Sustained Cross-reactive Antibody Responses After Human Papillomavirus Vaccinations: Up to 12 Years Follow-up in the Finnish Maternity Cohort

Head-to-head comparison of two human papillomavirus vaccines for efficacy against cervical intraepithelial neoplasia grade 3 and adenocarcinoma in situ-population-based follow-up of two cluster-randomized trials

Introduction

We report head-to-head comparison of the bivalent and quadrivalent HPV vaccine efficacies against immediate precursors of cervical cancer from 15 years' country-wide cancer registry follow-up of phase III trial cohorts and an age-aligned cohort of unvaccinated women.

Methods

These individually and/or clusterrandomized cohorts of HPV6/11/16/18- and HPV16/18-vaccinated and unvaccinated women were enrolled, respectively, in 2002, 2004, and 2003/2005. The trial cohorts comprised initially 16- to 17-year-old HPV6/11/16/18-vaccinated FUTURE II (NCT00092534) participants (866) and HPV16/18-vaccinated PATRICIA (NCT00122681) and 012 trial (NCT00169494) participants (2,465), and 16,526 initially 16- to 19-year-old unvaccinated controls. After active 4-year clinical follow-up, passive, country-wide Finnish Cancer Registry (FCR) follow-up for cervical intraepithelial neoplasia grade 3 (CIN3) and adenocarcinoma in situ (AIS) was based on consented use of unique personal identifiers and started 6 months after the end of the FUTURE II and PATRICIA trials in 2007 and 2009, and ended at the end of 2019. The follow-up with altogether 229,020 follow-up years was age-aligned to ensure that similarly aged cohorts were passively followed up for 15 years post=vaccination for the intention-to-treat analyses of vaccine efficacy.

Results

Overall, we identified 5 and 16 CIN3 (no AIS) cases in the HPV6/11/16/18 and HPV16/18 cohorts, respectively, during the FCR-based follow-up. In the unvaccinated cohort, we identified 281 CIN3 cases, 20 AIS cases, and 13 cases with invasive cervical cancer. Vaccine efficacies against CIN3+ were 68.4% and 64.5% for the quadrivalent and the bivalent vaccines, respectively, with overlapping confidence intervals.

Discussion

Long-term follow-up of randomized, initially adolescent HPV-vaccinated and unvaccinated cohorts shows, in this head-to-head setting, that the bivalent and quadrivalent HPV vaccines are equally effective against immediate precursors of cervical cancer.

Lack of detectable HPV18 antibodies in 14% of quadrivalent vaccinees in a longitudinal cohort study

Although HPV vaccines are highly efficacious, a notable proportion of quadrivalent vaccinees are HPV18 seronegative post-vaccination. We have investigated this findings' validity by comparing vaccine-induced antibody responses using two different immunoassays. 6558 16-17-year-old females participated in the FUTURE II (NCT00092534) and PATRICIA (NCT00122681) trials in 2002-2004. Both the quadrivalent and bivalent vaccine recipients (QVR and BVR) received three doses. Twelve-year follow-up for 648 vaccinees was conducted by the Finnish Maternity Cohort. The presence of neutralising and binding HPV antibodies was analysed via HPV pseudovirion-based neutralisation and pseudovirion-binding assays. Four percent and 14.3% of the QVRs were seronegative for neutralising and binding antibodies to HPV16 and HPV18, respectively. No BVRs were HPV16/18 seronegative post-vaccination. The antibody titres were strongly correlated between the assays, Pearson's correlation coefficient, r[HPV16] = 0.92 and 0.85, and r[HPV18] = 0.91 and 0.86 among the QVRs and BVRs respectively. Fourteen percent of QVRs lacked detectable HPV18 antibodies in long-term follow-up.

The Non-inferiority of Human Papillomavirus Vaccine Immunogenicity Among Women Over 26 Years: A Systematic Review

OBJECTIVE

Demonstrate the immunogenicity of the human papillomavirus (HPV) vaccine for the older age group (above 26 years) to prevent HPV infection with high-risk types and argue for extending vaccination recommendations for the older age group.

METHODS

Two authors searched PubMed, Embase, and the Cochrane Library from inception to December 2023 to collect information on clinical trials of HPV vaccine immunogenicity. The database search strategy used a combination of subject terms and free terms. Two authors first identified studies by reading the title, abstract, and full texts and, subsequently, based on the inclusion criteria. Studies eligible to be included are the clinical trials using one of the following types of HPV vaccines: 2vHPV, 4vHPV, and 9vHPV, and measuring the immunogenicity by the geometric mean concentration or titer (GMC/T) and seroconversion rate (SCR) among healthy women aged 9 to 55 years who had never received a prophylactic HPV vaccine, known serostatus for HPV, non-immunocompetence, or non-pregnant.

RESULTS

This review included nine articles, seven RCTs, and two open-labeled studies.

CONCLUSION

In summary, we have demonstrated that the immunogenicity of the HPV vaccines is non-inferior in the older age group. Even though the GMT declines with age, the SCR is similar in all age groups regardless of the serostatus. The immunogenicity of the bivalent vaccine is superior to that of the quadrivalent vaccine for the older age group. Additionally, the vaccine is more efficient in women under the age of 26, but older women will benefit from it.

Scientific approaches toward improving cervical cancer elimination strategies

At the 2023 EUROGIN workshop scientific basis for strategies to accelerate the elimination of cervical cancer and its causative agent, human papillomavirus (HPV) were reviewed. Although some countries have reached key performance indicators toward elimination (>90% of girls HPV vaccinated and >70% of women HPV screened), most are yet to reach these targets, implying a need for improved strategies. Gender-neutral vaccination, even with moderate vaccination coverage was highlighted as a strategy to achieve elimination more rapidly. It is more resilient against major disturbances in vaccination delivery, such as what happened during the coronavirus pandemic. Further, an analysis of ethical/legal issues indicated that female-restricted vaccination is problematic. Extended catch-up of vaccination with concomitant screening, and outreach to vulnerable groups were highlighted. Although birth cohorts with high coverage of HPV vaccination at school are protected against HPV, and HPVs have a very low reproductive rate in women above age 35, adult women below age 30 have inadequate direct protection. In addition to herd protection from gender-neutral vaccination, this group can be protected by offering concomitant catch-up HPV vaccination and HPV screening. Furthermore, hepatitis B vaccination experiences indicate that elimination cannot be achieved without prioritizing vulnerable/migrant populations. The long-lasting durability of vaccination-induced antibody responses suggests prolonged protection with HPV vaccines when adequately administrated. Finally, cost-effectiveness modelling suggests that high-coverage HPV vaccination in multiple population segments will be resource-saving due to reduced need for screening. In summary, the workshop found that strategically optimal deployment of vaccination will accelerate elimination of HPV and cervical cancer.

Immune response following a two-dose schedule of bivalent HPV vaccination among girls and boys

Background

This longitudinal cohort study describes the kinetics in antibody levels after two doses of the bivalent human papillomavirus (HPV) vaccine in girls (birth cohort 2001) vaccinated in the routine Dutch vaccination program at 12 years of age, up to 7.5 years post-vaccination. Also, the antibody response one month post-vaccination of the first cohort of boys (birth cohort 2012, vaccinated at 10 years of age) eligible for HPV vaccination in the Netherlands is presented.

Method

Blood samples and questionnaire data were collected of girls and boys. HPV type-specific antibody concentrations (LU/mL) against HPV16/18/31/33/45/52/58 were assessed using a validated virus-like particle (VLP) multiplex immunoassay. For girls, antibody decays over time were modelled using the modified power-law decay model and the exponential decay model.

Results

The Geometric Mean Concentrations (GMCs) remained higher for HPV16/18 than for HPV types 31, 33, 45, 52, and 58 among girls up to 7.5 years post-vaccination. The antibody levels of HPV16 and HPV18 reached plateau values of 482 and 159 LU/mL, respectively. Mathematical modelling showed that the half-life values of HPV16/18 were 2.4- to 4.5-fold higher compared with the half-life values of the other HPV types. Among boys (aged 10 years), the GMC for HPV16 was significantly higher than among girls one month post-vaccination (aged 12 years).

Conclusion

The GMCs of all HPV types declined over time, although the GMCs of HPV16/18 remained relatively high up to 7.5 years post-vaccination. The GMCs for HPV16/18 among boys were at least equally high as the GMCs among girls at one month post-vaccination. Further follow-up of the cohort of boys is needed to gain knowledge on long-term immune responses of young boys following bivalent HPV vaccination.

Ecological diversity profiles of non-vaccine-targeted HPVs after gender-based community vaccination efforts

The long-term effect of population-level human papillomavirus (HPV) vaccination on the viral ecology of the untargeted HPVs is poorly understood. We performed an 8-year follow-up of 33 communities randomized to gender-neutral HPV16/18 vaccination, girls-only HPV16/18 vaccination, and control communities without HPV vaccination. The 1992/93 and 1994 birth cohorts were invited in school years 2007/8 and 2008/9. Follow-up cervico-vaginal sampling at 18 and 22 years of age, 4 and 8 years post-vaccination, respectively, were attended by 11,396 and 5,602 participants. HPV types 6/11/16/18/31/33/35/39/45/51/52/56/58/59/66/68 were genotyped and used for the community-level ecological diversity estimations. Gender-neutral vaccination communities with a stronger herd immunity than girls-only vaccination communities show a significantly increased HPV α-diversity (p = 1.1 × 10-8) from 4 to 8 years post-vaccination, despite the clearance of the vaccine-targeted HPVs in these communities. This likely sign of niche occupation by the non-vaccine-targeted HPVs will potentially affect the future cervical cancer screening programs but should not interfere with the WHO mission to eliminate cervical cancer.

Differences in HPV-specific antibody Fc-effector functions following Gardasil® and Cervarix® vaccination

Gardasil® (Merck) and Cervarix® (GlaxoSmithKline) both provide protection against infection with Human Papillomavirus 16 (HPV16) and Human Papillomavirus 18 (HPV18), that account for around 70% of cervical cancers. Both vaccines have been shown to induce high levels of neutralizing antibodies and are known to protect against progression beyond cervical intraepithelial neoplasia grade 2 (CIN2+), although Cervarix® has been linked to enhanced protection from progression. However, beyond the transmission-blocking activity of neutralizing antibodies against HPV, no clear correlate of protection has been defined that may explain persistent control and clearance elicited by HPV vaccines. Beyond blocking, antibodies contribute to antiviral activity via the recruitment of the cytotoxic and opsonophagocytic power of the immune system. Thus, here, we used systems serology to comprehensively profile Gardasil®- and Cervarix®- induced antibody subclass, isotype, Fc-receptor binding, and Fc-effector functions against the HPV16 and HPV18 major capsid protein (L1). Overall, both vaccines induced robust functional humoral immune responses against both HPV16 and HPV18. However, Cervarix® elicited higher IgG3 and antibody-dependent complement activating responses, and an overall more coordinated response between HPV16 and 18 compared to Gardasil®, potentially related to the distinct adjuvants delivered with the vaccines. Thus, these data point to robust Fc-effector functions induced by both Gardasil® and Cervarix®, albeit with enhanced coordination observed with Cervarix®, potentially underlying immunological correlates of post-infection control of HPV.

A novel C-terminal modification method enhanced the yield of human papillomavirus L1 or chimeric L1-L2 virus-like particles in the baculovirus system

Human papillomavirus (HPV) major capsid protein L1 virus-like particles (VLPs) produced in the baculovirus system showed excellent safety and immunogenicity, but the relatively high production cost stands as a substantial barrier to extensive commercialization, especially in producing multivalent vaccines. Here, a novel method, C-terminal basic amino acid (aa) substitution, was developed for increasing VLP and chimeric VLP (cVLP) production in this system. A series of mutants of five HPV types, including three L1 VLPs (6L1, 11L1, and 52L1) and two L1-L2 cVLPs (16L1-33L2, 58L1-16L2), were constructed. We found that most mutants exhibited higher protein expression in Sf9 cells, among which the yields of the superior mutants, 6L1CS4, 11L1CS3, 52L1m4∆N13CS1, 16L1-33L2 CS1, and 58L1-16L2 CS3, were up to 40, 35, 20, 35, and 60 mg/L, which respectively increased by 4.2-, 7.3-, 5-, 2.5-, and 3.4-fold, and they also showed robust immunogenicity and great stabilities. Additionally, we found that the increased level of steady-state mRNA may play a crucial role in promoting L1 protein expression. Our results demonstrated that this novel method was cost-effective and can be used to reduce the production costs of L1 VLPs and L1-L2 cVLPs to develop broadly protective and affordable multivalent HPV vaccines.

Head-to-Head Comparison of Bi- and Nonavalent Human Papillomavirus Vaccine-Induced Antibody Responses

For head-to-head comparison of human papillomavirus (HPV) antibody levels induced by different vaccines, 25-year-old vaccine-naive women were given either the bivalent (n = 188) or the nonavalent HPV vaccine (n = 184). Six months after vaccination antibodies against pseudovirions from 17 different HPV types (HPV6/11/16/18/31/33/35/39/45/51/52/56/58/59/66/68/73) were measured. Antibodies against HPV16/18 were higher after bivalent HPV vaccination (mean international units [IU] 1140.1 and 170.5 for HPV16 and 18, respectively) than after nonavalent vaccination (265.1 and 22.3 IUs, respectively). The bivalent vaccine commonly induced antibodies against the nonvaccine HPV types 31/33/35/45 or 58. The nonavalent vaccine induced higher antibodies against HPV6/11/31/33/45/52/58 and 35.

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.

Binding antibody levels to vaccine (HPV6/11/16/18) and non-vaccine (HPV31/33/45/52/58) HPV antigens up to 7 years following immunization with either Cervarix® or Gardasil® vaccine

Human Papillomavirus (HPV) bivalent (Cervarix®) and quadrivalent (Gardasil®) vaccines demonstrate robust efficacy against vaccine types and cross-protection against related non-vaccine types. Here we evaluate the breadth, magnitude and durability of the vaccine-induced antibody response against vaccine (HPV6/11/16/18) and non-vaccine (HPV31/33/45/52/58) type antigens up to 7 years following vaccination of 12-15 year old girls in a three dose schedule and contrast these data with the levels of antibody typically seen in natural infection. Vaccine-type antibody levels waned over the 7-year follow up period but remained at least an order of magnitude above the typical antibody levels elicited by natural infection. Seropositivity to non-vaccine types remained high 7 years after initial vaccination, but antibody levels approached those typically generated following natural infection. Empirical data on the breadth, magnitude, specificity and durability of the immune response elicited by the HPV vaccines contribute to improving the evidence base supporting this important public health intervention.

Combined truncations at both N- and C-terminus of human papillomavirus type 58 L1 enhanced the yield of virus-like particles produced in a baculovirus system

Human papillomavirus (HPV) major capsid protein L1 virus-like particles (VLPs) produced in baculovirus system are highly immunogenic, but the relatively high production cost limits its application in the development of broad-spectrum vaccines. Here we report a novel method for enhancing VLP production in this system. We incorporated respectively 4, 8 or 13 residues truncation mutations in the N-terminus of L1ΔC, a C-terminal 25-residue-deleted L1 of HPV58, to construct three mutants. After expression in Sf9 cells, L1ΔN4C exhibited 2.3-fold higher protein production, 2.0-fold mRNA expression and lower rate of mRNA decay, compared to L1ΔC. More importantly, L1ΔN4C protein was easily purified by two-step chromatography with a VLP yield of up to 60 mg/L (purity > 99 %), 5-fold that of L1ΔC, whereas L1ΔN8C and L1ΔN13C behaved similarly to L1ΔC either in protein or mRNA expression. Moreover, L1ΔN4C VLPs showed similar binding activities with six HPV58 neutralizing monoclonal antibodies and induced comparable level of neutralizing antibody in mice to that of L1ΔC VLPs. Our results demonstrate that certain N- and C-terminal truncations of HPV58 L1 can enhance VLP yield. This method may be used to reduce production costs of other L1VLPs or chimeric VLPs to developing pan-HPV vaccines using baculovirus system.

Nonvaccine human papillomavirus genotype common in women with HIV failing cervical precancer treatment

OBJECTIVE

The aim of this study was to assess failure after treatment of high-grade cervical intraepithelial neoplasia (CIN2+) by HIV status and human papillomavirus (HPV) type.

DESIGN

A population-based register study.

METHODS

The Swedish National HIV Registry, the Swedish Population Registry and the Swedish National Cervical Screening Registry were linked to identify all women in Stockholm and Gothenburg counties (Sweden) living with HIV and diagnosed with CIN2+ sometime between 1983 and 2014 (n = 179). HIV-negative controls with CIN2+, were matched (2 : 1) for country of birth. CIN2+ biopsies were retrieved from biobanks and genotyped. Absolute risk and adjusted odds ratios (adjOR) of treatment failure by HIV status given HPV type (HPV16/18 vs. non-HPV16/18) were calculated.

RESULTS

HPV16 (32%) and HPV35 (24%) dominated in women living with HIV (WLWH) with failure, HPV35 mainly in women born in sub-Saharan Africa (67%). The absolute risk of failure in women with HPV16/18 was 26% [95% confidence interval (95% CI) 14-44] in WLWH and 12% in HIV-negative (95% CI 7-19). The absolute risk of failure in women with non-HPV16/18 was 20% (95% CI 12-31) in WLWH and 5% in HIV-negative (95% CI 2-11). WLWH with non-HPV16/18 were six times more likely to fail than HIV-negative (adjOR 6.1, 95% CI 2.0-18.6).

CONCLUSION

HPV35, not included in current HPV vaccines, was the second most common type in WLWH with failure. WLWH with non-HPV16/18 were six times more likely to fail than HIV-negative. This could have implications for surveillance and vaccination post CIN2+ treatment, particularly in WLWH from sub-Saharan Africa.

Human Papillomavirus Types Associated with Cervical Dysplasia among HIV- and Non-HIV-Infected Women Attending Reproductive Health Clinics in Eastern Kenya

Background

Human papillomavirus (HPV) causes over 99% of all cervical cancer globally. In 2019, it was responsible for 3286 deaths in Kenya. Data on the epidemiological distribution of HPV genotypes by cervical dysplasia and HIV-infected women which is important in designing prevention strategy monitoring treatment and management of cervical cancer is lacking in Eastern Kenya.

Objective

To determine HPV genotype prevalence and their association with cervical dysplasia among HIV-infected (cases) and noninfected (control) women aged 18-48 years seeking reproductive healthcare.

Methods

A cervical broom was softly rotated 360 degrees five times to exfoliate cells from the region of the transformation zone, squamocolumnar junction, and endocervical canal for HPV genotyping. Social-demographic and risk factors responsible for HPV acquisition were collected using a questionnaire. Laboratory outcome and questionnaire data statistical relationships were computed using Pearson chi-square test.

Results

317 women (cases: 161 (50.8%), control 156 (49.2%), mean age: 34.3,SD ± 10.4, range 18-46 years) were recruited from Embu (85/317 (26.8%)), Isiolo (64/317 (20.2%)), Kirinyaga (56/317 (17.7%)), Meru (81/317 (25.6%)), and Tharaka-Nithi (31/317 (9.8%)). The frequency HPV genotypes detected by cervical dysplasia were CIN1 (cases: HPV81 (12/317 (3.8%)), HPV11 (2/317 (0.6%)); control: HPV53 and 66 coinfection (1/317 (0.3%)), CIN2 (cases: HPV11, HPV16, HPV66 ((1/317 (0.3%) each), HPV81 (6/317 (1.9%)), and single case (1/317 (0.3%)) of HPV11 and 66, HPV81 and 44, HPV81 and 88, HPV9 and 53, and HPV16 and 58 coinfection; control: HPV81 (2/317 (0.6%)) and invasive cervical cancer (cases: HPV16 (1/317 (0.3%)) and HPV81 (3/317 (0.9%)); control: HPV16 and 66 (1/317 (0.3%))).

Conclusions

There was a higher frequency of both high-risk and low-risk HPV genotypes associated with cervical dysplasia among HIV-infected than HIV-uninfected women seeking reproductive health care. This study provides epidemiological data on the existence of nonvaccine HPV types associated with cervical dysplasia in the region.

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.