Evaluation of safety and immunogenicity of a quadrivalent human papillomavirus vaccine in healthy females between 9 and 26 years of age in Sub-Saharan Africa

Understanding human papillomavirus vaccine response and efficacy in people living with HIV: A systematic mixed studies review and meta-analysis

Coinfection with human papillomavirus (HPV) and HIV compounds the risks of developing cervical, anal, and HPV-associated oral neoplasia. Safe prophylactic vaccines are available to prevent HPV infections in people with HIV(PWH). Yet, vaccine efficacy and duration of protection remain questionable. Historically, the efficacy of vaccines has been suboptimal in PWH compared to people without HIV (PWoH).A systematic review of HPV vaccine trials in PWH was conducted using PRISMA guidelines. Outcomes of interest were vaccine efficacy, immunogenicity, and predictors of HPV vaccine efficacy. A secondary outcome was to assess age and sex differences. Efficacy was reviewed as cervical/anal/oral lesions or neoplasia, and incident or persistent HPV infection following vaccination. A random effects meta-analysis was performed comparing geometric mean titer (GMT) in PWH to PWoH. Twenty-eight studies out of 988 were eligible for inclusion in our study, and qualitatively synthesized. Eight of these studies were meta-analyzed. GMT results of HPV16 and HPV18 genotypes were significantly lower in PWH; Hedges's g -0.434 (95% CI: -0.823, -0.046) and Hedges's g -0.57 (95% CI: -0.72, -0.43), respectively. The mean difference in GMT for HPV18 between PWH and PWoH was -536.23 (95% CI: -830.66, -241.81); approximately 22 times higher than HPV18 seropositivity cut-offs, assuming milli-Merck Units per milliliter. Risk factors for incident or persistent infections in PWH included: failure to seroconvert after vaccination, baseline CD4+ T-cell count <500 cells/mm3, early age of sexual debut, HIV viral load ≥ 400 copies/mL. There was a trend towards decreased HPV vaccine efficacy in studies that included enrollees with a history of AIDS or AIDS-defining illness.Applying existing evidence of HPV vaccine efficacy on meaningful clinical outcomes in PWH is questionable. This could be influenced by the diversity of eligibility criteria across clinical trials of HPV vaccine efficacy. Precision medicine may offer novel alternatives for evaluating HPV vaccine efficacy in PWH.

Immunogenicity and safety of quadrivalent and 9-valent human papillomavirus vaccines in Indian clinical trial participants

The quadrivalent human papillomavirus (qHPV; HPV6/11/16/18) and 9-valent HPV (9vHPV; HPV6/11/16/18/31/33/45/52/58) vaccines have demonstrated efficacy, immunogenicity, and safety in international clinical trials. We report outcomes from three completed clinical trials in India: a single-arm study (V501-029 [NCT00380367]) in Indian girls (aged 9-15 years; N = 110) evaluating qHPV vaccine immunogenicity and safety; a subgroup analysis (n = 225) of Indian girls/boys (9-15 years) and women (16-26 years) from a global study (V503-002 [NCT00943722]) evaluating 9vHPV vaccine immunogenicity and safety; and a qHPV vaccine post-marketing safety surveillance study (V501-125) in Indian females (aged 9-45 years; N = 188) vaccinated during routine care. In V501-029 and V503-002, HPV vaccines were administered as 3 doses (Day 1, Month 2, Month 6). Serum HPV antibodies were evaluated by competitive Luminex immunoassays at Day 1 and Month 7 (both studies) and Months 12, 24, and 36 (V503-002 only). Adverse events (AEs) were collected by Vaccination Report Card. In V501-125, participants were actively surveilled for serious AEs (SAEs) within 30 days post-qHPV vaccination. In per-protocol analyses, qHPV and 9vHPV vaccines induced robust anti-HPV6/11/16/18 (V501-029) and HPV6/11/16/18/31/33/45/52/58 (V503-002) responses, respectively; ≥97% of participants seroconverted at Month 7 for each vaccine HPV type in both studies, and antibody responses persisted through 36 months in V503-002. The most common AEs were injection-site-associated. Most AEs were mild/moderate; no deaths, vaccine-related SAEs, or discontinuations due to AEs were reported. In V501-125, no SAE was reported. Overall, the qHPV and 9vHPV vaccines elicited robust antibody responses and were generally well tolerated in Indian participants.

Optimization of a protocol for the evaluation of antibody responses to human papillomavirus (HPV) vaccination in low-resource settings

Introduction

Available human papillomavirus (HPV) vaccines could have an important primary role in cervical cancer prevention once their long-term immunogenicity and safety are evaluated at the population level. The aim of this study was to optimize an assay to be used in evaluating the long-term durability of HPV vaccine response following a pilot vaccination of adolescent girls in Ghana.

Methods

A rapid, high-throughput, indirect enzyme-linked immunosorbent assay (ELISA) was optimized for the detection and quantitation of anti-HPV L1 (late expression protein: types 6, 11, 16 and 18) immunoglobulin G (IgG) in human serum (n = 89). The utility of the assay was demonstrated using serum collected from a cohort of pre-adolescent girls (n = 49) previously vaccinated with a quadrivalent vaccine and non-immune serum obtained from age-matched controls (n = 40).

Results

The assay showed good discrimination of antibody levels between cases and control sera: seroprevalence of anti-HPV IgG antibodies was significantly higher among vaccinated than unvaccinated girls for both HPV-16 (63.3% vs. 12.5%; p < 0.001) and HPV-18 (34.7% vs. 20.0%; p = 0.042), respectively. Thirty-six months after receiving the third dose of vaccine, significantly higher mean anti-HPV-16 (0.618 vs. 0.145), anti-HPV-18 (0.323 vs. 0.309), and anti-HPV-6 (1.371 vs. 0.981) antibody levels were measured, compared to unvaccinated girls (all p < 0.05). A correlation between optical density and antibody activity indicated assay sensitivity to increasing levels of antibody activity.

Conclusion

We have successfully optimized and implemented a robust and sensitive assay for the evaluation of antibody responses among immunized adolescent girls for monitoring future large-scale HPV vaccination studies in low-income settings. Our results demonstrated greater immunoglobulin G antibody activity within serum drawn from adolescent girls immunized 36 months prior.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-022-01821-y.

Adolescent Health Series: HPV infection and vaccination in sub-Saharan Africa: 10 years of research in Tanzanian female adolescents - narrative review

Cervical cancer is the leading cause of cancer-related morbidity and mortality in many sub-Saharan African (SSA) countries, including Tanzania. Most cervical cancer cases worldwide are attributable to infection of the cervix with Human Papillomavirus (HPV), a vaccine-preventable sexually transmitted infection (STI). Over the past 10 years, we have conducted a programme of HPV research in pre-adolescents and adolescents in Mwanza, the second-largest city in Tanzania, which is situated in a malaria-endemic region. In this narrative review article, we summarise the contribution of our work, alongside work of others, to improve the understanding of HPV epidemiology in SSA and development of setting-appropriate, evidence-based intervention strategies. We present evidence for very high prevalence and incidence of HPV infection among female SSA adolescents around the time of sexual debut, describe risk factors for HPV acquisition, and discuss associations between HPV, HIV and other STIs, which are also highly prevalent within this population. We summarise findings from early clinical trials of HPV vaccines in SSA, the first of which was an immunogenicity and safety trial conducted in Mwanza, Tanzania, and Dakar, Senegal. Within the trial, we evaluated for the first time the potential impact of malaria and helminth infection on vaccine-induced antibody responses in Tanzanian girls. We describe research evaluating optimal HPV vaccine delivery strategies within this setting, perceived requirements for and barriers to vaccine implementation among key informants from LMIC, vaccine acceptability among girls and parents, and opportunities for co-delivery of interventions alongside HPV vaccination to an adolescent population. Finally, we discuss country-level barriers to vaccine uptake in LMIC, and ongoing studies in Tanzania and other SSA countries of reduced-dose HPV vaccination schedules that may alleviate cost and logistical barriers to vaccine implementation.

Update on Safety and Efficacy of HPV Vaccines: Focus on Gardasil

The human papillomavirus (HPV) is a highly contagious and prevalent virus that is primarily sexually transmitted. The Gardasil® quadrivalent vaccine, the Cevarix® bivalent vaccine and the Gardasil® 9 nonavalent vaccine were developed to prevent the spread of HPV as well as the incidence of its associated diseases. The aim of this mini-review is to critically analyze the safety and efficacy of both the Gardasil vaccines. A literature search was conducted on ProQuest, MedLine, Science Direct and Scopus databases. More than hundred articles were scanned, and from this, 38 most relevant papers involving human studies across several countries were closely reviewed. The literature deems the Gardasil® HPV vaccines to be safe and efficacious. Due to the novel nature of these vaccines, long-term efficacies, as well as their associated long-term adverse effects, are yet to be confirmed. Of some concern was the finding that a majority of these studies disclosed minor to major involvement with the vaccine manufacturers, and the inhibitory cost of use in developing nations. Gardasil is largely considered safe to use. However, considering that these vaccines are predominantly indicated for children, further comprehensive, impartial, and long-term studies are needed to critically assess safety and efficacy.

The comparative safety of human papillomavirus vaccines: A Bayesian network meta-analysis

BACKGROUND AND AIMS

The safety of human papillomavirus (HPV) vaccines, one of the major challenges to public vaccination, has been controversial. This study assessed the adverse reactions of various HPV vaccines, including bivalent HPV (2vHPV), quadrivalent HPV (4vHPV), and 9-valent HPV (9vHPV) vaccines.

METHODS

PubMed, Embase, and Central databases were searched for randomized controlled trials (RCTs) on the comparative safety of HPV vaccines. A network meta-analysis was performed based on the Bayesian framework random-effects model.

RESULTS

This study included 23 RCTs. Analysis across these reports indicated that the 2vHPV vaccine was associated with significantly more systemic adverse events than the 4vHPV vaccine (risk ratio [RR]: 1.28, 95% credible interval [CrI]: 1.14-1.44), 9vHPV vaccine (RR: 1.25, 95% CrI: 1.06-1.49), and placebo (RR: 1.31, 95% CrI: 1.18-1.46). However, there were no statistically significant differences in serious adverse events between the vaccinated and placebo groups. For injection-site adverse events, there were substantial inconsistencies between the direct and indirect effects; therefore, the analysis results of the safety were presented only for systemic and serious adverse events.

CONCLUSIONS

The 2vHPV vaccine resulted in more systemic adverse events than other vaccines and placebo. No significant differences in serious adverse events were observed. Further studies are needed to obtain more information regarding the safety of HPV vaccines.

Sex difference in the immunogenicity of the quadrivalent Human Papilloma Virus vaccine: Systematic review and meta-analysis

BACKGROUND

Immunological differences between males and females in response to viral vaccines are well known. This the first review to examine them for the Human Papilloma Virus.

METHODS

We conducted a systematic review and meta-analysis of the immunogenicity of the Quadrivalent Human Papilloma Virus Vaccine qHPVV. We searched Medline, Embase, and CENTRAL for trials published until September 17, 2019. Inclusion criteria were 3-doses and reporting geometric mean titers (GMTs). We performed random-effects meta-analyses and meta-regression separated by age group and sex.

RESULTS

Our search yielded 1809 unique studies. 334 full texts were screened and data from 18 studies were extracted. Females had higher pooled geometric mean titers than males in all age groups. Log transformed GMTs in male children (<16) years were: against HPV6: 6·62 (95% CI 6·29-6·94; I² = 86·0%), against HPV11: 7·07 (95% CI 6·90-7·23; I² = 63.1%), against HPV16: 8·53 (95% CI 8·28-8·78; I² = 73·0%), and against HPV18 7·21 (95% CI 7·08-7·34; I² = 26·4%). In females: against HPV6 7·10 (95% CI 6·79-7·41; I² = 96·6%), HPV11: 7·32 (95% CI 7·15-7·50; I² = 90·6%), HPV16: 8·71 (95% CI 8·52-8·91; I² = 90·2%), and HPV18 7·35 (95% CI 7·11-7·58; I² = 92·7%). In the meta-regression, the sexual difference was significant for HPV6 (p = 0·022) with a similar tendency for HPV11 (p = 0·066) and HPV18 (p = 0·079). Immunogenicity was significantly higher in children (<16) than in adults (p < 0·001).

CONCLUSION

Females have higher antibody titers against HPV after receiving the qHPVV than do males. The difference is bigger in low-risk HPV strains. Adjusting the doses and schedules for each sex should be explored further.

Natural and vaccine-induced B cell-derived systemic and mucosal humoral immunity to human papillomavirus

Introduction: Human papillomavirus (HPV) are the causative agent of mucosal neoplasia. Both cervical, anal and oropharyngeal cancers incidence is constantly increasing, making the HPV infection, a significant worldwide concern. Together, the CD8+ T cytotoxic cell-mediated response and the HPV-specific antibody response control most of the HPV infections before the development of cancers.Areas covered: We searched the MEDLINE and EMBASE databases and identified 228 eligible studies from 1987 to 2019 which examines both naturally acquired and vaccine induced humoral immunity against HPV infection in female and male subjects from worldwide origin. Herein, we synthesize current knowledge on the features of systemic and mucosal humoral immunity against HPV. We discuss the issues of the balance between the viral clearance or the escape to the host immune response, the differences between natural and vaccine-induced HPV-specific antibodies and their neutralizing capability. We also discuss the protection afforded after natural infection or following prophylactic vaccination.Expert opinion: Understanding the antibody response induced by HPV infection has led to the design of first-generation prophylactic vaccines. Now, prophylactic vaccination induces protective and long-lasting antibody response which would also strengthened the natural moderate humoral response in people previously exposed to the virus.

The effectiveness of vaccination to prevent the papillomavirus infection: a systematic review and meta-analysis

Our purpose was to determine the effectiveness and harms of vaccination in patients with any sexual history to prevent the prevalence of papillomavirus infection. A search strategy was conducted in the MEDLINE, CENTRAL, EMBASE and LILACS databases. Searches were also conducted in other databases and unpublished literature. The risk of bias was evaluated with the Cochrane Collaboration's tool. Analysis of fixed effects was conducted. The primary outcome was the infection by any and each human papillomavirus (HPV) genotype, serious adverse effects and short-term adverse effects. The measure of the effect was the risk difference (RD) with a 95% confidence interval (CI). The planned interventions were bivalent vaccine/tetravalent/nonavalent vs. placebo/no intervention/other vaccines. We included 29 studies described in 35 publications. Bivalent HPV vaccine offers protection against HPV16 (RD −0.05, 95% CI −0.098 to −0.0032), HPV18 (RD −0.03, 95% CI −0.062 to −0.0004) and HPV16/18 genotypes (RD of −0.1, 95% CI −0.16 to −0.04). On the other side, tetravalent HPV vaccine offered protection against HPV6 (RD of −0.0500, 95% CI −0.0963 to −0.0230), HPV11 (RD −0.0198, 95% CI −0.0310 to −0.0085). Also, against HPV16 (RD of −0.0608, 95% CI −0.1126 to −0.0091) and HPV18 (RD of −0.0200, 95% CI −0.0408 to −0.0123). There was a reduction in the prevalence of HPV16, 18 and 16/18 genotypes when applying the bivalent vaccine, with no increase in adverse effects. Regarding the tetravalent vaccine, we found a reduction in the prevalence of HPV6, 11, 16 and 18 genotypes, with no increase in adverse effects.

[HPV vaccination: not only female adolescents and not only prophylactic. Review and position paper of the Italian HPV Study Group (IHSG)]

HPV vaccination has been introduced in clinical practice in recent years and represents the most effective strategy of primary prevention of cervical carcinoma and of female genital preneoplastic conditions. One of the major issues of the subject is represented by vaccination coverage of the target population. Since its introduction, HPV vaccine efficacy has been progressively demonstrated also towards extragenital HPV-correlated conditions and in males too. Moreover, even subjects of older age groups or subjects who already had HPV infections have been demonstrated to received benefits from vaccination, due to improvements of their immunological response. Recently, vaccine efficacy has also been investigated in terms of adjuvant administration after treatments of preneoplastic or benign conditions of the female lower genital tract caused by HPVs; preliminary results indicate an interesting and promising field of application. On this basis, in this article an analysis of the state of the art has been performed, with specific regard to the Italian scenario and with the focus of future perspectives of implementation of the HPV vaccination policy. From the available evidences, the Italian HPV Study Group recommends the extension of systematic HPV vaccination to males too, to adult subjects and also after conservative treatment of genital HPV correlated conditions.

Efficacy and safety of prophylactic HPV vaccines. A Cochrane review of randomized trials

INTRODUCTION

Recently, the evidence on efficacy and safety of prophylactic HPV vaccines derived from randomized trials was published in the Cochrane database of Systematic reviews. A summary of this Cochrane review is presented below.

AREAS COVERED

Only trials involving mono-, bi-, and quadrivalent HPV vaccines were included. Trials evaluating the nonavalent vaccine were excluded since women in the control group received the quadrivalent vaccine. Main efficacy outcomes were: histologically confirmed cervical precancer lesions distinguishing those associated with vaccine HPV types and any cervical precancer. Exposure groups were: women aged: 15-26 or 24-45 years being initially negative for high-risk HPV (hrHPV) or negative for the vaccine types and women unselected by HPV status.

EXPERT COMMENTARY

All evaluated vaccines offered excellent protection against cervical intraepithelial neoplasia of grade 2 or 3 (CIN2 or CIN3) and adenocarcinoma in situ associated with HPV16/18 infection in young women who were not initially infected with hrHPV or HPV16/18. Vaccine efficacy was lower when all women regardless of HPV DNA status at enrollment were included. In young women, HPV vaccination protected also against any cervical precancer but the magnitude of protection was lower than against HPV16/18 associated cervical precancer. Vaccine efficacy was lower in mid-adult (aged 24-45 years) women. No protection against cervical precancer was found in mid-adult women unselected by HPV DNA status at enrollment. Trials were not empowered to address protection against cervical cancer. Occurrence of severe adverse events or adverse pregnancy outcomes was not significantly higher in recipients of HPV vaccines than in women included in the control arms.

Quadrivalent HPV vaccine in HIV-1-infected early adolescent girls and boys in Kenya: Month 7 and 12 post vaccine immunogenicity and correlation with immune status

INTRODUCTION

In sub-Saharan Africa, a generation of HIV-1-infected children is approaching the age of sexual debut and becoming at risk for HPV infection and its sequelae. We assessed safety and immunogenicity of the quadrivalent HPV (qHPV) vaccine in HIV-1-infected adolescents.

METHODS

In an open-label trial among Kenyan, HIV-1-infected adolescents aged 9-14 years, we administered the qHPV vaccine at 0, 2 and 6 months and measured antibody titers to HPV-16, 18, 6 and 11 at month 7 and 12 post-vaccination. Measures of immunogenic response from HIV-1-negative historical cohorts from Africa and HIV-1 positive adolescent cohorts from the USA were used for comparison.

RESULTS

We enrolled 100 girls and 80 boys with a median age of 12 years and median baseline CD4 cell count of 684 (IQR 478, 935) cells/µL. One hundred and fifty four (86%) were receiving antiretroviral therapy for a median of 4.5 (IQR 2.3, 6.3) years; 110 (71%) had <400 copies of plasma HIV-1 RNA/mL. Of 189 enrolled children, 179 received all three doses. Two hundred and eighty five (64%) of 445 adverse events were injection site reactions; none were greater than grade 2. Of 6 Serious Adverse Events (SAEs), none were considered vaccine related. Seroconversion to HPV-18, 16, 11, 6 at month 7 occurred in 93.3%, 98.3%, 97.2% and 99.6% of vaccine recipients; similar rates have been reported in historical controls. The mean log₁₀ HPV antibody titer measured at month 7 increased with each log₁₀ increase in CD4 by 1.4 (95% CI: 1.1-1.7) for HPV-18; 1.2 (0.9-1.4) for HPV-16; 1.1 (0.8-1.3) for HPV-11; 0.7 (0.5-1.0) for HPV-6 (all p < 0.0001).

CONCLUSION

Almost all Kenyan HIV-1-infected adolescents mounted an immune response comparable to other immunized populations. HPV antibody titers were higher in those with preserved CD4 cell counts. Longer term-follow up will determine sustainability of the immune response. ClinicalTrials.gov number, NCT00557245.

Safety of Human Papillomavirus Vaccines: An Updated Review

Human papillomavirus (HPV) vaccines are now included in immunisation programmes in 71 countries. Unfortunately, uptake has been impacted in some countries by reduced confidence in the safety of the HPV vaccine. In 2013, we published an extensive review demonstrating a reassuring safety profile for bivalent (2vHPV) and quadrivalent (4vHPV) vaccines. A nonavalent (9vHPV) vaccine is now available and HPV immunisation programmes have been extended to males in 11 countries. The aim of this updated narrative review was to examine the evidence on HPV vaccine safety, focusing on the 9vHPV vaccine, special populations and adverse events of special interest (AESI). The previous searches were replicated to identify studies to August 2016, including additional search terms for AESI. We identified 109 studies, including 15 population-based studies in over 2.5 million vaccinated individuals across six countries. All vaccines demonstrated an acceptable safety profile; injection-site reactions were slightly more common for 9vHPV vaccine than for 4vHPV vaccine. There was no consistent evidence of an increased risk of any AESI, including demyelinating syndromes or neurological conditions such as complex regional pain or postural orthostatic tachycardia syndromes. The risk-benefit profile for HPV vaccines remains highly favourable.

Prophylactic vaccination against human papillomaviruses to prevent cervical cancer and its precursors

BACKGROUND

Persistent infection with high-risk human papillomaviruses (hrHPV) types is causally linked with the development of cervical precancer and cancer. HPV types 16 and 18 cause approximately 70% of cervical cancers worldwide.

OBJECTIVES

To evaluate the harms and protection of prophylactic human papillomaviruses (HPV) vaccines against cervical precancer and HPV16/18 infection in adolescent girls and women.

SEARCH METHODS

We searched MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL) and Embase (June 2017) for reports on effects from trials. We searched trial registries and company results' registers to identify unpublished data for mortality and serious adverse events.

SELECTION CRITERIA

Randomised controlled trials comparing efficacy and safety in females offered HPV vaccines with placebo (vaccine adjuvants or another control vaccine).

DATA COLLECTION AND ANALYSIS

We used Cochrane methodology and GRADE to rate the certainty of evidence for protection against cervical precancer (cervical intraepithelial neoplasia grade 2 and above [CIN2+], CIN grade 3 and above [CIN3+], and adenocarcinoma-in-situ [AIS]), and for harms. We distinguished between the effects of vaccines by participants' baseline HPV DNA status. The outcomes were precancer associated with vaccine HPV types and precancer irrespective of HPV type. Results are presented as risks in control and vaccination groups and risk ratios (RR) with 95% confidence intervals in brackets.

MAIN RESULTS

We included 26 trials (73,428 participants). Ten trials, with follow-up of 1.3 to 8 years, addressed protection against CIN/AIS. Vaccine safety was evaluated over a period of 6 months to 7 years in 23 studies. Studies were not large enough or of sufficient duration to evaluate cervical cancer outcomes. All but one of the trials was funded by the vaccine manufacturers. We judged most included trials to be at low risk of bias. Studies involved monovalent (N = 1), bivalent (N = 18), and quadrivalent vaccines (N = 7). Most women were under 26 years of age. Three trials recruited women aged 25 and over. We summarize the effects of vaccines in participants who had at least one immunisation.Efficacy endpoints by initial HPV DNA statushrHPV negativeHPV vaccines reduce CIN2+, CIN3+, AIS associated with HPV16/18 compared with placebo in adolescent girls and women aged 15 to 26. There is high-certainty evidence that vaccines lower CIN2+ from 164 to 2/10,000 (RR 0.01 (0 to 0.05)) and CIN3+ from 70 to 0/10,000 (RR 0.01 (0.00 to 0.10). There is moderate-certainty evidence that vaccines reduce the risk of AIS from 9 to 0/10,000 (RR 0.10 (0.01 to 0.82).HPV vaccines reduce the risk of any CIN2+ from 287 to 106/10,000 (RR 0.37 (0.25 to 0.55), high certainty) and probably reduce any AIS lesions from 10 to 0/10,000 (RR 0.1 (0.01 to 0.76), moderate certainty). The size of reduction in CIN3+ with vaccines differed between bivalent and quadrivalent vaccines (bivalent: RR 0.08 (0.03 to 0.23), high certainty; quadrivalent: RR 0.54 (0.36 to 0.82), moderate certainty). Data in older women were not available for this comparison.HPV16/18 negativeIn those aged 15 to 26 years, vaccines reduce CIN2+ associated with HPV16/18 from 113 to 6 /10,000 (RR 0.05 (0.03 to 0.10). In women 24 years or older the absolute and relative reduction in the risk of these lesions is smaller (from 45 to 14/10,000, (RR 0.30 (0.11 to 0.81), moderate certainty). HPV vaccines reduce the risk of CIN3+ and AIS associated with HPV16/18 in younger women (RR 0.05 (0.02 to 0.14), high certainty and RR 0.09 (0.01 to 0.72), moderate certainty, respectively). No trials in older women have measured these outcomes.Vaccines reduce any CIN2+ from 231 to 95/10,000, (RR 0.41 (0.32 to 0.52)) in younger women. No data are reported for more severe lesions.Regardless of HPV DNA statusIn younger women HPV vaccines reduce the risk of CIN2+ associated with HPV16/18 from 341 to 157/10,000 (RR 0.46 (0.37 to 0.57), high certainty). Similar reductions in risk were observed for CIN3+ associated with HPV16/18 (high certainty). The number of women with AIS associated with HPV16/18 is reduced from 14 to 5/10,000 with HPV vaccines (high certainty).HPV vaccines reduce any CIN2+ from 559 to 391/10,000 (RR 0.70 (0.58 to 0.85, high certainty) and any AIS from 17 to 5/10,000 (RR 0.32 (0.15 to 0.67), high certainty). The reduction in any CIN3+ differed by vaccine type (bivalent vaccine: RR 0.55 (0.43 to 0.71) and quadrivalent vaccine: RR 0.81 (0.69 to 0.96)).In women vaccinated at 24 to 45 years of age, there is moderate-certainty evidence that the risks of CIN2+ associated with HPV16/18 and any CIN2+ are similar between vaccinated and unvaccinated women (RR 0.74 (0.52 to 1.05) and RR 1.04 (0.83 to 1.30) respectively). No data are reported in this age group for CIN3+ or AIS.Adverse effectsThe risk of serious adverse events is similar between control and HPV vaccines in women of all ages (669 versus 656/10,000, RR 0.98 (0.92 to 1.05), high certainty). Mortality was 11/10,000 in control groups compared with 14/10,000 (9 to 22) with HPV vaccine (RR 1.29 [0.85 to 1.98]; low certainty). The number of deaths was low overall but there is a higher number of deaths in older women. No pattern in the cause or timing of death has been established.Pregnancy outcomesAmong those who became pregnant during the studies, we did not find an increased risk of miscarriage (1618 versus 1424/10,000, RR 0.88 (0.68 to 1.14), high certainty) or termination (931 versus 838/10,000 RR 0.90 (0.80 to 1.02), high certainty). The effects on congenital abnormalities and stillbirths are uncertain (RR 1.22 (0.88 to 1.69), moderate certainty and (RR 1.12 (0.68 to 1.83), moderate certainty, respectively).

AUTHORS' CONCLUSIONS

There is high-certainty evidence that HPV vaccines protect against cervical precancer in adolescent girls and young women aged 15 to 26. The effect is higher for lesions associated with HPV16/18 than for lesions irrespective of HPV type. The effect is greater in those who are negative for hrHPV or HPV16/18 DNA at enrolment than those unselected for HPV DNA status. There is moderate-certainty evidence that HPV vaccines reduce CIN2+ in older women who are HPV16/18 negative, but not when they are unselected by HPV DNA status.We did not find an increased risk of serious adverse effects. Although the number of deaths is low overall, there were more deaths among women older than 25 years who received the vaccine. The deaths reported in the studies have been judged not to be related to the vaccine. Increased risk of adverse pregnancy outcomes after HPV vaccination cannot be excluded, although the risk of miscarriage and termination are similar between trial arms. Long-term of follow-up is needed to monitor the impact on cervical cancer, occurrence of rare harms and pregnancy outcomes.

Safety of human papillomavirus vaccines in healthy young women: a meta-analysis of 24 controlled studies

BACKGROUND

Human papillomavirus (HPV) vaccines have been shown to be effective for the eradication of HPV and prevention of cervical cancer. However, the number of women who receive HPV vaccinations has decreased over the last several years in Japan, due to concerns about adverse reactions associated with the vaccines. We evaluated the safety of three types of HPV vaccines separately in young women and the difference in the risk of adverse reactions between HPV and other vaccines by conducting a meta-analysis.

METHODS

Primary literature was retrieved from MEDLINE, the Cochrane Central Register of Controlled Trials, and Japana Centra Revuo Medicina. Prospective controlled studies with participants consisting exclusively of healthy women who received bivalent, quadrivalent, or 9-valent HPV (2vHPV, 4vHPV or 9vHPV) vaccines were included. Primary safety outcome was the incidence of solicited local and systemic symptoms, and unsolicited symptoms. When two or more studies were found for the same analysis, a meta-analysis was applied.

RESULTS

A total of 24 controlled studies from 22 articles were included in our study. Of the 24 studies, 16 were placebo-controlled and eight were active-controlled (different HPV vaccine or hepatitis vaccine). Average ages of the participants ranged from 12 to 37 years. A significantly higher incidence of solicited local symptoms was observed following injection of HPV vaccines (2vHPV and 4vHPV) compared to placebo, but there was no difference between HPV vaccines [risk ratio (RR) for 2vHPV: 1.25, 95% confidence interval (CI): 1.09 to 1.43, RR for 4vHPV: 1.16, 95% CI: 1.11 to 1.20]. The incidence of solicited systemic symptoms was not different between HPV vaccines and placebo (RR: 1.04, 95% CI: 0.99 to 1.09). The incidence of unsolicited symptoms was significantly higher for 2vHPV vaccine compared to placebo (RR: 1.28, 95% CI: 1.01 to 1.63), but was not significantly different between 2vHPV and hepatitis B vaccines.

CONCLUSIONS

HPV vaccines had significantly higher risk of any injection site symptom compared to placebo or other vaccines (hepatitis A and B vaccines), and the incidence of solicited local symptoms was no difference between 2vHPV vaccination and 4vHPV vaccination. However, the most adverse reactions were transient.

Impact of baseline covariates on the immunogenicity of the 9-valent HPV vaccine - A combined analysis of five phase III clinical trials

BACKGROUND

The immunogenicity profile of the 9-valent HPV (9vHPV) vaccine was evaluated across five phase III clinical studies conducted in girls and boys 9-15 years of age and young women 16-26 years of age. The effect of baseline characteristics of subjects on vaccine-induced HPV antibody responses was assessed.

METHODS

Immunogenicity data from 11,304 subjects who received ≥1 dose of 9vHPV vaccine in five Phase III studies were analyzed. Vaccine was administered as a 3-dose regimen. HPV antibody titers were assessed 1 month after dose 3 using a competitive Luminex immunoassay and summarized as geometric mean titers (GMTs). Covariates examined were age, gender, race, region of residence, and HPV serostatus and PCR status at day 1.

RESULTS

GMTs to all 9 vaccine HPV types decreased with age at vaccination initiation, and were otherwise generally similar among the demographic subgroups defined by gender, race and region of residence. For all subgroups defined by race or region of residence, GMTs were higher in girls and boys than in young women. Vaccination of subjects who were seropositive at day 1 to a vaccine HPV type resulted in higher GMTs to that type, compared with those in subjects who were seronegative for that type at day 1.

CONCLUSIONS

9vHPV vaccine immunogenicity was robust among subjects with differing baseline characteristics. It was generally comparable across subjects of different races and from different regions. Greater immunogenicity in girls and boys versus young women (the population used to establish 9vHPV vaccine efficacy in clinical studies) indicates that the anti-HPV responses generated by the vaccine in adolescents from all races or regions were sufficient to induce high-level protective efficacy. This immunogenicity profile supports a widespread 9vHPV vaccination program and early vaccination.

Cervical cancer, human papillomavirus and vaccines: assessment of the information retrieved from general knowledge websites in Chile

OBJECTIVES

Cervical cancer is the most common gynaecologic malignancy worldwide and is the sixth cause of cancer death in Chile. Human papillomavirus (HPV) is responsible for most cervical cancers. Individuals seeking basic information about HPV frequently turn to health information websites. We hypothesized that some of their data may be inaccurate.

STUDY DESIGN

Comparative analysis of information.

METHODS

We analyze the content of highly accessed websites such as the Spanish version of Wikipedia and Yahoo Answers through the application of a questionnaire, as well as a website managed by the Chilean Ministry of Health (Minsal). The accuracy of each answer was confirmed by comparison with information retrieved from articles published by indexed journals.

RESULTS

The information provided by the Spanish version of Wikipedia was accurate; nevertheless a few omissions were detected. The quality of the information provided by the Spanish version of Yahoo Answers was inaccurate and confusing. The Minsal website lacked important information on several topics about HPV even though it is managed and endorsed by the government.

CONCLUSIONS

We suggest periodical content reviews to increase the completeness, transparency and correctness of the website.