Global evaluation of lineage-specific human papillomavirus capsid antigenicity using antibodies elicited by natural infection

Human Papillomavirus (HPV) type variants have been classified into lineages and sublineages based upon their whole genome sequence. Here we have examined the specificity of antibodies generated following natural infection with lineage variants of oncogenic types (HPV16, 18, 31, 33, 45, 52 and 58) by testing serum samples assembled from existing archives from women residing in Africa, The Americas, Asia or Europe against representative lineage-specific pseudoviruses for each genotype. We have subjected the resulting neutralizing antibody data to antigenic clustering methods and created relational antigenic profiles for each genotype to inform the delineation of lineage-specific serotypes. For most genotypes, there was evidence of differential recognition of lineage-specific antigens and in some cases of a sufficient magnitude to suggest that some lineages should be considered antigenically distinct within their respective genotypes. These data provide compelling evidence for a degree of lineage specificity within the humoral immune response following natural infection with oncogenic HPV.

The impact of over ten years of HPV vaccination in England: Surveillance of type-specific HPV in young sexually active females

INTRODUCTION

The UK national human papillomavirus (HPV) vaccination programme was introduced in 2008 using the bivalent HPV16/18 vaccine, changing to the quadrivalent HPV6/11/16/18 vaccine from 2012. We provide an analysis of type-specific HPV prevalence in young sexually active females in England to end 2020 (when the first routinely HPV vaccinated females were reaching 25 years of age and entering the National Health Service Cervical Screening Programme), showing the impact of over ten years of high coverage HPV vaccination.

METHODS

Residual vulvovaginal swabs (VVS) were collected from 16 to 24 year old women attending for chlamydia screening between 2010 and 2020, anonymised and tested for type-specific HPV DNA. Trends in vaccine and non-vaccine HPV type prevalence were compared over time and association with vaccination coverage was evaluated within the post-vaccination period.

RESULTS

A total of 21,168 eligible VVS specimens were tested for HPV DNA. The prevalence of HPV16/18 in sexually active 16-18 year old females who were offered vaccination aged 12-13 years was <1% in the most recent years tested, compared to over 15% prior to the vaccination programme in 2008. The magnitude of these decreases also suggests reduced transmission is offering some herd protection to unvaccinated females. HPV31/33/45 prevalence also steadily decreased, providing evidence of cross-protection. HPV6/11 prevalence remained stable during the bivalent vaccine period, with more recent declines, as expected due to the use of the quadrivalent vaccine. There has been no substantive increase in the prevalence of other high-risk (HR) HPV types.

DISCUSSION

More than ten years of high coverage HPV vaccination in adolescent females in England has delivered dramatic declines in the prevalence of HPV vaccine-types and closely related HPV types in females in the vaccine eligible age group, and no indication of type replacement. These findings should enable confidence in planning for cervical screening of these females, and in predicting declines in HPV-related cancers.

Contribution of Surface-Exposed Loops on the HPV16 Capsid to Antigenic Domains Recognized by Vaccine or Natural Infection Induced Neutralizing Antibodies

Human papillomavirus (HPV) is the causative agent of cervical and other cancers and represents a significant global health burden. HPV vaccines demonstrate excellent efficacy in clinical trials and effectiveness in national immunization programmes against the most prevalent genotype, HPV16. It is unclear whether the greater protection conferred by vaccine-induced antibodies, compared to natural infection antibodies, is due to differences in antibody magnitude and/or specificity. We explore the contribution of the surface-exposed loops of the major capsid protein to antigenic domains recognized by vaccine and natural infection neutralizing antibodies. Chimeric pseudoviruses incorporating individual (BC, DE, EF, FG, HI) or combined (All: BC/DE/EF/FG/HI) loop swaps between the target (HPV16) and control (HPV35) genotypes were generated, purified by ultracentrifugation and characterized by SDS-PAGE and electron microscopy. Neutralizing antibody data were subjected to hierarchical clustering and outcomes modeled on the HPV16 capsomer crystal model. Vaccine antibodies exhibited an FG loop preference followed by the EF and HI loops while natural infection antibodies displayed a more diverse pattern, most frequently against the EF loop followed by BC and FG. Both vaccine and natural infection antibodies demonstrated a clear requirement for multiple loops. Crystal modeling of these neutralizing antibody patterns suggested natural infection antibodies typically target the outer rim of the capsomer while vaccine antibodies target the central ring around the capsomer lumen. Chimeric pseudoviruses are useful tools for probing vaccine and natural infection antibody specificity. These data add to the evidence base for the effectiveness of an important public health intervention. IMPORTANCE The human papillomavirus type 16 (HPV16) major virus coat (capsid) protein is a target for antibodies induced by both natural infection and vaccination. Vaccine-induced immunity is highly protective against HPV16-related infection and disease while natural infection associated immunity significantly less so. For this study, we created chimeric functional pseudoviruses based upon an antigenically distant HPV genotype (HPV35) resistant to HPV16-specific antibodies with inserted capsid surface fragments (external loops) from HPV16. By using these chimeric pseudoviruses in functional neutralization assays we were able to highlight specific and distinct areas on the capsid surface recognized by both natural infection and vaccine induced antibodies. These data improve our understanding of the difference between natural infection and vaccine induced HPV16-specific immunity.

Multiplex Human Papillomavirus L1L2 virus-like particle antibody binding assay

A variety of in vitro techniques are available to estimate the level of antibodies present in human serum samples. Such tests are highly specific and are used to determine prior exposure to a pathogen or to estimate the magnitude, breadth and durability of individual and population level vaccine immunity. Multiplex (or multi-analyte) platforms are increasingly being used to evaluate immune responses against multiple antigens at the same time, usually at reduced per sample cost and a more efficient use of available samples. Consequently, multiplex serology is an essential component of a wide range of public health programmes. Human papillomavirus (HPV) serology is limited to a small number of academic, public health and vaccine manufacturer laboratories globally. Such platforms include indirect binding to the major (L1) capsid protein virus-like particles (VLP), monoclonal antibody competition against L1 VLP and indirect binding to L1 and L2 (minor capsid protein) VLP on multiplex (Luminex®, Meso Scale Discovery®) and standard (ELISA) platforms. The methodology described here utilizes a common multi-analyte platform and L1L2-based VLP expressed in house, which allows the simultaneous detection and quantification of antibody responses against nine vaccine-relevant HPV genotypes.

Abstract 61: Factors Related to Human Papillomavirus Vaccine Uptake and Acceptability in Manizales, Colombia, 2017-2019: A Population-Based Study of the 2003, 2004 and 2005 Birth Cohorts

Purpose: The first 2 rounds (2012-2013) of the Colombian school-based HPV vaccination program attained 80% coverage of nine-year-old girls. After a psychogenic event in 2014 in a town of the Caribbean region, vaccination fell nationwide to 20% in 2016. We identified factors associated to decreasing coverage of the HPV vaccination program in Manizales, Colombia.

Methods: Structured questionnaires based on the HPV health belief model (HBM) were used in a population-based survey (September 2017-February 2019) to privately interview girls from birth cohorts of 2003, 2004 and 2005 and their parents. Vaccination coverage (at least one dose) was defined by the Expanded Program of Immunization Registry, HPV 6/11/16/18 serology and parents and girls self-report. Multivariable adjusted Prevalence Ratios (aPR) and 95% confidence intervals were estimated using complementary log-log regression to identify sociodemographic factors associated to coverage and changes in HBM constructs scores associated to acceptability of the HPV vaccine.

Results: 1.287 of 1.299 eligible girls and their parents completed the survey, 99% were school-registered and 97% urban area residents. The vaccine coverage was 93.4% (394/422), 84% (356/424), and 63% (279/441) for the 2003, 2004, and 2005 birth cohorts, respectively. High educational level in parents was associated with decreased HPV vaccine coverage (aPR 0.80, 95%CI 0.66-0.95). The perceived benefits increased (aPR 1.22, 95%CI 1.18-1.27 for parents; aPR 1.25, 95%CI 1.21-1.29 for girls) meanwhile, the perceived barriers (negative recommendation by family/friends, news about vaccine adverse events and health system and school barriers) decreased (aPR 0.73 95%CI 0.69-0.77 for parents; aPR 0.84 95%CI 0.79-0.88 for girls) the acceptability of HPV vaccine. Birth year (2005) and high socioeconomic status were also associated with decrease acceptability.

Conclusion: Perceived barriers were associated to decreased acceptability and coverage of vaccination in the first 3 rounds of the national HPV vaccination program in Manizales, Colombia.

Citation Format: Karen Cárdenas-Garzón, Maria Cecilia Agudelo, Olga Lucia Tovar-Aguirre, Sandra Franco, Kelly Paola Valverde, Nelson Arias, Difariney Gonzalez, Nilton E. Montoya, Maria Patricia Arbelaez, Isabel Cristina Garces-Palacio, Karly Louie, Simon Beddows, Gloria Sanchez. Factors Related to Human Papillomavirus Vaccine Uptake and Acceptability in Manizales, Colombia, 2017-2019: A Population-Based Study of the 2003, 2004 and 2005 Birth Cohorts. [abstract]. In: Proceedings of the 9th Annual Symposium on Global Cancer Research; Global Cancer Research and Control: Looking Back and Charting a Path Forward; 2021 Mar 10-11. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2021;30(7 Suppl):Abstract nr 61.

Post-vaccination HPV seroprevalence among female sexual health clinic attenders in England

BACKGROUND

The National HPV Immunisation Programme was introduced in England in September 2008 using the HPV16/18 bivalent vaccine. We conducted serological surveillance to explore vaccination coverage levels. We also conducted a case-control study to investigate a hypothesised cross-protective effect of the HPV16/18 vaccine against genital warts.

METHODS

Residual serum specimens from 16 to 20 year-old women attending six specialist sexual health services (SSHS) between 2011 and 2015 in England were tested for antibodies against HPV16 and HPV18 using a virus-like particle (VLP)-based multiplex serology assay. Patients were classified as having vaccine-induced seropositivity if they were seropositive for both HPV types and either had high antibody levels for at least one HPV type, or moderately high levels for both HPV types. Differences in vaccine-induced seropositivity by patient characteristics were investigated using logistic regression. Vaccine-induced seropositivity was then compared for patients with genital warts (cases) and matched patients without (controls).

RESULTS

Of 3,973 serum specimens collected, 3,870 (97.4%) had a valid result. The proportion of women with vaccine-induced seropositivity decreased with age (from 78.1% in 16-year-olds to 52.6% in 20-year-olds). Vaccine-induced seropositivity was lower among women born outside the UK, from more deprived areas and with a history of chlamydia diagnosis. A difference in uptake by ethnic group was also seen but this was largely confounded by differences in deprivation and country of birth. Among 537 cases and 1,515 controls, there was little evidence of a protective effect of the bivalent HPV vaccine against genital warts (adjusted odds ratio 0.93; 95% CI: 0.74-1.18).

DISCUSSION

Vaccine-induced seropositivity in this high-risk population was in line with vaccination coverage in the general population although was lower in some at-risk sub-groups. This study does not provide evidence to support a cross-protective effect of the HPV16/18 vaccine against genital warts.

HPV16 and HPV18 seropositivity and DNA detection among men who have sex with men: a cross-sectional study conducted in a sexual health clinic in London

Objectives

Men who have sex with men (MSM) have an increased risk of human papillomavirus (HPV) infection and related diseases compared with men who have sex exclusively with women. From April 2018, there has been a phased roll-out of HPV vaccination offered to MSM aged up to 45 years old who are attending sexual health clinics and HIV clinics in England. The vaccine is most effective if delivered prior to HPV infection. We estimated the proportion of MSM with no current vaccine-type infection and no serological evidence of prior infection, in a study undertaken prior to vaccine introduction.

Methods

We conducted a cross-sectional study among 484 MSM aged 18–40 years old who attended a sexual health clinic in London between 2010 and 2012. We estimated the prevalence of current and past infection by testing for HPV DNA in anogenital samples and for serum antibodies to HPV16 and HPV18.

Results

The median age was 30 years (IQR 25–35). The prevalence of HPV16 and HPV18 DNA was 13.2% and 6.2%, respectively. Seropositivity for HPV16 and HPV18 was 28.5% and 17.1%, respectively, with 11.4% seropositive for both types. Seropositivity for the same HPV type was strongly associated with anogenital DNA detection. 279 MSM (57.6%) tested negative for both HPV16 and HPV18 serology and were DNA negative for these two types; only 5 MSM (1.0%) were seropositive and DNA positive for both HPV types.

Conclusions

This is the first study to determine both the prevalence of HPV DNA in anogenital samples and HPV seroprevalence among MSM attending a sexual health clinic in the UK. Over half of MSM in this study had no evidence of a previous or current infection with either of the high-risk HPV types included in the quadrivalent vaccine, which supports the rationale for opportunistic HPV vaccination of MSM attending sexual health clinics.

Performance of human papillomavirus DNA detection in residual specimens taken for Chlamydia trachomatis and Neisseria gonorrhoeae nucleic acid amplification testing in men who have sex with men

OBJECTIVES

Rectal swab specimens, either alone or pooled with first-void urine (FVU) and pharyngeal swab specimens, are used to test for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infection in men who have sex with men (MSM). Following introduction of human papillomavirus (HPV) vaccination for MSM attending UK sexual health services (SHSs), HPV testing of residual CT/NG test specimens has been proposed to monitor HPV prevalence in this population. Performance of HPV detection in such specimens has not been evaluated previously.

METHODS

MSM attending a UK SHS provided three specimens: (1) rectal swab for CT/NG, (2) pooled rectal/pharyngeal/FVU specimen for CT/NG and (3) dedicated anal swab for HPV. Specimen 3 and residual material from specimens 1 and 2 were tested for type-specific HPV DNA. HPV detection was by an in-house multiplex PCR and luminex-based genotyping assay.

RESULTS

A total of 129 MSM were recruited with a mean age of 38.1 years; 24% were HIV-positive. Of the 129 MSM, 92 (71%) had any type-specific HPV DNA in ≥1 specimen; 80 (62%) had high risk (HR) HPV. Of 123 participants with sufficient residual pooled and dedicated specimens, 70 (56.9%) had detectable HPV on both, and 40 (32.5%) were negative on both; overall concordance was 89% (95% CI 83% to 94%), and kappa statistic was 0.78 (95% CI 0.66 to 0.89). Pooled samples had a 4.1% (95% CI -1.9% to 10.0%) higher test positivity rate than dedicated samples.Of 125 participants with sufficient residual rectal and specimens, 74 (59.2%) had detectable HPV on both, and 36 (28.8%) were negative on both; overall concordance was 88% (95% CI 81% to 93%), and kappa statistic was 0.74 (95% CI 0.61 to 0.86). Residual rectal samples had 5.6% (95%CI -0.6% to 11.8%) higher test positivity than dedicated samples.

CONCLUSIONS

We observed high concordance between the dedicated and residual STI test specimens. Our data support the strategy of testing residual specimens for HPV prevalence monitoring in MSM to evaluate the impact of the targeted vaccination programme.

Human papillomavirus (HPV) vaccination and oropharyngeal HPV in ethnically diverse, sexually active adolescents: community-based cross-sectional study

Objectives

Oropharyngeal squamous cell carcinoma is the most common human papillomavirus (HPV)-associated cancer in the UK, but little is known about the prevalence of oropharyngeal HPV in sexually active teenagers. We investigated reported HPV vaccination coverage (in females) and prevalence of oropharyngeal HPV in sexually active students attending six technical colleges in London, UK.

Methods

In 2017, we obtained mouthwash samples and questionnaires from male and female students taking part in the ‘Test n Treat’ chlamydia screening trial. Samples were subjected to HPV genotyping.

Results

Of 232 participants approached, 202 (87%) provided a mouthwash sample and questionnaire. Participants’ median age was 17 years and 47% were male. Most (73%) were from black and minority ethnic groups, 64% gave a history of oral sex, 52% reported having a new sexual partner in the past 6 months, 33% smoked cigarettes, 5.9% had concurrent genitourinary Chlamydia trachomatis infection and 1.5% Neisseria gonorrhoeae and 5.0% were gay or bisexual. Only 47% (50/107) of females reported being vaccinated against HPV 16/18, of whom 74% had received ≥2 injections. HPV genotyping showed three mouthwash samples (1.5%, 95% CI 0.3% to 4.3%) were positive for possible high-risk human papillomavirus (HR-HPV), one (0.5%, 0.0% to 2.7%) for low-risk HPV 6/11, but none (0.0%, 0.0% to 1.8%) for HR-HPV. Four samples (2.0%, 0.5% to 5.0%) were positive for HPV16 using a HPV16 type-specific quantitative PCR, but these were at a very low copy number and considered essentially negative.

Conclusions

Despite the high prevalence of oral sex and genitourinary chlamydia and low prevalence of HPV vaccination, the prevalence of oropharyngeal HR-HPV in these adolescents was negligible.

Antimicrobial resistance in Mycoplasma genitalium sampled from the British general population

BACKGROUND

Mycoplasma genitalium is a common sexually transmitted infection. Treatment guidelines focus on those with symptoms and sexual contacts, generally with regimens including doxycycline and/or azithromycin as first-line and moxifloxacin as second-line treatment. We investigated the prevalence of antimicrobial resistance (AMR)-conferring mutations in M. genitalium among the sexually-active British general population.

METHODS

The third national survey of sexual attitudes and lifestyles (Natsal-3) is a probability sample survey of 15 162 men and women aged 16-74 years in Britain conducted during 2010-12. Urine test results for M. genitalium were available for 4507 participants aged 16-44 years reporting >1 lifetime sexual partner. In this study, we sequenced regions of the 23S rRNA and parC genes to detect known genotypic determinants for resistance to macrolides and fluoroquinolones respectively.

RESULTS

94% (66/70) of specimens were re-confirmed as M. genitalium positive, with successful sequencing in 85% (56/66) for 23S rRNA and 92% (61/66) for parC genes. Mutations in 23S rRNA gene (position A2058/A2059) were detected in 16.1% (95%CI: 8.6% to 27.8%) and in parC (encoding ParC D87N/D87Y) in 3.3% (0.9%-11.2%). Macrolide resistance was more likely in participants reporting STI diagnoses (past 5 years) (44.4% (18.9%-73.3%) vs 10.6% (4.6%-22.6%); p=0.029) or sexual health clinic attendance (past year) (43.8% (23.1%-66.8%) vs 5.0% (1.4%-16.5%); p=0.001). All 11 participants with AMR-conferring mutations had attended sexual health clinics (past 5 years), but none reported recent symptoms.

CONCLUSIONS

This study highlights challenges in M. genitalium management and control. Macrolide resistance was present in one in six specimens from the general population in 2010-2012, but no participants with AMR M. genitalium reported symptoms. Given anticipated increases in diagnostic testing, new strategies including novel antimicrobials, AMR-guided therapy, and surveillance of AMR and treatment failure are recommended.

Comprehensive evaluation of the antigenic impact of intra-genotypic human papillomavirus variant diversity on recognition by neutralizing monoclonal antibodies raised against lineage a L1 virus like particles

Introduction. Naturally-occurring variants of Human papillomavirus (HPV) genotypes have been defined as lineages and sub-lineages, but little is known about the impact of this diversity on protein function. We have previously demonstrated that variation within the major (L1) and minor (L2) capsid proteins impact the susceptibility of HPV to serum antibodies elicited by vaccination and natural infection. Higher resolution mapping of variant residues, however, requires the availability of appropriate tools, such as type-specific monoclonal antibodies (MAbs). These empirical data will improve our understanding of the consequences of natural variation on capsid antigenicity.

Methods. We investigated the susceptibility of 37 representative pseudovirus variants of HPV16, HPV18, HPV31, HPV33, HPV45, HPV52 and HPV58 to neutralization by type-specific murine MAbs raised against the A lineage of their respective genotypes. Homology models derived from available HPV L1 crystal structures were generated to permit mapping of variant residues onto the surface-exposed L1 protein for relevant variants

Results. Type-specific lineage A-specific MAbs demonstrated differential reactivity against some, but not all, variants within its respective genotype. Some of these differences were minor (<4 fold) while some variants displayed orders of magnitude reduced sensitivity. These differences in antigenicity were mapped to a limited number of variant residues on the capsid surface.

Conclusions. These data contribute to our understanding of HPV L1 variant antigenicity and may have implications for seroprevalence or vaccine immunity studies based upon L1 antigens.

Sensitivity of Human Papillomavirus (HPV) Lineage and Sublineage Variant Pseudoviruses to Neutralization by Nonavalent Vaccine Antibodies

Natural variants of human papillomavirus (HPV) are classified into lineages and sublineages based upon whole-genome sequence, but the impact of diversity on protein function is unclear. We investigated the susceptibility of 3–8 representative pseudovirus variants of HPV16, HPV18, HPV31, HPV33, HPV45, HPV52, and HPV58 to neutralization by nonavalent vaccine (Gardasil®9) sera. Many variants demonstrated significant differences in neutralization sensitivity from their consensus A/A1 variant but these were of a low magnitude. HPV52 D and HPV58 C variants exhibited >4-fold reduced sensitivities compared to their consensus A/A1 variant and should be considered distinct serotypes with respect to nonavalent vaccine-induced immunity.

Impact of Naturally Occurring Variation in the Human Papillomavirus 58 Capsid Proteins on Recognition by Type-Specific Neutralizing Antibodies

Background

Naturally occurring variants of human papillomavirus (HPV) 58 have been defined as lineages and sublineages but little is known about the impact of this diversity on protein function. We investigated the impact of variation within the major (L1) and minor (L2) capsid proteins of HPV58 on susceptibility to neutralizing antibodies.

Methods

Pseudovirus (PsV) representing A1, A2, A3, B1, B2, C, D1, and D2 variants were evaluated for their susceptibility to antibodies elicited during natural infection, preclinical antisera generated against virus-like particles, and monoclonal antibodies (MAbs).

Results

Lineage C PsV demonstrated a decreased sensitivity to antibodies raised against lineage A antigens. Exchange of the DE, FG, and/or HI loops between sublineage A1 and lineage C demonstrated that residues within all 3 loops were essential for the differential sensitivity to natural infection antibodies, with slightly different requirements for the animal antisera and MAbs. Comparison between the HPV58 A1 L1 pentamer crystal structure and an HPV58 C homology model indicated that these differences in neutralization sensitivity were likely due to subtle epitope sequence changes rather that major structural alterations.

Conclusions

These data improve our understanding of the impact of natural variation on HPV58 capsid antigenicity and raise the possibility of lineage-specific serotypes.

Epidemiology of genital warts in the British population: implications for HPV vaccination programmes

OBJECTIVES

To estimate the prevalence of, and describe risk factors for, genital warts (GWs) in the British population, following the introduction of the bivalent (human papillomavirus (HPV)-16/18) vaccination programme in girls, and prior to the switch to quadrivalent (HPV-6/11/16/18) vaccine (offering direct protection against GWs) and compare this with GW diagnoses in the prevaccination era.

METHODS

Natsal-3, a probability sample survey in Britain, conducted in 2010-2012, interviewed 9902 men and women aged 16-44. Natsal-2, conducted in 1999-2001, surveyed 11 161 men and women aged 16-44. Both surveys collected data on sexual behaviour and sexually transmitted infection diagnoses using computer-assisted interview methods.

RESULTS

In Natsal-3, 3.8% and 4.6% of sexually experienced men and women reported ever having a diagnosis of GWs, with 1.3% of men and 1.7% of woman reporting a GWs diagnosis in the past 5 years. GWs were strongly associated with increasing partner numbers and condomless sex. Diagnoses were more frequent in men who have sex with men (MSM) (11.6% ever, 3.3% past 5 years) and in women reporting sex with women (10.8% ever, 3.6% past 5 years). In the age group who were eligible for vaccination at the time of Natsal-3 (16-20 years), a similar proportion of same-aged women reported a history of GWs in Natsal-2 (1.9%, 1.1-3.4) and Natsal-3 (2.6%, 1.5-4.4).

CONCLUSIONS

These data provide essential parameters for mathematical models that inform cost-effectiveness analyses of HPV vaccination programmes. There was no evidence of population protection against GWs conferred by the bivalent vaccine. Even with vaccination of adolescent boys, vaccination should be offered to MSM attending sexual health clinics.

Durability of the neutralizing antibody response to vaccine and non-vaccine HPV types 7 years following immunization with either Cervarix® or Gardasil® vaccine

Bivalent (Cervarix®) and quadrivalent (Gardasil®) Human Papillomavirus (HPV) vaccines demonstrate remarkable efficacy against the targeted genotypes, HPV16 and HPV18, but also a degree of cross-protection against non-vaccine incorporated genotypes, HPV31 and HPV45. These outcomes seem to be supported by observations that the HPV vaccines induce high titer neutralizing antibodies against vaccine types and lower responses against non-vaccine types. Few data are available on the robustness of the immune response against non-vaccine types. We examined the durability of vaccine and non-vaccine antibody responses in a follow up of a head-to-head study of 12-15 year old girls initially randomized to receive three doses of Cervarix® or Gardasil® vaccine. Neutralizing antibodies against both vaccine and non-vaccine types remained detectable up to 7 years following initial vaccination and a mixed effects model was used to predict the decline in antibody titers over a 15 year period. The decline in vaccine and non-vaccine type neutralizing antibody titers over the study period was estimated to be 30% every 5-7 years, with Cervarix® antibody titers expected to remain 3-4 fold higher than Gardasil® antibody titers over the long term. The antibody decline rates in those with an initial response to non-vaccine types were similar to that of vaccine types and are predicted to remain detectable for many years. 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. Original trial: ClinicalTrials.gov NCT00956553.

Impact of naturally occurring variation in the human papillomavirus 52 capsid proteins on recognition by type-specific neutralising antibodies

We investigated the impact of naturally occurring variation within the major (L1) and minor (L2) capsid proteins on the antigenicity of human papillomavirus (HPV) type 52 (HPV52). L1L2 pseudoviruses (PsVs) representing HPV52 lineage and sublineage variants A1, A2, B1, B2, C and D were created and tested against serum from naturally infected individuals, preclinical antisera raised against HPV52 A1 and D virus-like particles (VLPs) and neutralising monoclonal antibodies (MAbs) raised against HPV52 A1 VLP. HPV52 lineage D PsV displayed a median 3.1 (inter-quartile range 2.0-5.6) fold lower sensitivity to antibodies elicited following natural infection with, where data were available, HPV52 lineage A. HPV52 lineage variation had a greater impact on neutralisation sensitivity to pre-clinical antisera and MAbs. Chimeric HPV52 A1 and D PsV were created which identified variant residues in the FG (Q281K) and HI (K354T, S357D) loops as being primarily responsible for the reported differential sensitivities. Homology models of the HPV52 L1 pentamer were generated which permitted mapping these residues to a small cluster on the outer rim of the surface exposed pentameric L1 protein. These data contribute to our understanding of HPV L1 variant antigenicity and may have implications for seroprevalence or vaccine immunity studies based upon HPV52 antigens.

Evaluation of Dried Blood Spots and Oral Fluids as Alternatives to Serum for Human Papillomavirus Antibody Surveillance

Human papillomavirus (HPV) vaccination elicits high-titer genotype-specific antibody responses that are associated with a reduced risk of cervical disease caused by vaccine-incorporated genotypes. Our objective was to evaluate dried blood spots (DBSs) and oral mucosal transudate (OMT) as alternative samples to serum to confirm HPV vaccine antibody status. A study was carried out to evaluate the feasibility of detecting HPV16 and HPV18 antibodies in OMT, DBSs, and sera among women who self-reported being unvaccinated or fully vaccinated with the HPV vaccine. Serum had the highest sensitivity (100%) for detection of antibodies against both HPV16 and HPV18 but the lowest specificity, due to the detection of natural infection antibodies in 16% of unvaccinated women. Conversely, DBSs and OMT had lower sensitivity (96% and 82%, respectively) but high specificity (98%). We confirmed that these antibodies were functional (i.e., neutralizing) and that their detection was quantitatively reproducible and well correlated between sample types when normalized to IgG content. DBSs and OMT are appropriate alternative sample types for HPV vaccine surveillance. These alternative sample types warrant consideration for the purposes of cervical screening, diagnosis, and management, but more work will be needed to establish the stringent parameters required for such application.IMPORTANCE Human papillomavirus (HPV) is the causative agent of cervical and other anogenital cancers. HPV vaccination, primarily targeted at young girls before the age of sexual debut, is starting to demonstrate population-level declines in HPV infection and early disease associated with vaccine-incorporated genotypes. Monitoring young women for vaccine-specific antibody is important for vaccine surveillance and may be useful as an adjunct test within a cervical screening context. We evaluated serum, dried blood spots, and oral fluid as potential samples for such applications and report robust measures of diagnostic accuracy. This is the first time a direct comparison of alternative sample types has been made between vaccinated and unvaccinated women for the detection and quantitation of HPV antibodies.

Population-Level Effects of Human Papillomavirus Vaccination Programs on Infections with Nonvaccine Genotypes

We analyzed human papillomavirus (HPV) prevalences during prevaccination and postvaccination periods to consider possible changes in nonvaccine HPV genotypes after introduction of vaccines that confer protection against 2 high-risk types, HPV16 and HPV18. Our meta-analysis included 9 studies with data for 13,886 girls and women ≤19 years of age and 23,340 women 20-24 years of age. We found evidence of cross-protection for HPV31 among the younger age group after vaccine introduction but little evidence for reductions of HPV33 and HPV45. For the group this same age group, we also found slight increases in 2 nonvaccine high-risk HPV types (HPV39 and HPV52) and in 2 possible high-risk types (HPV53 and HPV73). However, results between age groups and vaccines used were inconsistent, and the increases had possible alternative explanations; consequently, these data provided no clear evidence for type replacement. Continued monitoring of these HPV genotypes is important.

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.

Seropositivity to non-vaccine incorporated genotypes induced by the bivalent and quadrivalent HPV vaccines: A systematic review and meta-analysis

BACKGROUND

Human papillomavirus vaccines have demonstrated remarkable efficacy against persistent infection and disease associated with vaccine-incorporated genotypes and a degree of efficacy against some genetically related, non-vaccine-incorporated genotypes. The vaccines differ in the extent of cross-protection against these non-vaccine genotypes. Data supporting the role for neutralizing antibodies as a correlate or surrogate of cross-protection are lacking, as is a robust assessment of the seroconversion rates against these non-vaccine genotypes.

METHODS

We performed a systematic review and meta-analysis of available data on vaccine-induced neutralizing antibody seropositivity to non-vaccine incorporated HPV genotypes.

RESULTS

Of 304 articles screened, 9 were included in the analysis representing ca. 700 individuals. The pooled estimate for seropositivity against HPV31 for the bivalent vaccine (86%; 95%CI 78-91%) was higher than that for the quadrivalent vaccine (61%; 39-79%; p=0.011). The pooled estimate for seropositivity against HPV45 for the bivalent vaccine (50%; 37-64%) was also higher than that for the quadrivalent vaccine (16%; 6-36%; p=0.007). Seropositivity against HPV33, HPV52 and HPV58 were similar between the vaccines. Mean seropositivity rates across non-vaccine genotypes were positively associated with the corresponding vaccine efficacy data reported from vaccine trials.

CONCLUSIONS

These data improve our understanding of vaccine-induced functional antibody specificity against non-vaccine incorporated genotypes and may help to parameterize vaccine-impact models and improve patient management in a post-vaccine setting.

Human papillomavirus (HPV) in young women in Britain: Population-based evidence of the effectiveness of the bivalent immunisation programme and burden of quadrivalent and 9-valent vaccine types

Background

In 2008, the UK introduced an HPV immunisation programme in girls. Population-based prevalence estimates of bivalent (HPV-16/18), quadrivalent (HPV-6/11/16/18) and 9-valent (HPV-6/11/16/18/31/33/45/52/58) vaccine types, and comparison over time, are needed to monitor impact, evaluate effectiveness and guide decision-making on vaccination strategies.

Methods

The third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) in 2010-12, tested urine for HPV from 2569 sexually-experienced women aged 16–44. We report type-specific HPV prevalence and compare results with 1798 women in Natsal-2 (1999–2001) using age-adjusted prevalence ratios (APR).

Findings

In Natsal-3, 4.2% of women aged 16-44y were positive for HPV‐16/18 and 2.9% for HPV-6/11. In 16–20 year olds, 4.5%, 10.8% and 20.7% had at least one bivalent, quadrivalent or 9-valent vaccine type, respectively. Three-dose vaccine coverage was 52.0% in women aged 18-20y. In this age group, HPV-16/18 prevalence was lower in Natsal-3 than Natsal-2 (5.8% vs 11.2%; APR=0.48[95%CI: 0.24–0.93]), however, prevalences of HPV-6/11, HPV-31/33/45 and HPV-52/58 were unchanged. HPV-16/18 prevalence was also unchanged in women aged 21-44y (APR=0.85[0.61–1.19]).

Interpretation

These probability surveys provide evidence of the impact of the bivalent immunisation programme. Reductions were specific to HPV-16/18 and to the age group eligible for vaccination. However, substantial vaccine-preventable HPV remains.

The DE and FG loops of the HPV major capsid protein contribute to the epitopes of vaccine-induced cross-neutralising antibodies

The human papillomavirus (HPV) vaccines consist of major capsid protein (L1) virus-like particles (VLP) and are highly efficacious against the development of cervical cancer precursors attributable to oncogenic genotypes, HPV16 and HPV18. A degree of vaccine-induced cross-protection has also been demonstrated against genetically-related genotypes in the Alpha-7 (HPV18-like) and Alpha-9 (HPV16-like) species groups which is coincident with the detection of L1 cross-neutralising antibodies. In this study the L1 domains recognised by inter-genotype cross-neutralising antibodies were delineated. L1 crystallographic homology models predicted a degree of structural diversity between the L1 loops of HPV16 and the non-vaccine Alpha-9 genotypes. These structural predictions informed the design of chimeric pseudovirions with inter-genotype loop swaps which demonstrated that the L1 domains recognised by inter-genotype cross-neutralising antibodies comprise residues within the DE loop and the late region of the FG loop. These data contribute to our understanding of the L1 domains recognised by vaccine-induced cross-neutralising antibodies. Such specificities may play a critical role in vaccine-induced cross-protection.

Trichomonas vaginalis infection is uncommon in the British general population: implications for clinical testing and public health screening

INTRODUCTION

Variable use of new molecular assays, asymptomatic infections and a lack of population data mean that the population burden of Trichomonas vaginalis is uncertain. We investigated the age-specific prevalence of T. vaginalis within the sexually active British general population to inform testing strategies.

METHODS

Britain's third National Survey of Sexual Attitudes and Lifestyle (Natsal-3) is a probability sample survey of 15 162 individuals aged 16-74 years, undertaken during 2010-2012. Urine from 4386 participants aged 16-44 years reporting ≥1 lifetime sexual partner was tested for T. vaginalis using in-house real-time PCR.

RESULTS

Urinary T. vaginalis was detected in seven women and no men providing urine samples, giving a weighted prevalence estimate of 0.3% (95% CI 0.1% to 0.5%) in sexually experienced women aged 16-44 years. Of the seven women with T. vaginalis detected, four were of black or mixed ethnicity (prevalence 2.7% (0.9% to 7.7%) in this group) and five reported recent partners of black or mixed ethnicity. Six of the women reported symptoms, and five reported sexual health clinic attendance in the past 5 years (prevalence in those reporting clinic attendance: 1.0% (0.4% to 2.3%)). The prevalence of a self-reported history of T. vaginalis (past 5 years) was 0.1% (0.0% to 0.2%) in women and 0.0% (0.0% to 0.2%) in men aged 16-44 years.

CONCLUSIONS

Our British population prevalence estimates indicate that T. vaginalis is a rare infection. These data support policies that restrict asymptomatic screening for T. vaginalis and suggest deployment of molecular tests should be focused within clinical settings and guided by symptoms and local demography.

Epidemiology of Mycoplasma genitalium in British men and women aged 16–44 years: evidence from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3)

Background: There are currently no large general population epidemiological studies of Mycoplasma genitalium (MG), which include prevalence, risk factors, symptoms and co-infection in men and women across a broad age range.

Methods: In 2010-–12, we conducted the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3), a probability sample survey in Britain. Urine from 4507 sexually-experienced participants, aged 16–44 years, was tested for MG.

Results: MG prevalence was 1.2% [95% confidence interval (CI): 0.7–1.8%] in men and 1.3% (0.9–1.9%) in women. There were no positive MG tests in men aged 16–19, and prevalence peaked at 2.1% (1.2–3.7%) in men aged 25–34 years. In women, prevalence was highest in 16–19 year olds, at 2.4% (1.2–4.8%), and decreased with age. Men of Black ethnicity were more likely to test positive for MG [adjusted odds ratio (AOR) 12.1; 95% CI: 3.7–39.4). For both men and women, MG was strongly associated with reporting sexual risk behaviours (increasing number of total and new partners, and unsafe sex, in the past year). Women with MG were more likely to report post-coital bleeding (AOR 5.8; 95%CI 1.4–23.3). However, the majority of men (94.4%), and over half of women (56.2%) with MG did not report any sexually transmitted infection (STI) symptoms. Men with MG were more likely to report previously diagnosed gonorrhoea, syphilis or non-specific urethritis, and women previous trichomoniasis.

Conclusions: This study strengthens evidence that MG is an STI. MG was identified in over 1% of the population, including in men with high-risk behaviours in older age groups that are often not included in STI prevention measures.

Oral Human Papillomavirus Infection in Men Who Have Sex with Men: A Systematic Review and Meta-Analysis

BACKGROUND

The epidemiology of oral human papillomavirus (HPV) infection in men who have sex with men (MSM) differs from anogenital HPV infection. The impact of HPV vaccination has, to date, largely focussed on anogenital outcomes. Vaccination of MSM in the UK has been recommended and, if implemented, baseline estimates of oral HPV prevalence will be useful.

METHODS

We searched Medline, Embase and psycINFO databases for studies reporting prevalence, incidence, and clearance of oral HPV infection in MSM. We performed a random-effects meta-analysis and meta-regression on prevalence estimates and summarised within-study risk factors for oral HPV DNA detection and incidence/clearance rates. We also performed a meta-analysis of the effect of MSM on oral HPV prevalence compared to heterosexual men.

RESULTS

26 publications were identified. The pooled prevalence of oral HPV16 from twelve estimates was 3.0% (95%CI 0.5-5.5) in HIV-negative and 4.7% (95%CI 2.1-7.3) in HIV-positive MSM. Median age of study participants explained 38% of heterogeneity (p<0.01) in HPV prevalence estimates (pooled = 17% and 29% in HIV-negative and HIV-positive, respectively; 22 estimates). Nine studies compared MSM to heterosexual men and found no difference in oral HPV prevalence (pooled OR 1.07 (95%CI 0.65-1.74)). The clearance rate was higher than incidence within studies. Type-specific concordance between oral and anogenital sites was rare.

CONCLUSION

There was substantial heterogeneity between estimates of oral HPV prevalence in MSM populations that was partly explained by HIV status and median age.

HIV Replication in CD4-Negative Cell Lines: Effect of Cloning, CD4 Expression and Inhibition by Dextrin Sulphate

HIV-1 infects CD4 negative (CD4) cell lines with low efficiency. Infected CD4 cells have a low copy number of HIV proviruses per cell and require a high multiplicity of infection. Following CD4 transfection, most human cell lines permit high efficiency HIV entry and replication. We have compared entry and inhibition of HIV-1 into CD4 cells and their equivalent CD4 positive (CD4+) transfectants. Entry of HIV-1 into both CD4+ and CD4− was completely inhibited by a novel sulphated polysaccharide, dextrin sulphate (DS) at 100 μg ml−1, whereas anti-CD4 antibodies only inhibited HIV infection of CD4+ cells. One glial cell line, U251SP-CD4, expressed surface CD4, but this did not increase HIV-1 susceptibility compared to the CD4− U251SP cell line. Subclones of the CD4− cell lines TE671 and U251SP were no more permissive for infection than their corresponding parental line. HIV-1 infected CD4− cells have a significantly lower provirus copy number than CD4+ cells, confirming that the block to HIV-1 replication is predominantly at entry. The action of DS was examined in conjunction with soluble recombinant CD4 (srCD4); DS was found to potentiate the inhibiting effect of srCD4.

Continuing reductions in HPV 16/18 in a population with high coverage of bivalent HPV vaccination in England: an ongoing cross-sectional study

OBJECTIVES

The human papillomavirus (HPV) immunisation programme in England was introduced in 2008. Monitoring changes in type-specific HPV prevalence allows assessment of the population impact of this vaccination programme.

METHODS

Residual vulva-vaginal swab specimens were collected from young sexually active women (aged 16-24 years) attending for chlamydia screening across England. Specimens were collected between 2010 and 2013 for type-specific HPV-DNA testing. HPV prevalence was compared to a similar survey conducted in 2008 prior to the introduction of HPV vaccination.

RESULTS

A total of 7321 specimens collected in the postvaccination period, and 2354 specimens from the prevaccination period were included in this analysis. Among the individuals aged 16-18 years, with an estimated vaccination coverage of 67%, the prevalence of HPV16/18 infection decreased from 17.6% in 2008 to 6.1% in the postvaccination period. Within the postvaccination period, there was a trend towards lower HPV16/18 prevalence with higher vaccination coverage and increasing time since vaccine introduction from 8.5% in the period 2-3 years postvaccination to 4.0% in the period 4-5 years postvaccination. The prevalence of HPV31 reduced from 3.7% in the prevaccination period to 0.9% after vaccine introduction, although this no longer reached statistical significance after additional consideration of the uncertainty due to the assay change. Smaller reductions were seen in the individuals aged 19-21 years with lower estimated vaccination coverage, but there was no evidence of a reduction in the older unvaccinated women. Some overall increase in non-vaccine types was seen in the youngest age groups (ORs (95% CI); 1.3 (1.0 to 1.7) and 1.5 (1.1 to 2.0) for individuals aged 16-18 and 19-21 years, respectively, when adjusted for known population changes and the change in assay) although this should be interpreted with caution given the potential unmasking effect.

CONCLUSIONS

These data demonstrate a reduction in the HPV vaccine types in the age group with the highest HPV vaccination coverage.

Relationship between Humoral Immune Responses against HPV16, HPV18, HPV31 and HPV45 in 12-15 Year Old Girls Receiving Cervarix® or Gardasil® Vaccine

Background

Human papillomavirus (HPV) vaccines confer protection against the oncogenic genotypes HPV16 and HPV18 through the generation of type-specific neutralizing antibodies raised against virus-like particles (VLP) representing these genotypes. The vaccines also confer a degree of cross-protection against HPV31 and HPV45, which are genetically-related to the vaccine types HPV16 and HPV18, respectively, although the mechanism is less certain. There are a number of humoral immune measures that have been examined in relation to the HPV vaccines, including VLP binding, pseudovirus neutralization and the enumeration of memory B cells. While the specificity of responses generated against the vaccine genotypes are fairly well studied, the relationship between these measures in relation to non-vaccine genotypes is less certain.

Methods

We carried out a comparative study of these immune measures against vaccine and non-vaccine genotypes using samples collected from 12–15 year old girls following immunization with three doses of either Cervarix^® or Gardasil^® HPV vaccine.

Results

The relationship between neutralizing and binding antibody titers and HPV-specific memory B cell levels for the vaccine genotypes, HPV16 and HPV18, were very good. The proportion of responders approached 100% for both vaccines while the magnitude of these responses induced by Cervarix^® were generally higher than those following Gardasil^® immunization. A similar pattern was found for the non-vaccine genotype HPV31, albeit at a lower magnitude compared to its genetically-related vaccine genotype, HPV16. However, both the enumeration of memory B cells and VLP binding responses against HPV45 were poorly related to its neutralizing antibody responses. Purified IgG derived from memory B cells demonstrated specificities similar to those found in the serum, including the capacity to neutralize HPV pseudoviruses.

Conclusions

These data suggest that pseudovirus neutralization should be used as the preferred humoral immune measure for studying HPV vaccine responses, particularly for non-vaccine genotypes.

Oral human papillomavirus (HPV) infection in men who have sex with men: prevalence and lack of anogenital concordance

OBJECTIVES

To estimate the prevalence of oral detectable human papillomavirus (HPV) DNA in HIV-negative men who have sex with men (MSM) attending a sexual health clinic in London and concordance with anogenital HPV infection. Such data are important to improve our understanding of the epidemiology of oral HPV and the potential use of vaccines to prevent oropharyngeal cancers.

METHODS

Paired oral rinse samples and anogenital samples were available from 151 HIV-negative MSM within a larger cross-sectional survey. All samples were tested in parallel for 21 types of HPV DNA using an in-house assay.

RESULTS

The median age of participants was 30 (IQR 25-35). The prevalence of any oral HPV and of high-risk HPV (HR-HPV) was 13.7% (n=21; 95% CI 8.7 to 20.2) and 5.9% (n=9; 95% CI 2.7 to 10.9) compared with 64.9% (n=98; 95% CI 56.7 to 72.5) and 34.4% (n=52; 95% CI 26.9 to 42.6) in any anogenital sample, respectively. The prevalence of types prevented by the bivalent (HPV16/18), quadrivalent (HPV6/11/16/18) and nonavalent (HPV6/11/16/18/31/33/45/52/58) vaccines was 1.3% (95% CI 0.2 to 4.7), 2.6% (95% CI 0.7 to 6.6) and 4.6% (95% CI 1.9 to 9.3), respectively. There was no concordance between HPV genotypes detected in oral and anogenital sites.

CONCLUSIONS

HR-HPV DNA, including HPV 16/18, was detected in oral specimens from HIV-negative MSM attending sexual health clinics, suggesting a potential role for vaccination, but is far less common than anogenital infection. How this relates to the risk and natural history of HPV-related head and neck cancers warrants further study. Lack of concordance with anogenital infection also suggests that oral HPV infection should be considered separately when estimating potential vaccine impact.

Human papillomavirus DNA in men who have sex with men: type-specific prevalence, risk factors and implications for vaccination strategies

Background:

Human papillomavirus (HPV) vaccination of girls will have relatively little effect on HPV-related disease in men who have sex with men (MSM). We determined HPV prevalence and risk factors in MSM to inform the potential effectiveness of vaccinating MSM.

Methods:

Cross-sectional study of 522 MSM aged 18–40 attending a London sexual health clinic who completed a computer-assisted self-interview. Urine and two swabs (anal and penile/scrotal/perianal) were collected and tested using an in-house Luminex-based HPV genotyping system.

Results:

Prevalence of DNA of the vaccine-preventable HPV types in ano-genital specimens of men was 87/511 (17.0%), 166/511 (32.5%) and 232/511 (45.4%) for the bivalent (HPV16/18), quadrivalent (HPV6/11/16/18) and nonavalent (HPV6/11/16/18/31/33/45/52/58) vaccine types, respectively. A total of 25.1% had one of the quadrivalent types, and 7.4% had 2+ types. Median age at first anal sex was 19 (IQR 17–23) and at first clinic attendance was 24 (IQR 20–27). The increase in the odds of any HPV infection per year of age was 4.7% (95% CI 1.2–8.4).

Conclusions:

On the basis of the current infection status, most MSM, even among a high-risk population attending a sexual health clinic, are not currently infected with the vaccine-type HPV. A targeted vaccination strategy for MSM in the UK could have substantial benefits.

High-Risk Human Papillomavirus (HPV) Infection and Cervical Cancer Prevention in Britain: Evidence of Differential Uptake of Interventions from a Probability Survey

BACKGROUND

The third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3) provides an opportunity to explore high-risk human papillomavirus (HR-HPV) and uptake of cervical screening and HPV vaccination in the general population.

METHODS

Natsal-3, a probability sample survey of men and women ages 16 to 74, resident in Britain, interviewed 8,869 women in 2010 to 2012. We explored risk factors for HR-HPV (in urine from 2,569 sexually experienced women ages 16 to 44), nonattendance for cervical screening in the past 5 years, and noncompletion of HPV catch-up vaccination.

RESULTS

HR-HPV was associated with increasing numbers of lifetime partners, younger age, increasing area-level deprivation, and smoking. Screening nonattendance was associated with younger and older age, increasing area-level deprivation (age-adjusted OR 1.91, 95% confidence interval, 1.48-2.47 for living in most vs. least deprived two quintiles), Asian/Asian British ethnicity (1.96, 1.32-2.90), smoking (1.97, 1.57-2.47), and reporting no partner in the past 5 years (2.45, 1.67-3.61 vs. 1 partner) but not with HR-HPV (1.35, 0.79-2.31). Lower uptake of HPV catch-up vaccination was associated with increasing area-level deprivation, non-white ethnicity, smoking, and increasing lifetime partners.

CONCLUSIONS

Socioeconomic markers and smoking were associated with HR-HPV positivity, nonattendance for cervical screening, and noncompletion of catch-up HPV vaccination.

IMPACT

The cervical screening program needs to engage those missing HPV catch-up vaccination to avoid a potential widening of cervical cancer disparities in these cohorts. As some screening nonattenders are at low risk for HR-HPV, tailored approaches may be appropriate to increase screening among higher-risk women.

Population-level impact and herd effects following human papillomavirus vaccination programmes: a systematic review and meta-analysis

BACKGROUND

Human papillomavirus (HPV) vaccination programmes were first implemented in several countries worldwide in 2007. We did a systematic review and meta-analysis to assess the population-level consequences and herd effects after female HPV vaccination programmes, to verify whether or not the high efficacy reported in randomised controlled clinical trials are materialising in real-world situations.

METHODS

We searched the Medline and Embase databases (between Jan 1, 2007 and Feb 28, 2014) and conference abstracts for time-trend studies that analysed changes, between the pre-vaccination and post-vaccination periods, in the incidence or prevalence of at least one HPV-related endpoint: HPV infection, anogenital warts, and high-grade cervical lesions. We used random-effects models to derive pooled relative risk (RR) estimates. We stratified all analyses by age and sex. We did subgroup analyses by comparing studies according to vaccine type, vaccination coverage, and years since implementation of the vaccination programme. We assessed heterogeneity across studies using I(2) and χ(2) statistics and we did trends analysis to examine the dose-response association between HPV vaccination coverage and each study effect measure.

FINDINGS

We identified 20 eligible studies, which were all undertaken in nine high-income countries and represent more than 140 million person-years of follow-up. In countries with female vaccination coverage of at least 50%, HPV type 16 and 18 infections decreased significantly between the pre-vaccination and post-vaccination periods by 68% (RR 0·32, 95% CI 0·19-0·52) and anogenital warts decreased significantly by 61% (0·39, 0·22-0·71) in girls 13-19 years of age. Significant reductions were also recorded in HPV types 31, 33, and 45 in this age group of girls (RR 0·72, 95% CI 0·54-0·96), which suggests cross-protection. Additionally, significant reductions in anogenital warts were also reported in boys younger than 20 years of age (0·66 [95% CI 0·47-0·91]) and in women 20-39 years of age (0·68 [95% CI 0·51-0·89]), which suggests herd effects. In countries with female vaccination coverage lower than 50%, significant reductions in HPV types 16 and 18 infection (RR 0·50, 95% CI 0·34-0·74]) and in anogenital warts (0·86 [95% CI 0·79-0·94]) occurred in girls younger than 20 years of age, with no indication of cross-protection or herd effects.

INTERPRETATION

Our results are promising for the long-term population-level effects of HPV vaccination programmes. However, continued monitoring is essential to identify any signals of potential waning efficacy or type-replacement.

FUNDING

The Canadian Institutes of Health Research.

Confirmatory assays are essential when using molecular testing for Neisseria gonorrhoeae in low-prevalence settings: insights from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3)

OBJECTIVES

To investigate the occurrence of unconfirmed positive gonorrhoea results when using molecular testing within a large population-based survey.

DESIGN, SETTING AND PARTICIPANTS

Between 2010 and 2012, we did a probability sample survey of 15,162 men and women aged 16-74 years in Britain. Urine from participants aged 16-44 years reporting ≥1 lifetime sexual partner was tested for Neisseria gonorrhoeae and Chlamydia trachomatis using the Aptima Combo 2 (AC2) assay, with positive or equivocal results confirmed with molecular assays using different nucleic acid targets.

RESULTS

A total of 4550 participants aged 16-44 years had urine test results (1885 men; 2665 women). For gonorrhoea, 18 samples initially tested positive and eight were equivocal. Only five out of 26 confirmed, giving a positive predictive value (PPV) for the initial testing of 19% (95% CI 4% to 34%). Most (86% (18/21)) participants with unconfirmed positive results for gonorrhoea reported zero or one sexual partner without condoms in the past year and none had chlamydia co-infection, whereas all five with confirmed gonorrhoea reported at least two recent sexual partners without condoms, and four had chlamydia co-infection. The weighted prevalence for gonorrhoea positivity fell from 0.4% (0.3% to 0.7%) after initial screening to <0.1% (0.0% to 0.1%) after confirmatory testing. By comparison, 103 samples tested positive or equivocal for chlamydia and 98 were confirmed (PPV=95% (91% to 99%)).

CONCLUSIONS

We highlight the low PPV for gonorrhoea of an unconfirmed reactive test when deploying molecular testing in a low-prevalence population. Failure to undertake confirmatory testing in low-prevalence settings may lead to inappropriate diagnoses, unnecessary treatment and overestimation of population prevalence.

Pre-clinical immunogenicity of human papillomavirus alpha-7 and alpha-9 major capsid proteins

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Comprehensive pre-clinical immunogenicity evaluation of HPV L1 major capsid protein.

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Majority neutralizing antibody response was genotype-specific.

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Reciprocal cross-neutralization between some Alpha-7 and Alpha-9 genotypes.

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Tetravalent formulation (HPV16/18/39/58) induced broadly neutralizing antibodies.

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These data improve our understanding of the antigenic diversity of the L1 protein.

Human papillomavirus (HPV) vaccines confer protection against the oncogenic genotypes HPV16 and HPV18 through the generation of type-specific neutralizing antibodies raised against the constituent virus-like particles (VLP) based upon the major capsid proteins (L1) of these genotypes. The vaccines also confer a degree of cross-protection against some genetically related types from the Alpha-9 (HPV16-like: HPV31, HPV33, HPV35, HPV52, HPV58) and Alpha-7 (HPV18-like: HPV39, HPV45, HPV59, HPV68) species groups. The mechanism of cross-protection is unclear but may involve antibodies capable of recognizing shared inter-genotype epitopes. The relationship(s) between the genetic and antigenic diversity of the L1 protein, particularly for non-vaccine genotypes, is poorly understood.

We carried out a comprehensive evaluation of the immunogenicity of L1 VLP derived from genotypes within the Alpha-7 and Alpha-9 species groups in New Zealand White rabbits and used L1L2 pseudoviruses as the target antigens in neutralization assays.

The majority antibody response against L1 VLP was type-specific, as expected, but several instances of robust cross-neutralization were nevertheless observed including between HPV33 and HPV58 within the Alpha-9 species and between HPV39, HPV59 and HPV68 in the Alpha-7 species. Immunization with an experimental tetravalent preparation comprising VLP based upon HPV16, HPV18, HPV39 and HPV58 was capable of generating neutralizing antibodies against all the Alpha-7 and Alpha-9 genotypes. Competition of HPV31 and HPV33 cross-neutralizing antibodies in the tetravalent sera confirmed that these antibodies originated from HPV16 and HPV58 VLP, respectively, and suggested that they represent minority specificities within the antibody repertoire generated by the immunizing antigen. These data improve our understanding of the antigenic diversity of the L1 protein per se and may inform the rational design of a next generation vaccine formulation based upon empirical data.

Human Papillomavirus 16, 18, 31 and 45 viral load, integration and methylation status stratified by cervical disease stage

Background

Persistent infection with oncogenic Human Papillomavirus (HPV) is associated with the development of cervical cancer with each genotype differing in their relative contribution to the prevalence of cervical disease. HPV DNA testing offers improved sensitivity over cytology testing alone but is accompanied by a generally low specificity. Potential molecular markers of cervical disease include type-specific viral load (VL), integration of HPV DNA into the host genome and methylation of the HPV genome. The aim of this study was to evaluate the relationship between HPV type-specific viral load, integration and methylation status and cervical disease stage in samples harboring HPV16, HPV18, HPV31 or HPV45.

Methods

Samples singly infected with HPV16 (n = 226), HPV18 (n = 32), HPV31 (n = 75) or HPV45 (n = 29) were selected from a cohort of 4,719 women attending cervical screening in England. Viral load and integration status were determined by real-time PCR while 3’L1-URR methylation status was determined by pyrosequencing or sequencing of multiple clones derived from each sample.

Results

Viral load could differentiate between normal and abnormal cytology with a sensitivity of 75% and a specificity of 80% (odds ratio [OR] 12.4, 95% CI 6.2–26.1; p < 0.001) with some variation between genotypes. Viral integration was poorly associated with cervical disease. Few samples had fully integrated genomes and these could be found throughout the course of disease. Overall, integration status could distinguish between normal and abnormal cytology with a sensitivity of 72% and a specificity of 50% (OR 2.6, 95% CI 1.0–6.8; p = 0.054). Methylation levels were able to differentiate normal and low grade cytology from high grade cytology with a sensitivity of 64% and a specificity of 82% (OR 8.2, 95% CI 3.8–18.0; p < 0.001). However, methylation varied widely between genotypes with HPV18 and HPV45 exhibiting a broader degree and higher magnitude of methylated CpG sites than HPV16 and HPV31.

Conclusions

This study lends support for HPV viral load and CpG methylation status, but not integration status, to be considered as potential biomarkers of cervical disease.

Human papillomavirus type 16 long control region and E6 variants stratified by cervical disease stage

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We sequenced HPV16 LCR–E6 variants in cervical disease samples from England.

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98% of variants were of the EUR lineage.

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Site-specific entropy identified several variable sites in the LCR and E6.

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No single or combination of sites were associated with disease, including E6 T350G.

Objective

Certain intra-type variants of HPV16 have been shown to be associated with an increased risk of developing high grade cervical disease, but their potential association is confounded by apparent geographic and phylogenetic lineage dependency. The objective of this study was to evaluate the relationship between HPV16 sequence variants and cervical disease stage in monospecific infection samples from a single lineage (European, EUR) in England.

Methods

One hundred and twelve women singly infected with HPV16 and displaying normal and abnormal cytology grades were selected. An 1187 bp fragment encompassing the entire LCR and a portion of the E6 open reading frame was sequenced to identify intra-type variants. Intra-type diversity was estimated using Shannon entropy.

Results

Almost all samples (110/112; 98%) were assigned to the EUR lineage, one sample was classified as European-Asian (EAS) and another African (Afr1a). The mean pairwise distance of the EUR sequences in this study was low (0.29%; 95%CI 0.13–0.45%) but there were nevertheless several sites in the LCR (n = 5) and E6 (n = 2) that exhibited a high degree of entropy. None of these sites, however, including the T350G non-synonymous (L83V) substitution in E6, alone or in combination, were found to be associated with cervical disease stage.

Conclusions

Despite using single infection samples and samples from a single variant lineage, intra-type variants of HPV16 were not differentially associated with cervical disease. Monitoring intra-lineage, site-specific variants, such as T350G, is unlikely to be of diagnostic value.

Cross-neutralizing antibodies elicited by the Cervarix® human papillomavirus vaccine display a range of Alpha-9 inter-type specificities

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We explored Cervarix^® HPV vaccine cross-reactive antibody specificity.

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L1 VLP binding was a poor surrogate for L1L2 pseudovirus neutralization specificity.

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Cross-neutralizing antibodies comprise a small proportion of total antibody.

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Multiple, overlapping cross-neutralizing antibody specificities exist.

The highly efficacious human papillomavirus (HPV) vaccines contain virus-like particles (VLP) representing genotypes HPV16 and HPV18, which together account for approximately 70% of cervical cancer cases. Vaccine-type protection is thought to be mediated by high titer, type-specific neutralizing antibodies. The vaccines also confer a degree of cross-protection against some genetically-related types from the Alpha-9 (HPV16-like: HPV31, HPV33, HPV35, HPV52, HPV58) and Alpha-7 (HPV18-like: HPV39, HPV45, HPV59, HPV68) species groups. Cross-protection is coincident with the detection of low titer serum responses against non-vaccine types by vaccinees. Such antibodies may be the effectors of cross-protection or their detection may be useful as a correlate or surrogate.

This study evaluated whether cross-neutralization of HPV types from the Alpha-9 species group is mediated by antibodies with a predominantly type-restricted specificity for HPV16 that nevertheless exhibit low affinity interactions with non-vaccine types, or by antibody specificities that demonstrate similar recognition of vaccine and non-vaccine types but are present at very low levels.

Antibodies generated following Cervarix^® vaccination of 13–14 year old girls were evaluated by pseudovirus neutralization, VLP ELISA and by enrichment of target antigen specificity using VLP-immobilized beads. Two-dimensional hierarchical clustering of serology data demonstrated that the antibody specificity profile generated by VLP ELISA was both quantitatively and qualitatively different from the neutralizing antibody specificity profile. Target-specific antibody enrichment demonstrated that cross-neutralization of non-vaccine types was due to a minority of antibodies rather than by the weak interactions of a predominantly type-restricted HPV16 antibody specificity. Furthermore, cross-neutralization of non-vaccine types appeared to be mediated by multiple antibody specificities, recognizing single and multiple non-vaccine types, and whose specificities were not predictable from examination of the serum neutralizing antibody profile. These data contribute to our understanding of the antibody specificities elicited following HPV vaccination and have potential implications for vaccine-induced cross-protection.

Prevalence, risk factors, and uptake of interventions for sexually transmitted infections in Britain: findings from the National Surveys of Sexual Attitudes and Lifestyles (Natsal)

BACKGROUND

Population-based estimates of prevalence, risk distribution, and intervention uptake inform delivery of control programmes for sexually transmitted infections (STIs). We undertook the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) after implementation of national sexual health strategies, and describe the epidemiology of four STIs in Britain (England, Scotland, and Wales) and the uptake of interventions.

METHODS

Between Sept 6, 2010 and Aug 31, 2012, we did a probability sample survey of 15,162 women and men aged 16-74 years in Britain. Participants were interviewed with computer-assisted face-to-face and self-completion questionnaires. Urine from a sample of participants aged 16-44 years who reported at least one sexual partner over the lifetime was tested for the presence of Chlamydia trachomatis, type-specific human papillomavirus (HPV), Neisseria gonorrhoeae, and HIV antibody. We describe age-specific and sex-specific prevalences of infection and intervention uptake, in relation to demographic and behavioural factors, and explore changes since Natsal-1 (1990-91) and Natsal-2 (1999-2001).

FINDINGS

Of 8047 eligible participants invited to provide a urine sample, 4828 (60%) agreed. We excluded 278 samples, leaving 4550 (94%) participants with STI test results. Chlamydia prevalence was 1·5% (95% CI 1·1-2·0) in women and 1·1% (0·7-1·6) in men. Prevalences in individuals aged 16-24 years were 3·1% (2·2-4·3) in women and 2·3% (1·5-3·4) in men. Area-level deprivation and higher numbers of partners, especially without use of condoms, were risk factors. However, 60·4% (45·5-73·7) of chlamydia in women and 43·3% (25·9-62·5) in men was in individuals who had had one partner in the past year. Among sexually active 16-24-year-olds, 54·2% (51·4-56·9) of women and 34·6% (31·8-37·4) of men reported testing for chlamydia in the past year, with testing higher in those with more partners. High-risk HPV was detected in 15·9% (14·4-17·5) of women, similar to in Natsal-2. Coverage of HPV catch-up vaccination was 61·5% (58·2-64·7). Prevalence of HPV types 16 and 18 in women aged 18-20 years was lower in Natsal-3 than Natsal-2 (5·8% [3·9-8·6] vs 11·3% [6·8-18·2]; age-adjusted odds ratio 0·44 [0·21-0·94]). Gonorrhoea (<0·1% prevalence in women and men) and HIV (0·1% prevalence in women and 0·2% in men) were uncommon and restricted to participants with recognised high-risk factors. Since Natsal-2, substantial increases were noted in attendance at sexual health clinics (from 6·7% to 21·4% in women and from 7·7% to 19·6% in men) and HIV testing (from 8·7% to 27·6% in women and from 9·2% to 16·9% in men) in the past 5 years.

INTERPRETATION

STIs were distributed heterogeneously, requiring general and infection-specific interventions. Increases in testing and attendance at sexual health clinics, especially in people at highest risk, are encouraging. However, STIs persist both in individuals accessing and those not accessing services. Our findings provide empirical evidence to inform future sexual health interventions and services.

FUNDING

Grants from the UK Medical Research Council and the Wellcome Trust, with support from the Economic and Social Research Council and the Department of Health.

Reduction in HPV 16/18 prevalence in sexually active young women following the introduction of HPV immunisation in England

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We monitor HPV infection in sexually active young women in England.

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The prevalence of HPV 16/18 has reduced within 3 years of HPV immunisation.

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Reductions in HPV 16/18 were greatest at ages with highest immunisation coverage.

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The data suggest reductions in HPV 16/18 amongst unvaccinated young women and men.

Background

Reduction in the prevalence of vaccine type HPV infection in young women is an early indication of the impact of the HPV immunisation programme and a necessary outcome if the subsequent impact on cervical cancer is to be realised.

Methods

Residual vulva-vaginal swab (VVS) specimens from young women aged 16–24 years undergoing chlamydia screening in community sexual health services (formerly known as family planning clinics), general practice (GP), and youth clinics in 2010–2012 were submitted from 10 laboratories in seven regions around England. These specimens were linked to demographic and sexual behaviour data reported with the chlamydia test, anonymised, and tested for type-specific HPV DNA using a multiplex PCR and Luminex-based genotyping test. Estimated immunisation coverage was calculated and findings were compared to a baseline survey conducted prior to the introduction of HPV immunisation in 2008.

Results

A total of 4664 eligible specimens were collected and 4178 had a valid test result. The post-immunisation prevalence of HPV 16/18 infection was lowest in this youngest age group (16–18 years) and increased with age. This increase with age was a reversal of the pattern seen prior to immunisation and was inversely associated with estimates of age-specific immunisation coverage (65% for 16–18 year olds). The prevalence of HPV 16/18 infection in the post-immunisation survey was 6.5% amongst 16–18 year olds, compared to 19.1% in the similar survey conducted prior to the introduction of HPV immunisation.

Conclusions

These findings are the first indication that the national HPV immunisation programme is successfully preventing HPV 16/18 infection in sexually active young women in England. The reductions seen suggest, for the estimated coverage, high vaccine effectiveness and some herd-protection benefits. Continued surveillance is needed to determine the effects of immunisation on non-vaccine HPV types.

Amino acid sequence diversity of the major human papillomavirus capsid protein: implications for current and next generation vaccines

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We evaluated amino acid diversity of the major capsid protein of HPV.

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Residues displaying high entropy were found within surface-exposed domains.

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We discuss the implications of this diversity on the current and next generation HPV vaccines.

Despite the fidelity of host cell polymerases, the human papillomavirus (HPV) displays a degree of genomic polymorphism resulting in distinct genotypes and intra-type variants. The current HPV vaccines target the most prevalent genotypes associated with cervical cancer (HPV16/18) and genital warts (HPV6/11). Although these vaccines confer some measure of cross-protection, a multivalent HPV vaccine is in the pipeline that aims to broaden vaccine protection against other cervical cancer-associated genotypes including HPV31, HPV33, HPV45, HPV52 and HPV58. Both current and next generation vaccines comprise virus-like particles, based upon the major capsid protein, L1, and vaccine-induced, type-specific protection is likely mediated by neutralizing antibodies targeting L1 surface-exposed domains.

The aim of this study was to perform an in silico analysis of existing full length L1 sequences representing vaccine-relevant HPV genotypes in order to address the degree of naturally-occurring, intra-type polymorphisms. In total, 1281 sequences from the Americas, Africa, Asia and Europe were assembled. Intra-type entropy was low and/or limited to non-surface-exposed residues for HPV6, HPV11 and HPV52 suggesting a minimal effect on vaccine antibodies for these genotypes. For HPV16, intra-type entropy was high but the present analysis did not reveal any significant polymorphisms not previously identified. For HPV31, HPV33, HPV58, however, intra-type entropy was high, mostly mapped to surface-exposed domains and in some cases within known neutralizing antibody epitopes. For HPV18 and HPV45 there were too few sequences for a definitive analysis, but HPV45 displayed some degree of surface-exposed residue diversity. In most cases, the reference sequence for each genotype represented a minority variant and the consensus L1 sequences for HPV18, HPV31, HPV45 and HPV58 did not reflect the L1 sequence of the currently available HPV pseudoviruses. These data highlight a number of variant amino acid residues that warrant further investigation for vaccine and natural history studies of HPV.

A randomized, observer-blinded immunogenicity trial of Cervarix(®) and Gardasil(®) Human Papillomavirus vaccines in 12-15 year old girls

Background

The current generation of Human Papillomavirus (HPV) vaccines, Cervarix® and Gardasil®, exhibit a high degree of efficacy in clinical trials against the two high-risk (HR) genotypes represented in the vaccines (HPV16 and HPV18). High levels of neutralizing antibodies are elicited against the vaccine types, consistent with preclinical data showing that neutralizing antibodies can mediate type-specific protection in the absence of other immune effectors. The vaccines also confer protection against some closely related non-vaccine HR HPV types, although the vaccines appear to differ in their degree of cross-protection. The mechanism of vaccine-induced cross-protection is unknown. This study sought to compare the breadth and magnitudes of neutralizing antibodies against non-vaccine types elicited by both vaccines and establish whether such antibodies could be detected in the genital secretions of vaccinated individuals.

Methods and Findings

Serum and genital samples were collected from 12–15 year old girls following vaccination with either Cervarix® (n = 96) or Gardasil® (n = 102) HPV vaccine. Serum-neutralizing antibody responses against non-vaccine HPV types were broader and of higher magnitude in the Cervarix®, compared to the Gardasil®, vaccinated individuals. Levels of neutralizing and binding antibodies in genital secretions were closely associated with those found in the serum (r = 0.869), with Cervarix® having a median 2.5 (inter-quartile range, 1.7–3.5) fold higher geometric mean HPV-specific IgG ratio in serum and genital samples than Gardasil® (p = 0.0047). There was a strong positive association between cross-neutralizing antibody seropositivity and available HPV vaccine trial efficacy data against non-vaccine types.

Conclusions

These data demonstrate for the first time that cross-neutralizing antibodies can be detected at the genital site of infection and support the possibility that cross-neutralizing antibodies play a role in the cross-protection against HPV infection and disease that has been reported for the current HPV vaccines.

Trial Registration

ClinicalTrials.gov NCT00956553

Frequency and risk factors for prevalent, incident, and persistent genital carcinogenic human papillomavirus infection in sexually active women: community based cohort study

OBJECTIVE

To investigate frequency and risk factors for prevalent, incident, and persistent carcinogenic human papillomavirus (HPV) in young women before the introduction of immunisation against HPV types 16 and 18 for schoolgirls.

DESIGN

Cohort study

SETTING

20 London universities and further education colleges.

PARTICIPANTS

2185 sexually active female students, mean age 21 years (range 16-27), 38% from ethnic minorities, who took part in the POPI (prevention of pelvic infection) chlamydia screening trial in 2004-08 and who provided duplicate, self taken vaginal swabs and completed questionnaires at baseline. At follow-up, a median of 16 months later, 821 women (38%) returned repeat vaginal swabs by post. In 2009-10, stored samples were tested for HPV.

RESULTS

Samples from 404/2185 (18.5% (95% CI 16.9% to 20.2%)) of the cohort were positive for carcinogenic HPV at baseline, including 15.0% (327) positive for non-vaccine carcinogenic genotypes. Reporting two or more sexual partners in the previous year and concurrent Chlamydia trachomatis or bacterial vaginosis were independent risk factors for prevalent vaginal HPV infection. Infection with one or more new HPV types was found in 17.7% (145/821) of follow-up samples, giving an estimated annual incidence of carcinogenic HPV infection of 12.9% (95% CI 11.0% to 15.0%). Incident infection was more common in women reporting two or more partners in the previous year, aged<20, of black ethnicity, or with C trachomatis vaginosis at baseline. Multiple partners was the only independent risk factor for incident infection (adjusted relative risk 1.99 (95% CI 1.46 to 2.72)). Of 143 women with baseline carcinogenic HPV infection, 20 (14% (8.3% to 19.7%) had infection with the same carcinogenic HPV type(s) detected after 12-28 months. Of these women, 13 (65%) had redetected infection with HPV 16 or 18, and nine (45%) with non-vaccine carcinogenic HPV genotypes.

CONCLUSION

In the first UK cohort study of carcinogenic HPV in young women in the community, multiple sexual partners was an independent predictor of both prevalent and incident infection. Infection with non-vaccine carcinogenic genotypes was common. Although current HPV vaccines offer partial cross protection against some non-vaccine carcinogenic HPV types, immunised women will still need cervical screening.

Testing for sexually transmitted infections in a population-based sexual health survey: development of an acceptable ethical approach

Population-based research is enhanced by biological measures, but biological sampling raises complex ethical issues. The third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3) will estimate the population prevalence of five sexually transmitted infections (STIs) (Chlamydia trachomatis, Neisseria gonorrhoeae, human papillomavirus (HPV), HIV and Mycoplasma genitalium) in a probability sample aged 16-44 years. The present work describes the development of an ethical approach to urine testing for STIs, including the process of reaching consensus on whether to return results. The following issues were considered: (1) testing for some STIs that are treatable and for which appropriate settings to obtain free testing and advice are widely available (Natsal-3 provides all respondents with STI and healthcare access information), (2) limits on test accuracy and timeliness imposed by survey conditions and sample type, (3) testing for some STIs with unknown clinical and public health implications, (4) how a uniform approach is easier to explain and understand, (5) practical difficulties in returning results and cost efficiency, such as enabling wider STI testing by not returning results. The agreed approach, to perform voluntary anonymous testing with specific consent for five STIs without returning results, was approved by stakeholders and a research ethics committee. Overall, this was acceptable to respondents in developmental piloting; 61% (68 of 111) of respondents agreed to provide a sample. The experiences reported here may inform the ethical decision making of researchers, research ethics committees and funders considering population-based biological sampling.

Prevalence of human papillomavirus (HPV) infections in sexually active adolescents and young women in England, prior to widespread HPV immunisation

INTRODUCTION

The introduction of an HPV immunisation programme in England should result in a significant reduction in the prevalence of vaccine type infections in young women. Here we describe type-specific HPV prevalence in three samples of the young female population in England, prior to the beginning of mass immunisation in 2008.

METHODS

Residual vulva-vaginal swab samples from females aged under 25 years undergoing chlamydia testing as part of the National Chlamydia Screening Programme (NCSP) or Prevention of Pelvic Infection (POPI) trial were collected from sites across England, together with available demographic and sexual behaviour data. Residual samples were screened for HPV infection using the Hybrid Capture 2 (hc2) HPV DNA Test, including the high-risk (HR) and low-risk (LR) probes. Hc2 positive samples were genotyped using the Roche Linear Array (LA) HPV Genotyping Test.

RESULTS

A total of 3829 samples were included: 2369 from 16 to 24 year old NCSP participants, 275 from 13 to 15 year old NCSP participants and 1185 from 16 to 24 year old POPI participants. Variations in HPV prevalence between and within the different samples followed a pattern largely consistent with differences in sexual behaviour. The prevalence of total HR HPV infection, of HPV 16 and/or 18 (16/18) infection and of five HR HPV types closely related to HPV 16/18 (HPV 31, 33, 45, 52 or 58) amongst 16-24 year old NCSP participants was 35% (95% CI 33-37%), 18% (95% CI 16-19%), and 16% (95% CI 14-18%), respectively. Risk of HR HPV infection increased with age during the teen years and was higher in women who reported two or more sexual partners in the last year and in women with chlamydia infection. Approximately half of women with HPV 16/18 infection also had another non-vaccine HR HPV type present.

CONCLUSIONS

Prior to HPV immunisation, there was a high prevalence of HPV infections in the lower genital tract of young, sexually active females in England. The overall, type-specific, and multiple infection prevalence closely reflected age and sexual activity. These data provide a baseline against which the early impact of HPV immunisation on the prevalence of HPV 16/18 and closely related types in young women can be measured, in order to inform immunisation and cervical screening policies.

Systemic and mucosal immune responses to sublingual or intramuscular human papilloma virus antigens in healthy female volunteers

The sublingual route has been proposed as a needle-free option to induce systemic and mucosal immune protection against viral infections. In a translational study of systemic and mucosal humoral immune responses to sublingual or systemically administered viral antigens, eighteen healthy female volunteers aged 19-31 years received three immunizations with a quadravalent Human Papilloma Virus vaccine at 0, 4 and 16 weeks as sublingual drops (SL, n = 12) or intramuscular injection (IM, n = 6). IM antigen delivery induced or boosted HPV-specific serum IgG and pseudovirus-neutralizing antibodies, HPV-specific cervical and vaginal IgG, and elicited circulating IgG and IgA antibody secreting cells. SL antigens induced ~38-fold lower serum and ~2-fold lower cervical/vaginal IgG than IM delivery, and induced or boosted serum virus neutralizing antibody in only 3/12 subjects. Neither route reproducibly induced HPV-specific mucosal IgA. Alternative delivery systems and adjuvants will be required to enhance and evaluate immune responses following sublingual immunization in humans.

TRIAL REGISTRATION

ClinicalTrials.govNCT00949572.

Human papillomavirus genotype detection and viral load in paired genital and urine samples from both females and males

The ability to detect type-specific high risk HPV (HR-HPV) infections in samples from females and males is important for monitoring the epidemiology of HPV and the impact of vaccination. Type-specific detection concordance between paired urine and genital samples from females (n = 264) undergoing routine colposcopy and males (n = 88) attending a genito-urinary medicine clinic was evaluated using an in-house genotyping assay. The overall inter-rater agreement (κ) was 0.781 for female pairs and 0.346 for male pairs. Female urine had sensitivity for detection of HPV16/18 and HR-HPV of 75% and 84%, respectively, while male urine had sensitivities of 13% and 28%, respectively. Genital samples had a higher HPV DNA copy number than urine although a small proportion (10%) of urine samples had a higher copy number than the corresponding genital sample. The proportion of females with normal cytology positive for HPV16/18 was 19%, increasing to 57% in moderate or severely dyskaryotic samples. The same trend was seen in the corresponding urine (19-43%) compounded by the reduced sensitivity of this sample type. The HPV16 viral load in female genital samples, but not in urine, was weakly associated with cervical disease stage. Despite reduced sensitivity, urine appears to be an appropriate surrogate sample for type-specific HPV detection in females for epidemiological objectives. The lower sensitivity and lack of association between viral load and disease stage in urine suggest that urine may not be useful for clinical management of HPV infection. The utility of urine for type-specific detection in males is less certain.

Epidemiology of, and behavioural risk factors for, sexually transmitted human papillomavirus infection in men and women in Britain

OBJECTIVES

Persistent infection with high-risk sexually transmitted human papillomaviruses (HR-HPVs) can lead to development of cervical and other cancers, while low-risk types (low-risk HPV) may cause genital warts. We explored the epidemiology of different HPV types in men and women and their association with demographic and behavioural variables.

METHODS

We analysed data collected for the British National Survey of Sexual Attitudes and Lifestyles, a cross-sectional survey undertaken in 1999-2001. Half of all sexually experienced male and female respondents aged 18-44 years were invited to provide a urine sample. We tested 3123 stored urine samples using an in-house Luminex-based HPV genotyping system.

RESULTS

HPV DNA was detected in 29.0% (95% CI 26.7% to 31.3%) of samples from women and 17.4% (95% CI 15.1% to 19.8%) from men. Any of 13 HR-HPV types was detected in 15.9% (95% CI 14.1% to 17.8%) of women and 9.6% (95% CI 8.0% to 11.6%) of men. HPV types 16/18 were found in 5.5% (95% CI 4.5% to 6.8%) of women and 3.0% (95% CI 2.1% to 4.3%) of men; and types 6/11 in 4.7% (95% CI 1.8% to 5.9%) of women and 2.2% (95% CI 1.5% to 3.1%) of men. In multivariate analysis, HR-HPV was associated with new partner numbers, in women with younger age, single status and partner concurrency, and in men with number of partners without using condom(s) and age at first intercourse.

CONCLUSIONS

HPV DNA was detectable in urine of a high proportion of the sexually active British population. In both genders, HR-HPV was strongly associated with risky sexual behaviour. The minority of HPV infections were of vaccine types. It is important to monitor HPV prevalence and type distribution following the introduction of vaccination of girls.