responses (cross-NAb) following HPV immunisation is unknown. We compared cross-NAb responses in cohort of girls who were either unimmunised or had received immunisation with one, two or three doses of 4vHPV (Gardasil^®, Merck Inc., Kenilworth, NJ, USA) six years earlier, before and one month after a booster dose of 2vHPV (Cervarix^®, GSK, Brentford, UK). NAb to potentially cross-reactive HPV genotypes 31, 33, 45, 52 and 58 were measured using a HPV pseudovirion-based neutralisation assay. Girls who had previously received at least one dose of 4vHPV had significantly higher NAb titres for HPV31 when compared with unimmunised girls, whereas no difference in NAb titre was observed for four other genotypes (33, 45, 52 and 58). Following a single further immunisation with 2vHPV, NAb titres to each of the five tested HPV genotypes were comparable for girls who previously received one, two or three doses of 4vHPV, and were significantly higher than for previously unimmunised girls. Immunisation with one, two or three doses of 4vHPV induced NAb to HPV31 that persisted for six years, but there was no persistence of NAb to HPV33, 45, 52 or 58. Our results suggest that one or two doses of 4vHPV may provide long-term protection against HPV31.

Comparison of different human papillomavirus (HPV) vaccine types and dose schedules for prevention of HPV-related disease in females and males

BACKGROUND

Uptake of human papillomavirus (HPV) vaccine remains low in many countries, although the bivalent and quadrivalent HPV vaccines given as a three-dose schedule are effective in the prevention of precancerous lesions of the cervix in women. Simpler immunisation schedules, such as those with fewer doses, might reduce barriers to vaccination, as may programmes that include males.

OBJECTIVES

To evaluate the efficacy, immunogenicity, and harms of different dose schedules and different types of HPV vaccines in females and males.

SEARCH METHODS

We conducted electronic searches on 27 September 2018 in Ovid MEDLINE, the Cochrane Central Register of Controlled Trials (CENTRAL) (in the Cochrane Library), and Ovid Embase. We also searched the WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov (both 27 September 2018), vaccine manufacturer websites, and checked reference lists from an index of HPV studies and other relevant systematic reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with no language restriction. We considered studies if they enrolled HIV-negative males or females aged 9 to 26 years, or HIV-positive males or females of any age.

DATA COLLECTION AND ANALYSIS

We used methods recommended by Cochrane. We use the term 'control' to refer to comparator products containing an adjuvant or active vaccine and 'placebo' to refer to products that contain no adjuvant or active vaccine. Most primary outcomes in this review were clinical outcomes. However, for comparisons comparing dose schedules, the included RCTs were designed to measure antibody responses (i.e. immunogenicity) as the primary outcome, rather than clinical outcomes, since it is unethical to collect cervical samples from girls under 16 years of age. We analysed immunogenicity outcomes (i.e. geometric mean titres) with ratios of means, clinical outcomes (e.g. cancer and intraepithelial neoplasia) with risk ratios or rate ratios and, for serious adverse events and deaths, we calculated odds ratios. We rated the certainty of evidence with GRADE.

MAIN RESULTS

We included 20 RCTs with 31,940 participants. The length of follow-up in the included studies ranged from seven months to five years. Two doses versus three doses of HPV vaccine in 9- to 15-year-old females Antibody responses after two-dose and three-dose HPV vaccine schedules were similar after up to five years of follow-up (4 RCTs, moderate- to high-certainty evidence). No RCTs collected clinical outcome data. Evidence about serious adverse events in studies comparing dose schedules was of very low-certainty owing to imprecision and indirectness (three doses 35/1159; two doses 36/1158; 4 RCTs). One death was reported in the three-dose group (1/898) and none in the two-dose group (0/899) (low-certainty evidence). Interval between doses of HPV vaccine in 9- to 14-year-old females and males Antibody responses were stronger with a longer interval (6 or 12 months) between the first two doses of HPV vaccine than a shorter interval (2 or 6 months) at up to three years of follow-up (4 RCTs, moderate- to high-certainty evidence). No RCTs collected data about clinical outcomes. Evidence about serious adverse events in studies comparing intervals was of very low-certainty, owing to imprecision and indirectness. No deaths were reported in any of the studies (0/1898, 3 RCTs, low-certainty evidence). HPV vaccination of 10- to 26-year-old males In one RCT there was moderate-certainty evidence that quadrivalent HPV vaccine, compared with control, reduced the incidence of external genital lesions (control 36 per 3081 person-years; quadrivalent 6 per 3173 person-years; rate ratio 0.16, 95% CI 0.07 to 0.38; 6254 person-years) and anogenital warts (control 28 per 2814 person-years; quadrivalent 3 per 2831 person-years; rate ratio 0.11, 95% CI 0.03 to 0.38; 5645 person-years). The quadrivalent vaccine resulted in more injection-site adverse events, such as pain or redness, than control (537 versus 601 per 1000; risk ratio (RR) 1.12, 95% CI 1.06 to 1.18, 3895 participants, high-certainty evidence). There was very low-certainty evidence from two RCTs about serious adverse events with quadrivalent vaccine (control 12/2588; quadrivalent 8/2574), and about deaths (control 11/2591; quadrivalent 3/2582), owing to imprecision and indirectness. Nonavalent versus quadrivalent vaccine in 9- to 26-year-old females and males Three RCTs were included; one in females aged 9- to 15-years (n = 600), one in females aged 16- to 26-years (n = 14,215), and one in males aged 16- to 26-years (n = 500). The RCT in 16- to 26-year-old females reported clinical outcomes. There was little to no difference in the incidence of the combined outcome of high-grade cervical epithelial neoplasia, adenocarcinoma in situ, or cervical cancer between the HPV vaccines (quadrivalent 325/6882, nonavalent 326/6871; OR 1.00, 95% CI 0.85 to 1.16; 13,753 participants; high-certainty evidence). The other two RCTs did not collect data about clinical outcomes. There were slightly more local adverse events with the nonavalent vaccine (905 per 1000) than the quadrivalent vaccine (846 per 1000) (RR 1.07, 95% CI 1.05 to 1.08; 3 RCTs, 15,863 participants; high-certainty evidence). Comparative evidence about serious adverse events in the three RCTs (nonavalent 243/8234, quadrivalent 192/7629; OR 0.60, 95% CI 0.14 to 2.61) was of low certainty, owing to imprecision and indirectness. HPV vaccination for people living with HIV Seven RCTs reported on HPV vaccines in people with HIV, with two small trials that collected data about clinical outcomes. Antibody responses were higher following vaccination with either bivalent or quadrivalent HPV vaccine than with control, and these responses could be demonstrated to have been maintained for up to 24 months in children living with HIV (low-certainty evidence). The evidence about clinical outcomes and harms for HPV vaccines in people with HIV is very uncertain (low- to very low-certainty evidence), owing to imprecision and indirectness.

AUTHORS' CONCLUSIONS

The immunogenicity of two-dose and three-dose HPV vaccine schedules, measured using antibody responses in young females, is comparable. The quadrivalent vaccine probably reduces external genital lesions and anogenital warts in males compared with control. The nonavalent and quadrivalent vaccines offer similar protection against a combined outcome of cervical, vaginal, and vulval precancer lesions or cancer. In people living with HIV, both the bivalent and quadrivalent HPV vaccines result in high antibody responses. For all comparisons of alternative HPV vaccine schedules, the certainty of the body of evidence about serious adverse events reported during the study periods was low or very low, either because the number of events was low, or the evidence was indirect, or both. Post-marketing surveillance is needed to continue monitoring harms that might be associated with HPV vaccines in the population, and this evidence will be incorporated in future updates of this review. Long-term observational studies are needed to determine the effectiveness of reduced-dose schedules against HPV-related cancer endpoints, and whether adopting these schedules improves vaccine coverage rates.

Long-term Cross-reactivity Against Nonvaccine Human Papillomavirus Types 31 and 45 After 2- or 3-Dose Schedules of the AS04-Adjuvanted Human HPV-16/18 Vaccine

This analysis focused on long-term cross-reactive immunogenicity against nonvaccine human papillomavirus (HPV) types 31 and 45 following 2 doses of AS04-adjuvanted HPV-16/18 vaccine in girls aged 9-14 years or following 3 doses in women aged 15-25 years, for up to 3 years (HPV-070 study) and up to 5 years (HPV-048 study) after the first vaccination. Both schedules elicited antibodies against HPV-31 and HPV-45 up to 5 years after first dose. The antibody concentration was similar in young girls as compared to women. Specific CD4+ T-cell and B-cell responses to HPV-31 and HPV-45 at month 36 were similar across groups. Clinical trials registration: NCT01381575 and NCT00541970.

A prospective, single-arm, open-label, non-randomized, phase IIa trial of a nonavalent prophylactic HPV vaccine to assess immunogenicity of a prime and deferred-booster dosing schedule among 9-11 year-old girls and boys - clinical protocol

BACKGROUND

Human papillomavirus (HPV) vaccines are indicated for the prevention of cancers and genital warts caused by vaccine-covered HPV types. Although the standard regimen requires a two or three-dose vaccine series, there is emerging data suggesting that a single dose of the bivalent or quadrivalent HPV vaccine generates persistently positive antibody titers. No similar data is yet available for the nonavalent HPV vaccine, currently the only HPV vaccine available in the United States. The overall objective of our study is to assess the stability and kinetics of antibody titers for 24 months following a single dose of the nonavalent HPV vaccine among preteen girls and boys.

METHODS

This is a prospective, single-arm, open-label, non-randomized, Phase IIa trial among 9-11 year-old girls and boys to determine the immunogenicity after a single dose of the nonavalent HPV vaccine (GARDASIL® 9) over 24 months, with a deferred booster dose at 24 months and an optional booster at 30 months after the first dose. Participants provide blood specimens at 6, 12, 18, 24, and 30 months after the first dose. Serologic geometric mean titers (GMT) of the nine vaccine types (HPV 16/18/ 6/11/31/33/45/52/58) will be measured at each time point. The primary objective is to determine the stability of type-specific serologic GMT of HPV16 and HPV18 between the 6- vs. 12-month, 12- vs. 18-month, and 18- vs. 24-month visits. Secondary objectives are to determine the stability of type-specific serologic GMT of the other HPV types (HPV 6/11/31/33/45/52/58) between the visits and to assess safety and reactogenicity after each vaccine dose.

DISCUSSION

Single dose HPV vaccination could simplify the logistics and reduce costs of HPV vaccination in the US and across the world. This study will contribute important immunogenicity data on the stability and kinetics of type-specific antibody titers and inform feasibility of the single dose HPV vaccination paradigm.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02568566 . Registered on October 6, 2015.

Persistence of Immunity When Using Different Human Papillomavirus Vaccination Schedules and Booster-Dose Effects 5 Years After Primary Vaccination

Background

There are limited data regarding the duration of immunity induced by different human papillomavirus (HPV) vaccination schedules and the immunogenicity of a booster dose of both bivalent HPV vaccine (bHPV) or quadrivalent HPV vaccine (qHPV).

Methods

Follow-up of a nonrandomized clinical trial to evaluate the 5-year antibody persistence of the bHPV in girls (age, 9-10 years) and women (age, 18-24 years). Noninferiority of the 2-dose versus 3-dose schedule among girls was evaluated at months 54 (n = 639) and 64 (n = 990). Girls vaccinated with a 2-dose schedule of bHPV or qHPV received a booster dose of either vaccine at month 61. Immunogenicity was measured using a virus-like particle-based enzyme-linked immunosorbent assay. Geometric mean titers (GMTs) for HPV16/18 were estimated after stratification by vaccination schedule and age group.

Results

At months 54 and 64, the 2-dose schedule remained noninferior to the 3-dose schedule. GMTs remained above natural infection levels across all age groups up to 64 months. After the booster, anti-HPV16/18 GMTs increased exponentially with the same pattern, regardless of vaccine administered. No safety concerns were identified with the booster dose.

Conclusions

A 2-dose schedule is highly immunogenic in girls, suggesting a high immune memory. Thus, a booster dose is likely to be unprofitable, considering the low global immunization coverage.

Clinical Trials Registration

NCT01717118.

Improving Human Papilloma Virus Vaccination Rates at an Urban Pediatric Primary Care Center

Introduction

Despite compelling evidence regarding its safety and efficacy, human papilloma virus vaccination rates remain low nationally with high rates of missed vaccination opportunities. Provider recommendation is the most important factor in determining vaccine approval by families; yet, studies show that providers are hesitant to strongly recommend vaccination, especially at younger ages. We hypothesized that educational and quality improvement interventions targeting our clinical team would decrease rates of missed opportunities to vaccinate patients aged 11-13 years and improve vaccination rates among patients aged 9-10 years old.

Methods

This quality improvement project took place at an urban, academic pediatric primary care center in north Philadelphia, which serves as the medical home for over 22,000 patients. A multidisciplinary team performed a series of planned sequential interventions to improve human papilloma virus vaccination rates. The electronic health records of children aged 9-13 who presented to our center from September 2014 through December 2015 were queried. Statistical process control charts and established rules for detecting special cause variation were applied.

Results

Rates of missed opportunities to vaccinate 11- to 13-year-old patients decreased from 63% to 18% during the intervention period. Rates of immunization of 9- to 10-year-old patients increased from 56% to 84% during the intervention period.

Conclusion

This low-cost, multifaceted, interdisciplinary quality improvement project resulted in a decrease in missed opportunities to vaccinate among children aged 11-13 years old and improved the vaccination rates of 9-10 year olds. Ongoing interventions are needed to sustain these efforts and to ensure timely vaccine series completion.

Current Status of Human Papillomavirus Infection and Introduction of Vaccination to the National Immunization Program in Korea: an Overview

Human Papillomavirus (HPV) infection is the most common sexually transmitted infection and is associated with the development of cervical cancer. The purpose of this report is to provide the literature evidences on selecting the HPV vaccine for national immunization program (NIP) in Korea. To complete these tasks, we reviewed domestic and foreign literature on the current status of HPV infection, efficacy and effectiveness of HPV vaccine, safety of vaccine and cost effectiveness analysis of vaccination business. Given that the median age of first sexual intercourse is continuing to fall, this may have serious implications for HPV infection and cervical cancer incidence at the age of 20s. The World Health Organization recommends that the HPV vaccination should be included in the NIP being implemented in each country. Both the bivalent and quadrivalent vaccines have a 90% or greater preventive efficacy on cervical intraepithelial lesion 2-3 and cervical cancer by the HPV 16 or HPV 18. In the future, if HPV vaccination rate as part of NIP increases, it is expected that the incidence of HPV infection, genital warts, and cervical precancerous lesions will be decreased in the vaccination age group. Therefore, in order to increase the HPV vaccination rate at this point in Korea, social consensus and efforts such as the introduction and promotion of HPV vaccine to the NIP according to appropriate cost-effectiveness analysis are required.

[Alternative HPV vaccination schedules in Latin America]

In 2008, the first HPV vaccination program in Latin America started in Panama, targeting girls aged 10-11 years with a 3-dose vaccine schedule, an initiative that was to be followed by other Latin American countries after local feasibility and population acceptability evaluations were completed. A 3-dose vaccine regimen over six months was originally chosen for HPV vaccines, copying the Hepatitis B vaccine schedule (0, 1-2, 6 months). Alternative vaccine schedules have been proposed afterwards based on: i) noninferior immunogenicity or immune response levels compared to those at which clinical efficacy has been proven (i.e., those observed in a 3-dose HPV vaccine schedule in women aged 15-26), and, ii) proven efficacy in clinical trials and/or effectiveness among women who were provided less than three doses due to a lack of adherence to a 3-dose vaccine schedule. In 2014, based on the available evidence and the potential increase in coverage by expansion of vaccination target groups, particularly in low and middle income countries (LMIC), the World Health Organization recommended a 2-dose schedule with at least a 6-month interval between doses for females up to 15 years of age and a 3-dose schedule for older women. More recently, it has been suggested that 1-dose HPV vaccination schemes may provide enough protection against HPV infection and may speed up the introduction of HPV vaccination in LMIC, where most needed.

Acceptability of two- versus three-dose human papillomavirus vaccination schedule among providers and mothers of adolescent girls: a mixed-methods study in five countries

PURPOSE

The World Health Organization revised its human papillomavirus (HPV) vaccination recommendations to include a two (2-) dose schedule for girls aged ≤ 15 years. We investigated acceptability of 2- versus 3-dose schedule among adolescent vaccination providers and mothers of adolescent girls in five countries.

METHODS

Adolescent vaccination providers (N = 151) and mothers of adolescent girls aged 9-14 years (N = 118) were recruited from Argentina, Malaysia, South Africa, South Korea, and Spain. We assessed providers' preference for a 2- versus 3-dose HPV vaccination schedule via quantitative surveys. Mothers' attitudes towards a 2-dose schedule were assessed through focus group discussions.

RESULTS

Most adolescent providers preferred a 2- over a 3-dose HPV vaccination schedule (overall: 74%), with preference ranging from 45.2% (South Africa) to 90.0% (South Korea). Lower cost, fewer clinic visits, and higher series completion were commonly cited reasons for 2-dose preference among providers and mothers. Safety and efficacy concerns were commonly cited barriers to accepting a 2-dose HPV vaccination schedule among providers and mothers. Mothers generally accepted the reduced schedule, however requested further information from a trusted source.

CONCLUSIONS

Adolescent vaccination providers and mothers preferred the 2-dose over 3-dose HPV vaccination schedule. Acceptability of a 2-dose HPV vaccination could be improved with additional information to providers and mothers on HPV vaccination safety and efficacy.

Immunogenicity of HPV prophylactic vaccines: Serology assays and their use in HPV vaccine evaluation and development

When administered as standard three-dose schedules, the licensed HPV prophylactic vaccines have demonstrated extraordinary immunogenicity and efficacy. We summarize the immunogenicity of these licensed vaccines and the most commonly used serology assays, with a focus on key considerations for one-dose vaccine schedules. Although immune correlates of protection against infection are not entirely clear, both preclinical and clinical evidence point to neutralizing antibodies as the principal mechanism of protection. Thus, immunogenicity assessments in vaccine trials have focused on measurements of antibody responses to the vaccine. Non-inferiority of antibody responses after two doses of HPV vaccines separated by 6 months has been demonstrated and this evidence supported the recent WHO recommendations for two-dose vaccination schedules in both boys and girls 9-14 years of age. There is also some evidence suggesting that one dose of HPV vaccines may provide protection similar to the currently recommended two-dose regimens but robust data on efficacy and immunogenicity of one-dose vaccine schedules are lacking. In addition, immunogenicity has been assessed and reported using different methods, precluding direct comparison of results between different studies and vaccines. New head-to-head vaccine trials evaluating one-dose immunogenicity and efficacy have been initiated and an increase in the number of trials relying on immunobridging is anticipated. Therefore, standardized measurement and reporting of immunogenicity for the up to nine HPV types targeted by the current vaccines is now critical. Building on previous HPV serology assay standardization and harmonization efforts initiated by the WHO HPV LabNet in 2006, new secondary standards, critical reference reagents and testing guidelines will be generated as part of a new partnership to facilitate harmonization of the immunogenicity testing in new HPV vaccine trials.

Safety and Immunogenicity of the HPV-16/18 AS04-adjuvanted Vaccine in 4-6-year-old Girls: Results to Month 12 From a Randomized Trial

BACKGROUND

The burden of cervical cancer caused by human papillomavirus (HPV) is high in Latin America. The suboptimal HPV vaccination coverage in adolescents could be improved by pediatric immunization. HPV vaccination has not yet been reported in girls <9 years of age.

METHODS

This ongoing phase III, controlled, randomized, single-blind, multicenter study conducted in Colombia, Mexico and Panama (NCT01627561) evaluated the safety and immunogenicity of AS04-HPV-16/18 vaccine in 4-6-year-old girls. Healthy girls (randomized 1:1) received either 2 doses of AS04-HPV-16/18 vaccine (HPV group, N=74) or 1 dose of each measles-mumps-rubella and diphtheria-tetanus-acellular-pertussis vaccines (control group, N=74) 6 months apart. We report the safety and serum anti-HPV-16 and anti-HPV-18 antibodies (measured by enzyme-linked immunosorbent assay) up to 6 months postvaccination, that is, month (M) 12.

RESULTS

Injection site pain was the most frequently reported solicited local symptom in HPV vaccinees. The incidence of other solicited and unsolicited symptoms after each vaccination was similar between the HPV and control group. Until M12, 1 girl in the HPV group and 2 in the control group reported serious adverse events; all serious adverse events were assessed as unrelated to study vaccines. No potential immune-mediated diseases were identified. All girls seroconverted for both antigens after 2 doses of AS04-HPV-16/18. In initially seronegative girls, anti-HPV-16 geometric mean concentrations were 20080.0 enzyme-linked immunosorbent assay units (EU)/mL at M7 and 3246.5 EU/mL at M12; anti-HPV-18 geometric mean concentrations were 10621.8 EU/mL at M7 and 1216.6 EU/mL at M12.

CONCLUSIONS

Two-dose vaccination with AS04-HPV-16/18 was well tolerated and induced adequate antibody responses in 4-6-year-old girls.

Characterization of Immunoglobulin A/G Responses During 3 Doses of the Human Papillomavirus-16/18 ASO4-Adjuvanted Vaccine

BACKGROUND

Individuals receiving the human papillomavirus (HPV) vaccine develop high levels of circulating neutralizing antibodies. However, data about antibody responses in the cervix are limited.

METHODS

This study was designed to describe the course of IgA/IgG responses in cervical secretions and in serum after intramuscular administration of the HPV16/18 AS04-adjuvant vaccine. An enzyme-linked immunosorbent assay for detection of IgA and IgG anti-HPV-VLP was developed for this purpose.

RESULTS

Immunoglobulin G seroconversion after the second dose was observed in 100% of the participants and remained 1 month after the third dose. Regarding IgG reactivity in cervical secretions, conversion was observed in 85% of women after the final dose. Immunoglobulin A seroconversion was observed in 76.7% of women after the third dose. Lower levels of IgA were detected in the cervical mucus (28.3%) and decreased to 23.3% after the last dose. Comparing local and systemic IgG responses, positivity in both serum and cervical samples was observed in 85%, whereas in 15% only, the serum was IgG antibody positive. A weak agreement between local and systemic IgA responses was observed. Only 18.3% of participants were local and systemic IgA positive, 58.4% were positive only in serum, 5% were positive only in the cervix, and 18.3% were both local and systemic IgA antibody negative.

CONCLUSIONS

After the third vaccination, there is a strong agreement between cervical and systemic IgG antibody responses and a weak agreement between cervical and systemic IgA antibody responses. The induction of IgA antibodies seems to be secondary to that of IgG antibodies in response to HPV intramuscular vaccination.

Primary Prevention of Cervical Cancer: American Society of Clinical Oncology Resource-Stratified Guideline

PURPOSE

To provide resource-stratified (four tiers), evidence-based recommendations on the primary prevention of cervical cancer globally.

METHODS

The American Society of Clinical Oncology convened a multidisciplinary, multinational panel of oncology, obstetrics/gynecology, public health, cancer control, epidemiology/biostatistics, health economics, behavioral/implementation science, and patient advocacy experts. The Expert Panel reviewed existing guidelines and conducted a modified ADAPTE process and a formal consensus-based process with additional experts (consensus ratings group) for one round of formal ratings.

RESULTS

Existing sets of guidelines from five guideline developers were identified and reviewed; adapted recommendations formed the evidence base. Five systematic reviews, along with cost-effectiveness analyses, provided evidence to inform the formal consensus process, which resulted in agreement of ≥ 75%.

RECOMMENDATIONS

In all resource settings, two doses of human papillomavirus vaccine are recommended for girls age 9 to 14 years, with an interval of at least 6 months and possibly up to 12 to 15 months. Individuals with HIV positivity should receive three doses. Maximal and enhanced settings: if girls are age ≥ 15 years and received their first dose before age 15 years, they may complete the series; if no doses were received before age 15 years, three doses should be administered; in both scenarios, vaccination may be through age 26 years. Limited and basic settings: if sufficient resources remain after vaccinating girls age 9 to 14 years, girls who received one dose may receive additional doses between age 15 and 26 years. Maximal, enhanced, and limited settings: if ≥ 50% coverage in the priority female target population, sufficient resources, and cost effectiveness, boys may be vaccinated to prevent other noncervical human papillomavirus-related cancers and diseases. Basic settings: vaccinating boys is not recommended.

It is the view of the American Society of Clinical Oncology that health care providers and health care system decision makers should be guided by the recommendations for the highest stratum of resources available. The guideline is intended to complement but not replace local guidelines.

Sustained Immunogenicity of 2-dose Human Papillomavirus 16/18 AS04-adjuvanted Vaccine Schedules in Girls Aged 9-14 Years: A Randomized Trial

Background.

We previously reported the noninferiority 1 month after the last dose of 2-dose human papillomavirus 16/18 AS04-adjuvanted (AS04-HPV-16/18) vaccine schedules at months 0 and 6 (2D_M0,6) and months 0 and 12 (2D_M0,12) in girls aged 9–14 years compared with a 3-dose schedule at months 0, 1, and 6 (3D_M0,1,6) in women aged 15–25 years. Here, we report the results at study end (month 36 [M36]).

Methods.

Girls were randomized 1:1 and received 2 vaccine doses either 6 months (2D_M0,6) or 12 months apart (2D_M0,12); women received 3 doses at months 0, 1, and 6 (3D_M0,1,6). Endpoints included noninferiority of HPV-16/18 antibodies for 2D_M0,6 versus 3D_M0,1,6; 2D_M0,12 versus 3D_M0,1,6; and 2D_M0,12 versus 2D_M0,6; and assessment of neutralizing antibodies, T cells, B cells, and safety.

Results.

At M36, the 2D_M0,6 and 2D_M0,12 schedules remained noninferior to the 3D_M0,1,6 schedule in terms of seroconversion rates and 3D/2D geometric mean titers for anti-HPV-16 and anti-HPV-18. All schedules elicited sustained immune responses up to M36.

Conclusions.

Both 2-dose schedules in young girls remained noninferior to the 3-dose schedule in women up to study conclusion at M36. The AS04-HPV-16/18 vaccine administered as a 2-dose schedule was immunogenic and well tolerated in young girls.

Cost-effectiveness of human papillomavirus vaccination in Germany

BACKGROUND

The aim of this study was to assess the cost-effectiveness of human papillomavirus (HPV) vaccination in addition to the current cervical cancer screening programme in Germany using a dynamic transmission model.

METHODS

Based on a mathematical model simulating the transmission dynamics and the natural history of HPV infection and associated diseases (cervical intraepithelial neoplasia, cervical cancer, and genital warts), we estimated the epidemiological and economic consequences of HPV vaccination with both the quadrivalent and bivalent vaccines. In our base case analysis, we assessed the cost-effectiveness of vaccinating 12-year-old girls with a 3-dose schedule. In sensitivity analysis, we also evaluated the use of a 2-dose schedule and assessed the impact of vaccinating boys.

RESULTS

From a health care payer perspective, incremental cost-effectiveness ratios (ICERs) of a 3-dose schedule were €34,249 per quality-adjusted life year (QALY) for the bivalent and €14,711 per QALY for the quadrivalent vaccine. Inclusion of indirect costs decreased ICERs by up to 40%. When adopting a health care payer perspective, ICERs of a 2-dose approach decreased to €19,450 per QALY for the bivalent and to €3645 per QALY for the quadrivalent vaccine. From a societal perspective, a 2-dose approach using the quadrivalent vaccine was a cost-saving strategy while using the bivalent vaccine resulted in an ICER of €13,248 per QALY. Irrespective of the perspective adopted, additional vaccination of boys resulted in ICERs exceeding €50,000 per QALY, except for scenarios with low coverage (20%) in girls.

CONCLUSIONS

Our model results suggest that routine HPV vaccination of 12-year-old girls with three doses is likely to be cost-effective in Germany. Due to the additional impact on genital warts, the quadrivalent vaccine appeared to be more cost-effective than the bivalent vaccine. A 2-dose schedule of the quadrivalent vaccine might even lead to cost savings when adopting a societal perspective. The cost-effectiveness of additional vaccination of boys was highly dependent on the coverage in girls.

Timing of two versus three doses of quadrivalent HPV vaccine and associated effectiveness against condyloma in Sweden: a nationwide cohort study

OBJECTIVE

To assess incidence of condyloma after two doses of quadrivalent human papillomavirus (qHPV) vaccine, by time since first vaccine dose, in girls and women initiating vaccination before age 20 years.

DESIGN

Register-based nationwide open cohort study.

SETTING

Sweden.

PARTICIPANTS

Girls and women initiating qHPV vaccination before age 20 years between 2006 and 2012. The study cohort included 264 498 girls, of whom 72 042 had received two doses of qHPV vaccine and 185 456 had received all three doses.

MAIN OUTCOME MEASURE

Incidence rate ratios (IRRs) of condyloma estimated by time between first and second doses of qHPV in months (m) and age at vaccination, adjusted for attained age.

RESULTS

For girls first vaccinated with two doses before the age of 17 years, the IRR of condyloma for 0-3 months between the first and second doses was 1.96 (95% CI 1.43 to 2.68) as compared with the standard three-dose schedule. The IRRs were 1.27 (95% CI 0.63 to 2.58) and 4.36 (95% CI 2.05 to 9.28) after receipt of two doses with 4-7 months and 8+ months between doses, respectively. For women first vaccinated after the age of 17 years, vaccination with two doses of qHPV vaccine and 0-3 months between doses was associated with an IRR of 2.12 (95% CI 1.62 to 2.77). For an interval of 4-7 months between doses, the IRR did not statistically significantly differ to the standard three-dose schedule (IRR=0.81, 95% CI 0.36 to 1.84). For women with 8+ months between dose 1 and dose 2 the IRR was 3.16 (95% CI 1.40 to 7.14).

CONCLUSION

A two-dose schedule for qHPV vaccine with 4-7 months between the first and second doses may be as effective against condyloma in girls and women initiating vaccination under 20 years as a three-dose schedule. Results from this nationwide study support immunogenicity data from clinical trials.

Primary Immunization of Human Papillomavirus Vaccine in the Pediatric Population: What Is the Verdict Now?

The safety and efficacy of a 2-dose series for the human papillomavirus vaccines rather than a 3-dose series in older children has not been well defined. This article reviews the literature summarizing the use of all 3 HPV vaccines (2vHPV, 4vHPV, 9vHPV) as a 2-dose series for females and 4vHPV and 9vHPV for males younger than 15 years. Six prospective trials evaluating immunogenicity of a 2-dose series of 2vHPV and/or 4vHPV, as well as an ongoing prospective clinical trial for 9vHPV, are discussed. The 2-dose series with Gardasil 9^® in both males and females ages 9 to 14 years appears to be the most widely accepted recommendation. The exact time schedule between the 2 vaccines varies among studies, but it seems that they should be separated by 6 to 12 months. Federal and world-wide organizations' (ie, Centers for Disease Control and Prevention, Food and Drug Administration, and World Health Organization) opinions and recommendations on the appropriate scheduling of the vaccines are also highlighted.

Health economic evaluation of Human Papillomavirus vaccines in women from Venezuela by a lifetime Markov cohort model

Background

Cervical cancer (CC) and genital warts (GW) are a significant public health issue in Venezuela. Our objective was to assess the cost-effectiveness of the two available vaccines, bivalent and quadrivalent, against Human Papillomavirus (HPV) in Venezuelan girls in order to inform decision-makers.

Methods

A previously published Markov cohort model, informed by the best available evidence, was adapted to the Venezuelan context to evaluate the effects of vaccination on health and healthcare costs from the perspective of the healthcare payer in an 11-year-old girls cohort of 264,489. Costs and quality-adjusted life years (QALYs) were discounted at 5%. Eight scenarios were analyzed to depict the cost-effectiveness under alternative vaccine prices, exchange rates and dosing schemes. Deterministic and probabilistic sensitivity analyses were performed.

Results

Compared to screening only, the bivalent and quadrivalent vaccines were cost-saving in all scenarios, avoiding 2,310 and 2,143 deaths, 4,781 and 4,431 CCs up to 18,459 GW for the quadrivalent vaccine and gaining 4,486 and 4,395 discounted QALYs respectively. For both vaccines, the main determinants of variations in the incremental costs-effectiveness ratio after running deterministic and probabilistic sensitivity analyses were transition probabilities, vaccine and cancer-treatment costs and HPV 16 and 18 distribution in CC cases. When comparing vaccines, none of them was consistently more cost-effective than the other. In sensitivity analyses, for these comparisons, the main determinants were GW incidence, the level of cross-protection and, for some scenarios, vaccines costs.

Conclusions

Immunization with the bivalent or quadrivalent HPV vaccines showed to be cost-saving or cost-effective in Venezuela, falling below the threshold of one Gross Domestic Product (GDP) per capita (104,404 VEF) per QALY gained. Deterministic and probabilistic sensitivity analyses confirmed the robustness of these results.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4064-7) contains supplementary material, which is available to authorized users.

Cost-effectiveness analysis of AS04-adjuvanted human papillomavirus 16/18 vaccine compared with human papillomavirus 6/11/16/18 vaccine in the Philippines, with the new 2-dose schedule

Cervical cancer (CC) is the second leading cause of cancer death among Filipino women. Human papillomavirus (HPV) vaccination protects against CC. Two vaccines (AS04-HPV-16/18 and 4vHPV) are approved in the Philippines; they were originally developed for a 3-dose (3D) administration and have recently been approved in a 2-dose schedule (2D). This study aims to evaluate the cost-effectiveness of HPV vaccination of 13-year-old Filipino girls, in addition to current screening, in the new 2D schedule. An existing static lifetime, one-year cycle Markov cohort model was adapted to the Philippine settings to simulate the natural history of low-risk and oncogenic HPV infection, the effects of screening and vaccination of a 13-year-old girls cohort vaccinated with either the 2D-AS04-HPV-16/18 or 2D-4vHPV assuming a 100% vaccination coverage. Incremental cost, quality-adjusted life year (QALY) and cost-effectiveness were derived from these estimates. Input data were obtained from published sources and Delphi panel, using country-specific data where possible. Sensitivity analyses were performed to assess the robustness of the model. The model estimated that 2D-AS04-HPV-16/18 prevented 986 additional CC cases and 399 CC deaths (undiscounted), as well as 555 increased QALY (discounted), and save 228.1 million Philippine pesos (PHP) compared with the 2D-4vHPV. In conclusion, AS04-HPV-16/18 is shown to be dominant over 4vHPV in the Philippines, with greater estimated health benefits and lower costs.

Preventive vaccination against cervical cancer: Korean Society of Gynecologic Oncology Guideline

After human papillomavirus (HPV) vaccine guidelines published by Korean Society of Gynecologic Oncology (KSGO) in 2011, new studies have been published, leading to additional data regarding efficacy, safety, number of vaccination rounds, and ideal age of vaccine administration. We searched and reviewed the literatures focused on the efficacy of 2-dose schedule vaccination, the efficacy of 3-dose schedule vaccination in middle-aged women, the ideal age of 3-dose schedule vaccination, the safety of HPV preventive vaccine, and the ability of cross-protection of each HPV preventive vaccine. The KSGO has revised the previous guideline based on the results of the above studies.

HPV vaccine completion and dose adherence among commercially insured females aged 9 through 26 years in the US

BACKGROUND

Although HPV vaccination has been recommended for use in girls and young women since 2007, HPV vaccine uptake is low in the US.

METHODS

We conducted a retrospective cohort study using the 2008-2011 MarketScan data to examine HPV vaccine completion and dose adherence among commercially insured females aged 9-26 years. We performed multivariable logistic regression models to examine factors related to HPV vaccine completion and HPV vaccine dose adherence.

RESULTS

Among 378,484 females aged 9-26 years who initiated HPV vaccination, only 29.4% completed HPV vaccination. Compared with females receiving vaccines from primary care providers, those receiving vaccines from OB/GYN providers were more likely to complete the vaccine series. Age at HPV vaccine initiation, health insurance plan, seasonal pattern, and flu vaccination were also significantly associated with vaccine completion. Among 111,286 females who completed HPV vaccination, 62.4% received all doses within 30 days of the recommended schedules. Similar factors relating to HPV vaccine completion were consistently associated with HPV vaccine dose adherence. However, younger age (<22 years) and receipt of flu vaccine were negatively related to HPV vaccine dose adherence.

CONCLUSIONS

Intervention programs to improve HPV vaccine reminding system and reduce logistic barriers for both physicians and patients are warranted.

Human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine for the prevention of cervical cancer and HPV-related diseases

Vaccines are available against human papillomavirus (HPV), the causal agent of cervical and other cancers. Efficacy data from the HPV-16/18 AS04-adjuvanted vaccine clinical trial program were reviewed. Six randomized, controlled phase II/III trials evaluating cervical endpoints enrolled women from diverse populations and geographical locations. The program analyzed extensively the cohorts most relevant from a public health perspective: the total vaccinated cohort (TVC), approximating a general population including those with existing or previous HPV infection, and TVC-naïve, approximating a population of young women before sexual debut. Results show that the vaccine reduces HPV-16/18 infection and associated cervical endpoints in women regardless of age, location, or sexual experience. It provides cross-protection against some non-vaccine oncogenic HPV types and types causing genital warts, and may be effective against vulvar, oral, and anal HPV infection. Early epidemiology data following its introduction suggest a decline in the prevalence of vaccine and some non-vaccine HPV types.

Ten years of anti-HPV vaccinations: what do we know?

Human papillomavirus (HPV) is one of the most important carcinogens in humans. Vaccines against HPV are now considered the first anti-cancer vaccinations. Since 2007, in many developed countries, there have been recommendations present for preventive vaccines against HPV. At present, the degree of implementation of these recommendations depends on a number of country-specific factors such as the health care system organization or the ways of funding. HPV vaccines are primarily to prevent the development of cervical cancer and other genital cancers. Therefore, only their long-term effectiveness can be measured, when a correspondingly large cohort of vaccinated teenagers reaches the age of the greatest incidence of these cancers. However, great care should be taken in assessing the results of vaccinations due to the possibility of misinterpretation and possible erroneous data. Undoubtedly, teenagers are the target population of HPV vaccines. However, vaccinating young sexually active women is also justified from an individual point of view. A 9-valent vaccine has been registered in the USA and in Europe - including Poland - as one of the three preventive vaccines. It is recommended to vaccinate women between 13 and 26 and men between 13 and 21, previously unvaccinated. It is also recommended to vaccinate men aged 26 years or less who have sexual relations with other men and people with reduced immunity, including HIV-positive people who have not been vaccinated previously.

Extending the Human Papillomavirus Vaccination Programme to Include Males in High-Income Countries: A Systematic Review of the Cost-Effectiveness Studies

BACKGROUND AND OBJECTIVES

Giving the human papillomavirus (HPV) vaccination to females has been shown to be cost-effective in most countries. The epidemiological evidence and economic burden of HPV-related diseases have gradually been shown to be gender neutral. Randomized clinical trials report high efficacy, immunogenicity and safety of the HPV vaccine in males aged 16-26 years. Some pioneering countries extended their HPV vaccination programme to include males, regardless of the cost-effectiveness analysis results. Nevertheless, decision makers need evidence provided by modelling and economic studies to justify the funding of mass vaccination. This systematic review aims to assess the cost-effectiveness of extending the HPV vaccination programme to include males living in high-income countries.

METHODS

A systematic review of the cost-effectiveness analyses of HPV vaccination in males was performed. Data were extracted and analysed using a checklist adapted from the Consolidated Health Economic Evaluation Reporting Standards Statement.

RESULTS

Seventeen studies and 12 underlying mathematical models were identified. Model filiation showed evolution in time from aggregate models (static and dynamic) to individual-based models. When considering the health outcomes HPV vaccines are licensed for, regardless of modelling approaches and assumptions, extending vaccinations to males is rarely found to be cost-effective in heterosexual populations. Cost-effectiveness ratios become more attractive when all HPV-related diseases are considered and when vaccine coverage in females is below 40%.

CONCLUSION

Targeted vaccination of men who have sex with men (MSM) seems to be the best cost-effectiveness option. The feasibility of this strategy is still an open question, since early identification of this specific population remains difficult.

Eurogin Roadmap 2015: How has HPV knowledge changed our practice: Vaccines

This review is one of two complementary reviews that have been prepared in the framework of the Eurogin Roadmap 2015 to evaluate how knowledge about HPV is changing practices in HPV infection and disease control through vaccination and screening. In this review of HPV vaccine knowledge, we present the most significant findings of the past year which have contributed to our knowledge of the two HPV prophylactic vaccines currently in widespread use and about the recently licensed nonavalent HPV vaccine. Whereas anal cancer is dealt with in the companion mini-review on screening, we also review here the rapidly evolving evidence regarding HPV-associated head and neck cancer and priority research areas.

Current global status & impact of human papillomavirus vaccination: Implications for India

This review addresses the effectiveness and safety of human papillomavirus (HPV) vaccines, the current status of its introduction in the National Immunization Programmes (NIPs) and its relevance to India, which contributes a fifth of the global burden of cervical cancer. The vast literature on efficacy, acceptability and safety of HPV vaccination and its impact after population level introduction was reviewed and discussed. The efficacy of HPV vaccines in preventing high-grade precancerous lesions caused by vaccine-targeted HPV infections was 90 per cent or higher in HPV naοve women in randomized clinical trials. Two doses at 6 or 12 months apart are recommended for 9-14 yr old girls and three doses over six months to one year period for those aged above 15 yr. More than 80 countries or territories have introduced HPV vaccination in their NIPs, of which 33 are low- and middle-income countries (LMICs); in addition, 25 LMICs have introduced pilot programmes before a phased national expansion. Significant reductions in the frequency of HPV 16 and 18 infections, genital warts and cervical premalignant lesions in vaccinated cohorts and herd immunity in general populations have been reported from countries that introduced vaccination in NIPs as early as 2007. More than 280 million doses of HPV vaccines have been administered worldwide with the excellent safety profile with no serious adverse events linked to it. The high burden of cervical cancer and the high efficacy and safety of HPV vaccination justify its introduction in the Indian NIP at the earliest possibility to substantially reduce the cervical cancer burden in future.

Gender-neutrality, herd effect and resilient immune response for sustainable impact of HPV vaccination

PURPOSE OF REVIEW

This review summarize the impact of various strategies of human papillomavirus (HPV) vaccination, such as vaccinating only girls or both girls and boys.

RECENT FINDINGS

Slow and inefficient implementation of HPV vaccination programmes has delayed the impact of the first human cancer vaccine. Vaccinating only girls, with a rather low coverage, has led to a limited herd effect and, thus, not full use of the HPV vaccine potential.

SUMMARY

Gender-neutral vaccination based on comparative effectiveness research will hopefully soon tackle the whole spectrum of HPV cancers in both sexes. The remaining challenges are how to ensure resilience of HPV vaccine-induced immunity and herd effect to guarantee population-level impact of HPV vaccination, and how to guard against HPV type replacement.

Cervical cancer prevention and treatment research in Africa: a systematic review from a public health perspective

BACKGROUND

Women living in Africa experience the highest burden of cervical cancer. Research and investment to improve vaccination, screening, and treatment efforts are critically needed. We systematically reviewed and characterized recent research within a broader public health framework to organize and assess the range of cervical cancer research in Africa.

METHODS

We searched online databases and the Internet for published articles and cervical cancer reports in African countries. Inclusion criteria included publication between 2004 and 2014, cervical cancer-related content pertinent to one of the four public health categories (primary, secondary, tertiary prevention or quality of life), and conducted in or specifically relevant to countries or regions within the African continent. The study design, geographic region/country, focus of research, and key findings were documented for each eligible article and summarized to illustrate the weight and research coverage in each area. Publications with more than one focus (e.g. secondary and tertiary prevention) were categorized by the primary emphasis of the paper. Research specific to HIV-infected women or focused on feasibility issues was delineated within each of the four public health categories.

RESULTS

A total of 380 research articles/reports were included. The majority (54.6 %) of cervical cancer research in Africa focused on secondary prevention (i.e., screening). The number of publication focusing on primary prevention (23.4 %), particularly HPV vaccination, increased significantly in the past decade. Research regarding the treatment of precancerous lesions and invasive cervical cancer is emerging (17.6 %), but infrastructure and feasibility challenges in many countries have impeded efforts to provide and evaluate treatment. Studies assessing aspects of quality of life among women living with cervical cancer are severely limited (4.1 %). Across all categories, 11.3 % of publications focused on cervical cancer among HIV-infected women, while 17.1 % focused on aspects of feasibility for cervical cancer control efforts.

CONCLUSIONS

Cervical cancer research in African countries has increased steadily over the past decade, but more is needed. Tertiary prevention (i.e. treatment of disease with effective medicine) and quality of life of cervical cancer survivors are two severely under-researched areas. Similarly, there are several countries in Africa with little to no research ever conducted on cervical cancer.

The impact and cost-effectiveness of nonavalent HPV vaccination in the United States: Estimates from a simplified transmission model

INTRODUCTION

The objective of this study was to assess the incremental costs and benefits of the 9-valent HPV vaccine (9vHPV) compared with the quadrivalent HPV vaccine (4vHPV). Like 4vHPV, 9vHPV protects against HPV types 6, 11, 16, and 18. 9vHPV also protects against 5 additional HPV types 31, 33, 45, 52, and 58.

METHODS

We adapted a previously published model of the impact and cost-effectiveness of 4vHPV to include the 5 additional HPV types in 9vHPV. The vaccine strategies we examined were (1) 4vHPV for males and females; (2) 9vHPV for females and 4vHPV for males; and (3) 9vHPV for males and females. In the base case, 9vHPV cost $13 more per dose than 4vHPV, based on available vaccine price information.

RESULTS

Providing 9vHPV to females compared with 4vHPV for females (assuming 4vHPV for males in both scenarios) was cost-saving regardless of whether or not cross-protection for 4vHPV was assumed. The cost per quality-adjusted life year (QALY) gained by 9vHPV for both sexes (compared with 4vHPV for both sexes) was < $0 (cost-saving) when assuming no cross-protection for 4vHPV and $8,600 when assuming cross-protection for 4vHPV.

CONCLUSIONS

Compared with a vaccination program of 4vHPV for both sexes, a vaccination program of 9vHPV for both sexes can improve health outcomes and can be cost-saving.

An exploration of individual- and population-level impact of the 2-dose HPV vaccination schedule in pre-adolescent girls

Since 2014, several countries have implemented a 2-dose schedule for Human papillomavirus (HPV) vaccination. Licensure of the 2-dose schedule was based on non-inferiority results from immunobridging studies, comparing the antibody levels of the 2-dose schedule in young girls to those of the 3-dose schedule in young adults. Since licensure, additional data on antibody levels and other aspects of the immune response and clinical effectiveness have become available. This review will discuss the current outcomes on immunogenicity and effectiveness together with an exploration on the population impact of 2-dose schedules from a cost-effectiveness perspective. The 2-dose schedule has important benefits, such as easier logistics, reduced expenditure, potentially higher acceptance and fewer side effects. Policymakers and registration authorities should consider whether these benefits outweigh the likely differences on individual- and population-level impact between the 2- and 3-dose schedules.

Comparative immunogenicity and safety of human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine and HPV-6/11/16/18 vaccine administered according to 2- and 3-dose schedules in girls aged 9-14 years: Results to month 12 from a randomized trial

This observer-blind study (clinicaltrials.gov NCT01462357) compared the immunogenicity and safety of 2 doses of the HPV-16/18 AS04-adjuvanted vaccine (HPV-16/18(2D)) vs. 2 or 3 doses of the HPV-6/11/16/18 vaccine (HPV-6/11/16/18(2D) and HPV-6/11/16/18(3D)) in healthy girls aged 9–14 y. Girls were randomized (1:1:1) to receive HPV-16/18(2D) at months (M) 0,6 (N = 359), HPV-6/11/16/18(2D) at M0,6 (N = 358) or HPV-6/11/16/18(3D) at M0,2,6 (N = 358). The primary objective was non-inferiority/superiority of HPV-16/18 antibodies by ELISA for HPV-16/18(2D) vs. HPV-6/11/16/18(2D) at M7 in the according-to-protocol immunogenicity cohort (ATP-I) and total vaccinated cohort, respectively. Secondary objectives included non-inferiority/superiority of HPV-16/18(2D) vs. HPV-6/11/16/18(3D) at M7, non-inferiority/superiority at M12, HPV-16/18 neutralizing antibodies, frequencies of T-cells/B-cells, reactogenicity and safety. Antibody responses at M7 for HPV-16/18(2D) were superior to those for HPV-6/11/16/18(2D) and HPV-6/11/16/18(3D) (lower limit of 95% confidence interval for geometric mean titer ratio (GMR) was >1): HPV-16/18(2D)/HPV-6/11/16/18(2D) GMRs were 1.69 [1.49–1.91] for anti-HPV-16 and 4.52 [3.97–5.13] for anti-HPV-18; HPV-16/18(2D)/HPV-6/11/16/18(3D) GMRs were 1.72 [1.54–1.93] for anti-HPV-16 and 3.22 [2.82–3.68] for anti-HPV-18; p = 0.0001 for all comparisons. Non-inferiority/superiority was also demonstrated at M12. Among initially seronegative girls in the ATP-I, neutralizing antibody titers were at least 1.8-fold higher for HPV-16/18(2D) vs. HPV-6/11/16/18(2D) and HPV-6/11/16/18(3D) at M7 and M12. Frequencies of HPV-16/18-specific T-cells and B-cells were in similar ranges between groups. Reactogenicity and safety were in line with the known profile of each vaccine. In conclusion, superior HPV-16/18 antibody responses were elicited by 2 doses of the HPV-16/18 AS04-adjuvanted vaccine compared with 2 or 3 doses of the HPV-6/11/16/18 vaccine in girls (9–14 years).

Current status of human papillomavirus vaccination

PURPOSE OF REVIEW

In this article, we review the impact of the quadrivalent and bivalent prophylactic human papillomavirus (HPV) vaccines on HPV infection and disease, review alternative vaccine dosing schedules, the vaccination of men and the nine-valent HPV vaccine.

RECENT FINDINGS

HPV vaccines have had dramatic impacts on the prevalence of targeted HPV types (6,11,16 and 18), genital warts and precancerous cervical lesions. Population coverage would be facilitated by adopting two-dose schedules, with recent findings that two-dose schedules in young adolescents are as immunogenic as three doses in young adults. Extension of vaccination to men, particularly for men who have sex with men, could further reduce population prevalence of HPV and provide direct protection to men against genital warts and anal, penile and oropharyngeal cancers. The nine-valent HPV vaccine has demonstrated equivalent protection against the four types in the quadrivalent vaccine and high efficacy against the next five commonest causes of cervical cancer (HPV types 31,33,45,52 and 58). If cost-effective, it may extend the spectrum of protection against cervical cancer available through vaccination.

SUMMARY

HPV vaccination is an effective strategy for reducing the burden of HPV-related disease. New schedules, target populations and vaccines promise to expand this potential further.

HPV Serology Testing Confirms High HPV Immunisation Coverage in England

Background

Reported human papillomavirus (HPV) vaccination coverage in England is high, particularly in girls offered routine immunisation at age 12 years. Serological surveillance can be used to validate reported coverage and explore variations within it and changes in serological markers over time.

Methods

Residual serum specimens collected from females aged 15–19 years in 2010–2011 were tested for anti-HPV16 and HPV18 IgG by ELISA. Based on these results, females were classified as follows: seronegative, probable natural infection, probable vaccine-induced seropositivity, or possible natural infection/possible vaccine-induced seropositivity. The proportion of females with vaccine-induced seropositivity was compared to the reported vaccination coverage.

Results

Of 2146 specimens tested, 1380 (64%) were seropositive for both types HPV16 and HPV18 and 159 (7.4%) positive for only one HPV type. The IgG concentrations were far higher for those positive for both HPV types than those positive for only one HPV type. 1320 (62%) females were considered to have probable vaccine-induced seropositivity. Among vaccine-induced seropositives, antibody concentrations declined with increasing age at vaccination and increasing time since vaccination.

Conclusions

The proportion of females with vaccine-induced seropositivity was closest to the reported 3-dose coverage in those offered the vaccination at younger ages, with a greater discrepancy in the older females. This suggests either some under-reporting of immunisations of older females and/or that partial vaccination (i.e. one- or two-doses) has provided high antibody responses in 13–17 year olds.

Randomized Open Trial Comparing 2-Dose Regimens of the Human Papillomavirus 16/18 AS04-Adjuvanted Vaccine in Girls Aged 9-14 Years Versus a 3-Dose Regimen in Women Aged 15-25 Years

Background. This randomized, open trial compared regimens including 2 doses (2D) of human papillomavirus (HPV) 16/18 AS04-adjuvanted vaccine in girls aged 9–14 years with one including 3 doses (3D) in women aged 15–25 years.

Methods. Girls aged 9–14 years were randomized to receive 2D at months 0 and 6 (M0,6; (n = 550) or months 0 and 12 (M0,12; n = 415), and women aged 15–25 years received 3D at months 0, 1, and 6 (n = 482). End points included noninferiority of HPV-16/18 antibodies by enzyme-linked immunosorbent assay for 2D (M0,6) versus 3D (primary), 2D (M0,12) versus 3D, and 2D (M0,6) versus 2D (M0,12); neutralizing antibodies; cell-mediated immunity; reactogenicity; and safety. Limits of noninferiority were predefined as <5% difference in seroconversion rate and <2-fold difference in geometric mean antibody titer ratio.

Results. One month after the last dose, both 2D regimens in girls aged 9–14 years were noninferior to 3D in women aged 15–25 years and 2D (M0,12) was noninferior to 2D (M0,6). Geometric mean antibody titer ratios (3D/2D) for HPV-16 and HPV-18 were 1.09 (95% confidence interval, .97–1.22) and 0.85 (.76–.95) for 2D (M0,6) versus 3D and 0.89 (.79–1.01) and 0.75 (.67–.85) for 2D (M0,12) versus 3D. The safety profile was clinically acceptable in all groups.

Conclusions. The 2D regimens for the HPV-16/18 AS04-adjuvanted vaccine in girls aged 9–14 years (M0,6 or M0,12) elicited HPV-16/18 immune responses that were noninferior to 3D in women aged 15–25 years.

Clinical Trials Registration. NCT01381575.

Immunogenicity and HPV infection after one, two, and three doses of quadrivalent HPV vaccine in girls in India: a multicentre prospective cohort study

BACKGROUND

An increase in worldwide HPV vaccination could be facilitated if fewer than three doses of vaccine are as effective as three doses. We originally aimed to compare the immunogenicity and frequency of persistent infection and cervical precancerous lesions caused by vaccine-targeted HPV after vaccination with two doses of quadrivalent vaccine on days 1 and 180 or later, with three doses on days 1, 60, and 180 or later, in a cluster-randomised trial. Suspension of the recruitment and vaccination due to events unrelated to our study meant that some enrolled girls could not be vaccinated and some vaccinated girls received fewer than the planned number of vaccinations by default. As a result, we re-analysed our data as an observational cohort study.

METHODS

Our study was designed to be done in nine locations (188 clusters) in India. Participants were unmarried girls aged 10-18 years vaccinated in four cohorts: girls who received three doses of vaccine on days 1, 60, and 180 or later, two doses on days 1 and 180 or later, two doses on days 1 and 60 by default, and one dose by default. The primary outcomes were immunogenicity in terms of L1 genotype-specific binding antibody titres, neutralising antibody titres, and antibody avidity after vaccination for the vaccine-targeted HPV types 16, 18, 6, and 11 and incident and persistent infections with these HPVs. Analysis was per actual number of vaccine doses received. This study is registered with ISRCTN, number ISRCTN98283094; and with ClinicalTrials.gov, number NCT00923702.

FINDINGS

Vaccination of eligible girls was initiated on Sept 1, 2009, and continued until April 8, 2010. Of 21 258 eligible girls identified at 188 clusters, 17 729 girls were recruited from 178 clusters before suspension. 4348 (25%) girls received three doses, 4979 (28%) received two doses on days 1 and 180 or later, 3452 (19%) received two doses at days 1 and 60, and 4950 (28%) received one dose. Immune response in the two-dose HPV vaccine group was non-inferior to the three-dose group (median fluorescence intensity ratio for HPV 16 1·12 [95% CI 1·02-1·23] and for HPV 18 1·04 [0·92-1·19]) at 7 months, but was inferior in the two-dose default (0·33 [0·29-0·38] for HPV 16 and 0·51 [0·43-0·59] for HPV 18) and one-dose default (0·09 [0·08-0·11] for HPV 16 and 0·12 [0·10-0·14] for HPV 18) groups at 18 months. The geometric mean avidity indices after fewer than three doses by design or default were non-inferior to those after three doses of vaccine. Fewer than three doses by design and default induced detectable concentrations of neutralising antibodies to all four vaccine-targeted HPV types, but at much lower concentration after one dose. Cervical samples from 2649 participants were tested and the frequency of incident HPV 16, 18, 6, and 11 infections was similar irrespective of the number of vaccine doses received. The testing of at least two samples from 838 participants showed that there was no persistent HPV 16 or 18 infections in any study group at a median follow-up of 4·7 years (IQR 4·2-5·1).

INTERPRETATION

Despite the limitations imposed by the suspension of the HPV vaccination, our findings lend support to the WHO recommendation of two doses, at least 6 months apart, for routine vaccination of young girls. The short-term protection afforded by one dose of HPV vaccine against persistent infection with HPV 16, 18, 6, and 11 is similar to that afforded by two or three doses of vaccine and merits further assessment.

FUNDING

Bill & Melinda Gates Foundation.