Comparing one dose of HPV vaccine in girls aged 9-14 years in Tanzania (DoRIS) with one dose of HPV vaccine in historical cohorts: an immunobridging analysis of a randomised controlled trial

Human papillomavirus vaccination at age 9 or 10 years to increase coverage - a narrative review of the literature, United States 2014-2024

The Advisory Committee on Immunization Practices recommends routine human papillomavirus (HPV) vaccination at 11-12 years; the series can begin at age 9. U.S. HPV vaccination coverage is lower than other adolescent vaccinations. One proposed strategy to increase coverage is initiation at 9-10 years. We systematically reviewed studies addressing vaccination at age 9 to identify and evaluate evidence regarding potential programmatic advantages. Among 30 publications from 2014 to 2024 there were retrospective cohort studies (N = 11), intervention studies with a component focused on vaccination at 9-10 (N = 12), and studies of feasibility or acceptability by providers or caregivers (N = 7). While retrospective analyses found earlier initiation associated with completion, limitations in methodology preclude a cause-and-effect interpretation. Impact of age 9 vaccination is difficult to isolate in intervention studies that had multiple components. While initiating vaccination at age 9 is feasible, questions remain regarding the benefit of this approach to increase coverage.

Scientific approaches to defining HPV vaccine-induced protective immunity

Seventeen years after the licensure of prophylactic human papillomavirus (HPV) L1 virus-like-particle vaccines, a defined antibody level that correlates with vaccine-induced protection against HPV infections and associated neoplasia is missing. In contrast, correlates of protection have been defined for many viral vaccines, including for the hepatitis B virus (HBV) vaccine. This review includes lessons learned from vaccination against HBV and the use of an established protective HBV surface antigen antibody level: 10 mIU/mL, an overview of HPV infection-induced and HPV vaccine-induced antibody responses, successful efforts to establish international standardization of serological reagents and associated tools, and 15-year vigilance of HPV vaccine-induced antibody levels in a vaccination cohort against breakthrough infections. This report identifies progress but also gaps on the journey toward the definition of a HPV vaccine-induced correlate of protection.

Advances in cancer immunotherapy: historical perspectives, current developments, and future directions

Cancer immunotherapy, encompassing both experimental and standard-of-care therapies, has emerged as a promising approach to harnessing the immune system for tumor suppression. Experimental strategies, including novel immunotherapies and preclinical models, are actively being explored, while established treatments, such as immune checkpoint inhibitors (ICIs), are widely implemented in clinical settings. This comprehensive review examines the historical evolution, underlying mechanisms, and diverse strategies of cancer immunotherapy, highlighting both its clinical applications and ongoing preclinical advancements. The review delves into the essential components of anticancer immunity, including dendritic cell activation, T cell priming, and immune surveillance, while addressing the challenges posed by immune evasion mechanisms. Key immunotherapeutic strategies, such as cancer vaccines, oncolytic viruses, adoptive cell transfer, and ICIs, are discussed in detail. Additionally, the role of nanotechnology, cytokines, chemokines, and adjuvants in enhancing the precision and efficacy of immunotherapies were explored. Combination therapies, particularly those integrating immunotherapy with radiotherapy or chemotherapy, exhibit synergistic potential but necessitate careful management to reduce side effects. Emerging factors influencing immunotherapy outcomes, including tumor heterogeneity, gut microbiota composition, and genomic and epigenetic modifications, are also examined. Furthermore, the molecular mechanisms underlying immune evasion and therapeutic resistance are analyzed, with a focus on the contributions of noncoding RNAs and epigenetic alterations, along with innovative intervention strategies. This review emphasizes recent preclinical and clinical advancements, with particular attention to biomarker-driven approaches aimed at optimizing patient prognosis. Challenges such as immunotherapy-related toxicity, limited efficacy in solid tumors, and production constraints are highlighted as critical areas for future research. Advancements in personalized therapies and novel delivery systems are proposed as avenues to enhance treatment effectiveness and accessibility. By incorporating insights from multiple disciplines, this review aims to deepen the understanding and application of cancer immunotherapy, ultimately fostering more effective and widely accessible therapeutic solutions.

Serosurveillance to Support HPV Vaccination in England

Background

In 2020, the World Health Organization (WHO) declared a global strategy to accelerate the elimination of cervical cancer as a public health problem, for which high vaccination coverage rates are a key component. Since its inception in 2008, the UK national adolescent human papillomavirus (HPV) vaccination program has changed the vaccines being offered, the dosing regimen, and has become gender neutral.

Methods

We conducted serosurveillance to evaluate the magnitude and durability of vaccine-induced humoral immunity across various schedule changes, including changing from the bivalent to the quadrivalent vaccine, changes from a 3-dose to 2-dose schedule and inclusion of boys. It does not yet cover more recent schedule changes that include the nonavalent vaccine. Serostatus and antibody levels (in IU/mL) are reported for all nonavalent vaccine types.

Results

Our findings are consistent with data from clinical trials supporting durability of high vaccine-induced antibody levels through to adulthood (into the peak ages of exposure to sexually transmitted infections) and comparability between males and females.

Conclusions

These data support the utility of serosurveillance to monitor population level immunity to inform and evaluate national HPV vaccination programs. This ongoing serosurveillance aims to identify any reductions in vaccine-induced immunity that could foretell of a potential weakening in HPV control.

The socioeconomic burden of cervical cancer and its implications for strategies required to achieve the WHO elimination targets

INTRODUCTION

Cervical cancer is almost entirely preventable by vaccination and screening. Population-based vaccination and screening programs are effective and cost effective, but millions of people do not have access to these programs, causing immense suffering. The WHO Global Strategy for the elimination of cervical cancer as a public health problem calls for countries to meet ambitious vaccination, screening, and treatment targets.

AREAS COVERED

Epidemiological evidence indicates marked socioeconomic gradients in the burden of cervical cancer and vaccination, screening, and treatment coverage. The unacceptable socioeconomic burden of cervical cancer is largely a function of inequitable access to these programs. We discuss these inequities, and highlight strategies enabled by new evidence and technology. Single dose HPV vaccination, HPV-based screening, and the rapidly moving technology landscape have enabled task-shifting, innovation in service delivery and the possibility of scale. Equitable access to optimal care for the treatment of invasive cancers remains a challenge.

EXPERT OPINION

Cervical cancer can be eliminated equitably. It will require global political will, sustained public and private investment, and community leadership to safely and sustainably embed proven tools, technology and infrastructure in local health and knowledge systems.

Sexually transmitted human papillomavirus and related sequelae

SUMMARYMore than 40 types of sexually transmitted human papillomavirus (HPV) infect the oropharyngeal and anogenital mucosa-high-risk types are associated with precancerous and cancerous lesions of the cervix, vagina, vulva, penis, anus, and oropharynx, and low-risk types cause non-malignant disease, such as anogenital warts. Though most HPV infections resolve spontaneously, immunodeficiencies may result in persistent infection and increased risk of HPV-related sequelae. The mechanism by which HPV results in malignant transformation is multifaceted, involving interactions with numerous cellular pathways, the host immune system, and potentially the host microbiome. Vaccination against HPV is highly efficacious in the prevention of infection and related sequelae, and there now exist several approved formulations that protect against both high- and low-risk types. Despite the advent of vaccination, early detection and treatment of cervical and anal precancerous lesions continues to be integral to secondary prevention-molecular HPV testing, cytology, and tissue biopsy allow for triaging of patients, after which appropriate treatment with close follow-up can avert cancer development.

HIV, HPV, AND ORAL HEALTH IN TANZANIA: A SCOPING REVIEW

Background

There is an increased risk of human papillomavirus (HPV)-associated infections and malignancies among people living with HIV (PLHIV). However, there is limited literature exploring the intersection of HPV, HIV, and oral health in Tanzania and across sub-Saharan Africa. We reviewed the existing literature on the intersection of HIV, HPV, and oral health in Tanzania.

Methods

This was a scoping review with the search of key words representing HIV, HPV, oral health, and Tanzania. Since there were no studies that explored the intersection of HIV, HPV, and oral health in Tanzania, the search extended to include studies with the intersection between oral health and either HIV or HPV in Tanzania.

Findings

44 studies were eligible for analysis. Only one of them explored the relationship between HPV and oral health, where 4 (6%) of adolescent schoolgirls were detected with HPV-DNA and the paper hinted at the possibility of HPV autoinoculation. There were no articles linking HPV vaccination and oral health. The remaining 43 (98%) studies explored the relationship between HIV and oral health. There has been an increase in oral manifestations in PLHIV in the last two decades, and highly active antiretroviral therapy has been protective against oropharyngeal candidiasis but had no significance on head and neck cancer. Single-dose fluconazole and 35% herbal antifungals were identified to be effective in treating oral candidiasis. No recent studies explored the different facets of dental care among PLHIV.

Interpretation

There are no studies exploring the intersection of HIV, HPV, and oral health in Tanzania. Future studies are needed to determine the burden and barriers of HPV-associated oral manifestations among PLHIV in Tanzania and across Sub-Saharan Africa.

Global cervical cancer elimination: quantifying the status, progress, and gaps

BACKGROUND

To address the public health concern of cervical cancer (CC), 194 countries committed to eliminate it at the initiative of the World Health Organization (WHO). We summarised quantitative results concerning CC elimination across these countries, including the progress in implementing three prevention levels (human papillomavirus [HPV] vaccination, CC screening, and treatment for patients with CC) and achievement of interim Global Strategy for Cervical Cancer Elimination targets.

METHODS

Data were obtained from the International Agency for Research on Cancer, WHO, United Nations International Children's Emergency Fund, and country responses to the WHO National Capacity Survey on Non-Communicable Diseases. This retrospective analysis examined data from 194 countries and regions, stratified by national income (high-income countries (HICs) vs low- and middle-income countries (LMICs)) and geographic location (continents such as Europe, Asia, and North America). A quantitative assessment evaluated global progress in primary, secondary, and tertiary CC prevention.

RESULTS

By 2020, four countries had achieved Target 1 (90% of girls fully vaccinated against HPV by age 15). A total of 115 countries (51 (44.35%) HICs and 64 (55.65%) LMICs)) included HPV vaccination in their national immunisation programs. As of 2021, 133 countries (50 (37.59%) HICs and 83 (62.41%) LMICs)) implemented CC screening programs. Most of these were in Europe (41, 30.83%), Asia (32, 24.06%), and North America (20, 15.04%). Additionally, 126 countries (44 (34.92%) HICs and 82 (65.08%) LMICs)) had published national guidelines on CC management. These countries were primarily in Asia (32, 25.40%) and Europe (32, 25.40%). Furthermore, 69 countries provided palliative care under both scenarios. The 10 countries with the highest annual opioid consumption (excluding methadone) for CC, in oral morphine equivalence per capita (2017), were all HICs.

CONCLUSIONS

Major inequalities persist in CC vaccination and screening across 194 countries, and access to these services is limited in most LMICs. Focusing on vulnerable populations with lower incomes and regions with stunted economic growth may help alleviate inequity and accelerate CC elimination. We also found that tertiary prevention was achieved in most LMICs, but the indicator-reported annual opioid consumption in oral morphine equivalents indirectly illustrates the under-utilisation of cancer treatment services.

Durability of immunogenicity at 5 years after a single dose of human papillomavirus vaccine compared with two doses in Tanzanian girls aged 9-14 years: results of the long-term extension of the DoRIS randomised trial

BACKGROUND

WHO has recommended that one dose of human papillomavirus (HPV) vaccine can be given to individuals aged 9-20 years to prevent HPV infection. Estimating durability of immune responses after a single dose in the target age for vaccination is important. We report immunogenicity results in Tanzanian girls up to 5 years after receiving a dose.

METHODS

In this open-label, randomised controlled trial (the Dose Reduction Immunobridging and Safety Study of Two HPV Vaccines in Tanzanian Girls [DoRIS] trial), 930 Tanzanian schoolgirls aged 9-14 years were enrolled and randomly allocated to receive one, two, or three doses of either the two-valent vaccine (Cervarix; GSK, Wavre, Belgium) or nine-valent vaccine (Gardasil-9; Merck Sharp & Dohme, Haarlem, Netherlands). Seropositivity specific to HPV16 or HPV18, antibody geometric mean concentrations (GMCs), and antibody avidity were measured annually up to month 36. Participants in the one-dose and two-dose groups were followed annually in a long-term extension of the DoRIS trial to month 60; the primary outcome was seropositivity specific to HPV16 or HPV18 comparing one dose with two doses.

FINDINGS

Single-dose seropositivity for HPV16 IgG antibodies at month 60 with either vaccine was more than 99% and non-inferior to two doses. 98% of girls in the one-dose two-valent vaccine group and 93% in the one-dose nine-valent group were seropositive for HPV18 at month 60; however, the non-inferiority criteria for HPV18 seropositivity comparing one dose with two doses were not met. Although HPV16 and HPV18 antibody GMCs after one dose were lower than those observed after two doses, antibody GMCs in the one-dose groups remained stable from month 12 to month 60. There was no evidence of a difference between the one-dose and two-dose groups in HPV16 or HPV18 antibody avidity at month 36 for either vaccine.

INTERPRETATION

A single dose of HPV vaccine in girls aged 9-14 years continues to provide stable immune responses 5 years after vaccination, although ongoing surveillance for potential waning immunity after a single dose is needed. Participants are being followed up to 9 years after vaccination.

FUNDING

UK Department of Health and Social Care, UK Foreign, Commonwealth & Development Office, Global Challenges Research Fund, UK Medical Research Council, and the Wellcome Trust through the Joint Global Health Trials Scheme; Bill & Melinda Gates Foundation.

Modeling the health and economic implications of adopting a 1-dose 9-valent human papillomavirus vaccination program in adolescents in low/middle-income countries: An analysis of Indonesia

BACKGROUND

Recent evidence suggests that 1 dose of the human papillomavirus (HPV) vaccine may have similar effectiveness in reducing HPV infection risk compared to 2 or 3 doses.

OBJECTIVE

To evaluate the public health impact and cost-effectiveness of implementing a 1-dose or a 2-dose program of the 9-valent HPV vaccine in a low- and middle-income country (LMIC).

METHODS

We adapted a dynamic transmission model to the Indonesia setting, and conducted a probabilistic sensitivity analysis using distributions reflecting the uncertainty in levels and durability of protection of a 1-dose that were estimated under a Bayesian framework incorporating 3-year vaccine efficacy data from the KEN SHE trial (base-case) and 10 year effectiveness data from the India IARC study (alternative analysis). Scenarios included different coverage levels targeted at girls-only, or girls and boys. Costs and benefits were computed over 100 years from a national single-payer perspective.

RESULTS

Depending on the coverage and target population, the median number of cancer cases avoided in 2-dose programs ranged between 600,000-2,100,000, compared to 200,000-600,000 in 1-dose programs. The 1-dose programs are unlikely to be cost-effective compared to 2-dose programs even at low willingness-to-pay (WTP) thresholds. The girls-only 2-dose program tends to be cost-effective at lower WTP thresholds, particularly in scenarios with high coverage, dose price and discount rate, while the girls and boys 2-dose program is cost-effective at higher WTP thresholds. In the alternative analysis, 1-dose programs have higher probability of being cost-effective compared to the base-case, particularly for low WTP thresholds (less than 0.5 GDP) and for high coverage, dose price and discount rate.

CONCLUSION

Adoption of 1-dose programs with 9-valent vaccine in an LMIC resulted in more vaccine-preventable HPV-related cancer cases than 2-dose programs. The 2-dose programs were more likely to be cost-effective than 1-dose programs for a wide range of WTP thresholds and scenarios.

The effect of intermittent preventive treatment for malaria with dihydroartemisinin-piperaquine on vaccine-specific responses among schoolchildren in rural Uganda (POPVAC B): a double-blind, randomised controlled trial

BACKGROUND

Several important vaccines differ in immunogenicity and efficacy between populations. We hypothesised that malaria suppresses responses to unrelated vaccines and that this effect can be reversed-at least partially-by monthly malaria intermittent preventive treatment (IPT) in high-transmission settings.

METHODS

We conducted an individually randomised, double-blind, placebo-controlled trial of the effect of malaria IPT with dihydroartemisinin-piperaquine on vaccine responses among schoolchildren aged 9-17 years in Jinja district, Uganda. Participants were recruited from two schools and did not have exposure to vaccines of interest after the age of 5 years, with the exception of human papillomavirus (HPV). Computer-generated 1:1 randomisation was implemented in REDCap. 3-day courses of dihydroartemisinin-piperaquine (dosage by weight) or placebo were administered monthly, including twice before the first vaccination. Trial participants were vaccinated with the live parenteral BCG vaccine (Serum Institute of India, Pune, India) at week 0; yellow fever vaccine (YF-17D; Sanofi Pasteur, Lyon, France); live oral typhoid vaccine (Ty21a; PaxVax, London, UK), and quadrivalent virus-like particle HPV vaccine (Merck, Rahway, NJ, USA) at week 4; and toxoid vaccines (tetanus-diphtheria; Serum Institute of India) and an HPV booster at week 28. An additional HPV vaccination at week 8 was provided to female participants older than 14 years who had not previously been vaccinated, and a tetanus-diphtheria booster was given after completion of the trial at week 52. Primary outcomes were vaccine responses at week 8 and, for tetanus-diphtheria, at week 52, and analysis was done in the intention-to-treat population. Malaria parasite prevalence at enrolment and during follow-up was determined retrospectively by PCR. The safety population comprised all randomly allocated participants. The trial was registered at the ISRCTN Registry (ISRCTN62041885) and is complete.

FINDINGS

Between May 25 and July 14, 2021, we assessed 388 potential participants for eligibility. We enrolled and randomly allocated 341 participants to the two groups (170 [50%] to dihydroartemisinin-piperaquine and 171 [50%] to placebo); 192 (56%) were female and 149 (44%) participants were male. 145 (85%) participants in the dihydroartemisinin-piperaquine group and 140 participants (82%) in the placebo group were followed up until the week 52 endpoint. At enrolment, 109 (64%) of all participants in the dihydroartemisinin-piperaquine group and 99 (58%) of 170 participants in the placebo group had malaria; this reduced to 6% or lower at all follow-up visits in the dihydroartemisinin-piperaquine group. There was no effect of dihydroartemisinin-piperaquine versus placebo on primary outcomes: BCG-specific IFNγ ELISpot response had a geometric mean ratio (GMR) of 1·09 (95% CI 0·93-1·29), p=0·28; yellow fever neutralising antibody was 1·19 (0·91-1·54), p=0·20 for plaque reduction neutralising reference tests (PRNT50) titres (the reciprocal of the last plasma dilution that reduced by 50%) and 1·24 (0·97-1·58), p=0·09 for PRNT90 titres (reciprocal of the last plasma dilution that reduced by 90%); and IgG to Salmonella enterica serovar Typhi O-lipopolysaccharide was 1·09 (0·81-1·46), p=0·58, HPV-16 was 0·72 (0·44-1·77), p=0·19, HPV-18 was 0·71 (0·47-1·09), p=0·11; tetanus toxoid was 1·22 (0·91-1·62), p=0·18, and diphtheria toxoid was 0·97 (0·83-1·13), p=0·72. There was some evidence that dihydroartemisinin-piperaquine reduced waning of the yellow fever response.

INTERPRETATION

IPT for malaria with dihydroartemisinin-piperaquine did not improve peak vaccine responses, despite reducing malaria prevalence. Possible longer-term effects on response waning should be further explored.

FUNDING

UK Medical Research Council.

TRANSLATION

For the Luganda translation of the abstract see Supplementary Materials section.

Single-dose human papillomavirus vaccination: an update

Human papillomavirus (HPV) vaccines received regulatory approval and were recommended for use in young girls nearly 2 decades ago. Uptake is mostly high in resource-rich settings. In resource-limited settings, where the burden of cervical cancer is disproportionately high, access to and uptake of HPV vaccines are nowhere near satisfactory, despite evidence that HPV vaccination is highly cost-effective and a significant value-for-money investment. The discovery that only a single dose of the HPV vaccines may be needed to confer adequate protection may make equitable access to HPV vaccines possible. Indeed, the recent World Health Organization recommendation allowing for 1 or 2 doses is already gaining traction. This monograph aims to update the state of the science related to single-dose HPV vaccine protection and includes both primary data and modeling efforts that address key gaps in the knowledge regarding 1) durability of protection of a single dose of the HPV vaccine, 2) single-dose HPV vaccine effectiveness in both high-income and low-income settings, 3) implementation of single-dose HPV vaccination, and 4) how to accelerate control of cervical cancer by integrating a 1-time screen for cervical disease. The content published in this monograph will continue to advance the science of HPV vaccination and will be vital as new countries make informed decisions about how best to use this remarkable vaccine.

Community intervention of a single-dose or 2-dose regimen of bivalent human papillomavirus vaccine in schoolgirls in Thailand: vaccine effectiveness 2 years and 4 years after vaccination

BACKGROUND

With accumulating evidence of single-dose human papillomavirus (HPV) vaccine efficacy in young women, we conducted a community vaccine effectiveness study comparing HPV single-dose and 2-dose regimens (0 and 6 months) of a bivalent HPV vaccine among grade 8 schoolgirls (aged 13-14 years) in Thailand.

METHODS

In 2018, eligible grade 8 schoolgirls in Udon Thani (single dose) and Buri Ram (2 doses) provinces were offered HPV vaccine per assigned dose regimen. Concurrently, a cross-sectional survey for measuring baseline HPV prevalence was conducted in grade 10 (n = 2600) and grade 12 unvaccinated schoolgirls (n = 2000) in each province. HPV infection was assessed in first-void urine samples, tested by DNA polymerase chain reaction on the cobas 4800 system (Roche Molecular Diagnostics, Pleasanton, CA). All samples positive on the cobas system and an equal number of negative samples were also tested by Anyplex II HPV28 Detection (Seegene, Seoul, South Korea). The surveys were repeated in 2020 and 2022, when vaccinated grade 8 schoolgirls reached grade 10, and then subsequently grade 12, respectively. Vaccine effectiveness was estimated by comparing the weighted prevalence of HPV-16 or HPV-18 between grade-matched unvaccinated schoolgirls on the baseline survey (2018) and vaccinated schoolgirls in the year-2 (2020) and year-4 (2022) surveys. Adjustment methods were used in the analysis to account for potential differences in sexual behavior due to the noncontemporaneous comparison.

RESULTS

The prevalence of HPV-16 and HPV-18 on the baseline survey among unvaccinated grade 10/grade 12 schoolgirls was 2.90% (95% confidence interval [CI] = 2.54% to 3.31%)/3.98% (95% CI = 3.52% to 4.49%) for Udon Thani and 3.87% (95% CI = 3.46% to 4.34%)/6.13% (95% CI = 5.56% to 6.75%) for Buri Ram. On the year-2 survey, the prevalence among vaccinated grade 10 schoolgirls was 0.57% (95% CI = 0.42% to 0.77%) for Udon Thani and 0.31% (95% CI = 0.21% to 0.47%) for Buri Ram. The 2-year postvaccination crude vaccine effectiveness for the single-dose regimen was estimated at 80.4% (95% CI = 73.9% to 86.9%), and for the 2-dose regimen at 91.9% (95% CI = 88.5% to 95.4%). On the year-4 survey, the prevalence among vaccinated grade 12 schoolgirls was 0.37% (95% CI = 0.25% to 0.56%) for Udon Thani and 0.28% (95% CI = 0.18% to 0.45%) for Buri Ram. Four-year postvaccination crude vaccine effectiveness for the single-dose regimen was estimated at 90.6% (95% CI = 86.6% to 94.6%) and for the 2-dose regimen was estimated at 95.4% (95% CI = 93.2% to 97.6%). All adjustment methods minimally affected vaccine effectiveness for the single-dose and 2-dose regimens. At 4 years after vaccination, the difference in crude vaccine effectiveness between the single-dose and 2-dose regimens was ‒4.79% (95% CI = ‒9.32% to ‒0.25%), meeting the study's noninferiority criteria.

CONCLUSIONS

Our study demonstrated that both single-dose and 2-dose HPV vaccination significantly decreased HPV-16/18 point prevalence 2 years and 4 years after vaccination. Crude vaccine effectiveness at 4 years after vaccination was greater than 90% for both the single-dose and 2-dose regimens; the single-dose regimen was not inferior to the 2-dose regimen. These data show that a single dose of HPV vaccine provides high levels of protection when administered to schoolgirls younger than 15 years of age.

Human papillomavirus prophylactic vaccines: update on new vaccine development and implications for single-dose policy

Human papillomavirus (HPV) prophylactic vaccines were first licensed in 2006 with the primary goal of preventing HPV-related cancers, with cervical cancer accounting for the highest morbidity and mortality globally. Six HPV vaccines have been licensed; 4 of these have been prequalified by the World Health Organization, and additional products are in the pipeline. This article provides an overview of HPV vaccine coverage and current and anticipated vaccine supply vs expected demand. Given that the 2022 World Health Organization position paper on HPV vaccines includes a 1-dose regimen as an alternate schedule, we will discuss the evidence for using licensed vaccines in single-dose regimens and the approach to generating similar supportive data for other current and future vaccines. The broad adoption of a single-dose HPV vaccine regimen would expand access to vaccines by improving the supply-demand balance, increasing affordability, and simplifying logistics, which will ultimately impact HPV-related morbidity and mortality.

Looking Back, Moving Forward: Challenges and Opportunities for Global Cervical Cancer Prevention and Control

Despite the introduction of Pap testing for screening to prevent cervical cancer in the mid-20th century, cervical cancer remains a common cause of cancer-related mortality and morbidity globally. This is primarily due to differences in access to screening and care between low-income and high-income resource settings, resulting in cervical cancer being one of the cancers with the greatest health disparity. The discovery of human papillomavirus (HPV) as the near-obligate viral cause of cervical cancer can revolutionize how it can be prevented: HPV vaccination against infection for prophylaxis and HPV testing-based screening for the detection and treatment of cervical pre-cancers for interception. As a result of this progress, the World Health Organization has championed the elimination of cervical cancer as a global health problem. However, unless research, investments, and actions are taken to ensure equitable global access to these highly effective preventive interventions, there is a real threat to exacerbating the current health inequities in cervical cancer. In this review, the progress to date and the challenges and opportunities for fulfilling the potential of HPV-targeted prevention for global cervical cancer control are discussed.

Immunogenicity and Safety of Extended-Interval 2-Dose Regimens of 9vHPV Vaccine

BACKGROUND

Nine-valent human papillomavirus (9vHPV) vaccines can be administered in 2 doses 6 to 12 months apart in adolescents. The impact of extended dose intervals is unknown. We report immunogenicity and safety data in adolescents of a second 9vHPV vaccine dose administered ≥1 year after the first.

METHODS

This open-label safety and immunogenicity study (NCT04708041) assessed extended-interval 2-dose regimens of 9vHPV vaccine among adolescents (10 to 15 years) who received 2 9vHPV vaccine doses: the first ≥1 year before enrollment, and second, at enrollment (day 1). We measured serologic responses to vaccine-targeted human papillomavirus (HPV) types at enrollment day 1 (pre-dose 2) and 1 month post-dose 2 (month 1) using a competitive LuminexV® immunoassay. We estimated effects of dose interval on geometric mean titers (GMTs) using regression modeling. Participants reported adverse events (AEs) through 15 days after vaccination.

RESULTS

We enrolled 146 adolescents (mean age 13.3 years) with median 25 months since first 9vHPV vaccine dose (range: 12-53 months). Across vaccine-targeted HPV types, GMTs increased from day 1 to month 1; seropositivity at month 1 was 100%. Anti-HPV GMTs at month 1 were not affected by differences in dose interval of 12 to 53 months, based on regression modeling. The most common AEs were mild-to-moderate injection site reactions; no serious AEs were reported.

CONCLUSIONS

Extending the interval between first and second 9vHPV vaccine doses to 12 to 53 months did not affect antibody responses, with favorable safety profile. These results support feasibility of extended interval regimens for 9vHPV vaccine.

Efficacy and immunogenicity of a single dose of human papillomavirus vaccine compared to multidose vaccination regimens or no vaccination: An updated systematic review of evidence from clinical trials

Objectives

This study systematically reviewed the published literature from clinical trials on the efficacy and immunogenicity of single-dose HPV vaccination compared to multidose schedules or no HPV vaccination.

Methods

Four databases were searched for relevant articles published from Jan-1999 to Feb-2023. Articles were assessed for eligibility for inclusion using pre-defined criteria. Relevant data were extracted from eligible articles and a descriptive quality assessment was performed for each study. A narrative data synthesis was conducted, examining HPV infection, other clinical outcomes and immunogenicity responses by dose schedule.

Results

Fifteen articles reporting data from six studies (all in healthy young females) were included. One article was included from each of three studies that prospectively randomised participants to receive a single HPV vaccine dose versus one or more comparator schedule(s). The other 12 articles reported data from three studies that randomised participants to receive multidose HPV vaccine (or control vaccine) schedules; in those studies, some participants failed to complete their allocated schedule, and evaluations were conducted to compare participants who actually received one, two or three doses. Across all efficacy studies, the incidence or prevalence of HPV16/18 infection was very low among HPV-vaccinated participants, regardless of the number of doses received; with no evidence for a difference between dose groups. In immunogenicity studies, HPV16/18 antibody seropositivity rates were high among all HPV-vaccinated participants. Antibody levels were significantly lower with one dose compared to two or three doses, but levels with one dose were stable and sustained to 11 years post-vaccination.

Conclusions

Results from this review support recent World Health Organization recommendations allowing either one- or two-dose HPV vaccination in healthy young females. Longer-term efficacy and immunogenicity data from ongoing studies are awaited. Randomised trials of single-dose HPV-vaccination are urgently needed in other populations, e.g. boys, older females and people with HIV.

Evidence for an HPV one-dose schedule

The World Health Organization has recently updated their dosing schedule recommendations for the human papillomavirus (HPV) vaccine to include a single-dose schedule. We review the biologic plausibility of a single dose, the evidence from clinical trials, post-licensure observational studies, and mathematical modeling for a single-dose schedule. We also discuss the implications of countries switching to a single-dose program from a two or three-dose schedule. Finally, we review the countries that have currently switched to or introduced the vaccine with a single-dose schedule.

Safety and immunogenicity of Innovax bivalent human papillomavirus vaccine in girls 9-14 years of age: Interim analysis from a phase 3 clinical trial

BACKGROUND

World Health Organization human papillomavirus (HPV) vaccination recommendations include a single- or two-dose schedule in individuals 9-20 years old and advice for generating data on single-dose efficacy or immunobridging. The ongoing Phase 3 trial of Innovax's bivalent (types 16 and 18) HPV vaccine (Cecolin®) assesses in low- and middle-income countries alternative dosing schedules and generates data following one dose in girls 9-14 years old. Interim data for the 6-month dosing groups are presented.

METHODS

In Bangladesh and Ghana, 1,025 girls were randomized to receive either two doses of Cecolin at 6-, 12-, or 24-month intervals; one dose of Gardasil® followed by one dose of Cecolin at month 24; or two doses of Gardasil 6 months apart (referent). Serology was measured by enzyme-linked immunosorbent assay (ELISA) and, in a subset, by neutralization assays. Primary objectives include immunological non-inferiority of the Cecolin schedules to referent one month after the second dose. Safety endpoints include reactogenicity and unsolicited adverse events for 7 and 30 days post-vaccination, respectively, as well as serious adverse events throughout the study.

RESULTS

Interim analyses included data from the two groups on a 0, 6-month schedule with 205 participants per group. One month after Dose 2, 100% of participants were seropositive by ELISA and had seroconverted for both antigens. Non-inferiority of Cecolin to Gardasil was demonstrated. Six months following one dose, over 96% of participants were seropositive by ELISA for both HPV antigens, with a trend for higher geometric mean concentration following Cecolin administration. Reactogenicity and safety were comparable between both vaccines.

CONCLUSIONS

Cecolin in a 0, 6-month schedule elicits robust immunogenicity. Non-inferiority to Gardasil was demonstrated one month after a 0, 6-month schedule. Immunogenicity following one dose was comparable to Gardasil up to six months. Both vaccines were safe and well tolerated (ClinicalTrials.gov No. 04508309).

Comparing one dose of HPV vaccine in girls aged 9-14 years in Tanzania (DoRIS) with one dose in young women aged 15-20 years in Kenya (KEN SHE): an immunobridging analysis of randomised controlled trials

BACKGROUND

The first randomised controlled trial of single-dose human papillomavirus (HPV) vaccine efficacy, the Kenya single-dose HPV-vaccine efficacy (KEN SHE) trial, showed greater than 97% efficacy against persistent HPV16 and HPV18 infection at 36 months among women in Kenya. We compared antibody responses after one dose of HPV vaccine in the Dose Reduction Immunobridging and Safety Study (DoRIS), the first randomised trial of the single- dose regimen in girls aged 9-14 years, the target age range for vaccination, with those after one dose of the same vaccine in KEN SHE.

METHODS

In the DoRIS trial, 930 girls aged 9-14 years in Tanzania were randomly assigned to one, two, or three doses of the 2-valent vaccine (Cervarix) or the 9-valent vaccine (Gardasil-9). The proportion seroconverting and geometric mean concentrations (GMCs) at month 24 after one dose were compared with those in women aged 15-20 years who were randomly assigned to one dose of the same vaccines at the same timepoint in KEN SHE. Batched samples were tested together by virus-like particle ELISA for HPV16 and HPV18 IgG antibodies. Non-inferiority of GMC ratios (DoRIS trial:KEN SHE) was predefined as a lower bound of the 95% CI less than 0·50.

FINDINGS

Month 24 HPV16 and HPV18 antibody GMCs in DoRIS were similar or higher than those in KEN SHE. 2-valent GMC ratios were 0·90 (95% CI 0·72-1·14) for HPV16 and 1·02 (0·78-1·33) for HPV18. 9-valent GMC ratios were 1·44 (95% CI 1·14-1·82) and 1·47 (1·13-1·90), respectively. Non-inferiority of antibody GMCs and seropositivity was met for HPV16 and HPV18 for both vaccines.

INTERPRETATION

HPV16 and HPV18 immune responses in young girls 24 months after a single dose of 2-valent or 9-valent HPV vaccine were comparable to those in young women who were randomly assigned to a single dose of the same vaccines and in whom efficacy had been shown. A single dose of HPV vaccine, when given to girls in the target age range for vaccination, induces immune responses that could be effective against persistent HPV16 and HPV18 infection at least two years after vaccination.

FUNDING

The UK Department of Health and Social Care, the Foreign, Commonwealth, & Development Office, the Global Challenges Research Fund, the UK Medical Research Council and Wellcome Trust Joint Global Health Trials scheme, the Bill and Melinda Gates Foundation, the US National Cancer Institute; the US National Institutes of Health, and the Francis and Dorothea Reed Endowed Chair in Infectious Diseases.

TRANSLATION

For the KiSwahili translation of the abstract see Supplementary Materials section.

A comprehensive narrative review of challenges and facilitators in the implementation of various HPV vaccination program worldwide

INTRODUCTION

Cervical cancer has been considered as one of the most common cancers in women (15-44 years) globally, but the advent of the human papilloma virus (HPV) vaccine has raised the anticipation that eradication of cervical carcinoma might be achieved in the near future as several prophylactic cervical carcinoma vaccines have already been currently licensed in various countries. Countries should devise strategies, practices and policies to attain and sustain higher levels of HPV immunization coverage as still 68% countries have introduced HPV vaccine in their national immunization programs even after 17 years following the licensure of the first prophylactic HPV vaccine.

METHODOLOGY

A comprehensive literature analysis was conducted using various databases and search engines, to include the most relevant research articles and data available and critically discussed the operational gaps that need to be answered to achieve adequate coverage of HPV vaccination.

RESULTS

The present review highlights the existing HPV vaccination strategies, unmet needs and challenges needed to be addressed for proper implementation framework as well as the collaborations required to achieve decent vaccination coverage. Well-coordinated vaccination strategy with focus on adolescent girls and if possible, boys can lead to dramatic impact on disease reduction around the world.

The clinical effectiveness of one-dose vaccination with an HPV vaccine: A meta-analysis of 902,368 vaccinated women

BACKGROUND

The comprehensive effectiveness of the HPV vaccine has been widely acknowledged. However, challenges such as dosing adherence and limited budgets have led to delays in HPV vaccination implementation in many countries. A potential solution to these issues could lie in a one-dose vaccination with an HPV vaccine, as indicated by promising outcomes in multiple studies.

METHODS

In this systematic review and meta-analysis, we examine the comparative effectiveness of the one-dose vaccination with an HPV vaccine against two- and three-dose regimens. Our investigation focuses on clinical efficacy, encompassing the prevention of HPV16, HPV18, and hrHPV infections, HSIL or ASC-H incidence, and CIN2/3 incidence.

RESULTS

Our analysis suggests that a single-dose HPV vaccine may offer effectiveness on par with two- or three-dose schedules. This conclusion is drawn from its capacity to confer immunogenic protection for at least 8 years of follow-up, coupled with its ability to mitigate infections and pre-cancerous occurrences.

CONCLUSION

While our findings underscore the potential of the one-dose vaccination with an HPV vaccine, further research and prolonged study durations are necessary to establish robust evidence supporting this recommendation. As such, continued investigation will be critical for informing vaccination strategies.

Durability of single-dose HPV vaccination in young Kenyan women: randomized controlled trial 3-year results

Cervical cancer burden is high where prophylactic vaccination and screening coverage are low. We demonstrated in a multicenter randomized, double-blind, controlled trial that single-dose human papillomavirus (HPV) vaccination had high vaccine efficacy (VE) against persistent infection at 18 months in Kenyan women. Here, we report findings of this trial through 3 years of follow-up. Overall, 2,275 healthy women aged 15-20 years were recruited and randomly assigned to receive bivalent (n = 760), nonavalent (n = 758) or control (n = 757) vaccine. The primary outcome was incident-persistent vaccine type-specific cervical HPV infection. The primary evaluation was superiority analysis in the modified intention-to-treat (mITT) HPV 16/18 and HPV 16/18/31/33/45/52/58 cohorts. The trial met its prespecified end points of vaccine type-specific persistent HPV infection. A total of 75 incident-persistent infections were detected in the HPV 16/18 mITT cohort: 2 in the bivalent group, 1 in the nonavalent group and 72 in the control group. Nonavalent VE was 98.8% (95% CI 91.3-99.8%, P < 0.0001) and bivalent VE was 97.5% (95% CI 90.0-99.4%, P < 0.0001). Overall, 89 persistent infections were detected in the HPV 16/18/31/33/45/52/58 mITT cohort: 5 in the nonavalent group and 84 in the control group; nonavalent VE was 95.5% (95% CI 89.0-98.2%, P < 0.0001). There were no vaccine-related severe adverse events. Three years after vaccination, single-dose HPV vaccination was highly efficacious, safe and conferred durable protection. ClinicalTrials.gov no. NCT03675256 .

Is immunotherapy a potential game changer in managing human papillomavirus (HPV) infection and intraepithelial neoplasia?

The International Papillomavirus Conference was held in Washington DC in April 2023 and encompassed wide ranging basic, clinical and public health research relating to animal and human papillomaviruses. This editorial is a personal reflection, it does not attempt to be comprehensive and reports on some key aspects centred on the prospects for immune interventions in prevention and treatment of HPV infections and early precancers with a focus on cervical neoplasia. There is optimism for the future impact of immunotherapy in treating early HPV associated disease. This will depend on developing an appropriate design of vaccines and delivery vehicles which then need to be properly tested in clinical trials that are able to measure a useful clinical endpoint. Thereafter vaccines (prophylactic or therapeutic) still need global access and sufficient uptake to deliver impact and a key and necessary driver is education.

The potential of PCNA inhibition as a therapeutic strategy in cervical cancer

Cervical cancers are the fourth most common and most deadly cancer in women worldwide. Despite being a tremendous public health burden, few novel approaches to improve care for these malignancies have been introduced. We discuss the potential for proliferating cell nuclear antigen (PCNA) inhibition to address this need as well as the advantages and disadvantages for compounds that can therapeutically inhibit PCNA with a specific focus on cervical cancer.

Natural and synthetic drugs and formulations for intravaginal HPV clearance

BACKGROUND

Except for a few preventative Human Papillomavirus (HPV) vaccines, there is currently no cure for HPV infection. There are a number of cutting-edge strategies and potent medications or herbal formulations that can be applied topically for early clearance of HPV infection before HPV DNA gets integrated into host cell genome. This is facilitated due to cervical cancer having distinct and well-recognized long precancerous stages.

OBJECTIVES

This review aims to outline every possible medication and formulation, both natural and synthetic, that can be applied topically as intravaginal application to help remove HPV infection at an early precancerous stage.

RESULTS

Several anti-HPV/HPV clearance compounds and formulations for high-grade lesions are undergoing clinical trials. However, the majority of compounds are still in the early stages of development and require additional research to become viable HPV clearance candidates. Synthetic drugs may be more promising because they may have a more targeted effect; however, they may also have significant adverse effects. On the other hand, natural medications are safer to use. They are less specific, but have minimal to no adverse effects.

CONCLUSIONS

This article may serve as a valuable resource of information for managing and preventing precancerous carcinogenic HPV infections. Research could be directed toward developing candidate drugs to make evidence-based decisions about advancing them to clinical trials and, eventually, to the market for potential use in the prevention and control of cervical cancer, which is almost always preventable or even curable if detected early.

Human Papillomavirus-Associated Oropharyngeal Cancer: Global Epidemiology and Public Policy Implications

Global trends in human papillomavirus (HPV)-associated head and neck cancers (HNC), specifically in the oropharynx subsite, have been dynamically changing, leading to new staging and treatment paradigms. Epidemiologic studies have noted regional variations in HPV-associated oropharyngeal squamous cell carcinoma (OPSCC). While HPV vaccination remains the main preventative approach, vaccination policy in relation to gender neutrality is heterogeneous and particularly sparse in low- and middle-income countries, where the burden of global cancer cases and HPV-associated HNC are not well-characterized in certain regions. This review summarizes the existing literature on regional variations of HPV-associated OPSCC and gender-neutral vaccine policies. Based on available data, the incidence of HPV-associated OPSCC is highest in North America, Europe, and Oceania. As of 2022, 122 of 195 (63%) World Health Organization (WHO) member states had incorporated HPV vaccinations nationally; of these, 41 of 122 (34%) member states have introduced gender-neutral vaccine coverage. Future research is needed to describe continued evolving trends in HPV-associated OPSCC, understand underlying risk factors leading to regional variation in disease, and implement gender-neutral policy more broadly.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A protective, single-visit TB vaccination regimen by co-administration of a subunit vaccine with BCG

The only licensed tuberculosis (TB) vaccine, Bacillus Calmette Guerin (BCG), fails to reliably protect adolescents and adults from pulmonary TB, resulting in ~1.6 million deaths annually. Protein subunit vaccines have shown promise against TB in clinical studies. Unfortunately, most subunit vaccines require multiple administrations, which increases the risk of loss to follow-up and necessitates more complex and costly logistics. Given the well-documented adjuvant effect of BCG, we hypothesized that BCG co-administration could compensate for a reduced number of subunit vaccinations. To explore this, we developed an expression-optimized version of our H107 vaccine candidate (H107e), which does not cross-react with BCG. In the CAF®01 adjuvant, a single dose of H107e induced inferior protection compared to three H107e/CAF®01 administrations. However, co-administering a single dose of H107e/CAF®01 with BCG significantly improved protection, which was equal to BCG co-administered with three H107e/CAF®01 doses. Importantly, combining BCG with a single H107e/CAF®01 dose also increased protection in previously BCG-primed animals. Overall, a single dose of H107e/CAF®01 with BCG induced long-lived immunity and triggered BCG-specific Th17 responses. These data support co-administration of BCG and subunit vaccines in both BCG naïve and BCG-primed individuals as an improved TB vaccine strategy with reduced number of vaccination visits.

Communication strategies to improve human papillomavirus (HPV) immunisation uptake among adolescents in sub-Saharan Africa: a systematic review and meta-analysis

OBJECTIVES

Developing countries face the greatest cervical cancer disease burden and mortality with suboptimal immunisation uptake. This review explores the communication strategies adopted, successes, challenges and lessons learnt in sub-Saharan countries to enhance human papillomavirus (HPV) immunisation.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Hinari, Cochrane Library, Trip database, CINAHL, Web of Science, Scopus and seven grey resources were searched through May 2022.

ELIGIBILITY CRITERIA

We included observational studies addressing communication strategies for HPV immunisation uptake.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers used standardised methods to search, screen and code included studies. Data extraction and assessment of risk of bias were done in duplicate to enhance validity of the results. Meta-analysis was conducted using the random-effects model. Findings were summarised and synthesised qualitatively.

RESULTS

Communication intervention to facilitate decision-making achieved uptake rate of 100% (95% CI 0.99% to 1.00%), followed by intervention to enable communication, which achieved 92% (95% CI 0.92% to 0.92%). Communication intervention to inform and educate achieved 90% (95% CI 0.90% to 0.90%).Targeting both healthcare workers and community leaders with the communication intervention achieved 95% (95% CI 0.91% to 0.98%), while teachers and school boards achieved 92% (95% CI 0.84% to 1.01%). Targeting policymakers achieved 86% (95% CI 0.78% to 0.93%).Based on the method of communication intervention delivery, use of training achieved an uptake rate of 85% (95% CI 0.84% to 0.87%); similarly, drama and dance achieved 85% (95% CI 0.84% to 0.86%). However, use of information, education and communication materials achieved 82% (95% CI 0.78% to 0.87%).

CONCLUSION

HPV vaccine communication is critical in ensuring that the community understands the importance of vaccination. The most effective communication strategies included those which educate the population about the HPV vaccine, facilitate decision-making on vaccine uptake and community ownership of the vaccination process immunisation.

PROSPERO REGISTRATION NUMBER

CRD42021243683.

HPV vaccination programs in LMIC: is it time to optimize schedules and recommendations?

OBJECTIVES

Prophylactic HPV vaccines are a fundamental tool to reduce infections and tumors caused by the most prevalent types of these viruses, as this review points out. Several countries have adopted immunization programs that recommend vaccination against HPV for girls and adolescents between 9 and 14 years of age and, in some of them, also for boys. The programs also contemplate the immunization of adults, particularly in the case of individuals with different immunodeficiencies.

SOURCES OF DATA

The available vaccines are recommended for the prevention of tumors of the uterine cervix, vulva, vagina, penis, and anal canal. Moreover, two of the vaccines prevent the occurrence of genital warts, having been recently indicated for the prevention of oropharyngeal cancer.

DATA SYNTHESIS

Based on the evidence that antibody responses in girls were non-inferior after two doses when compared to three doses, several countries have decided to reduce the vaccination schedule for girls and boys up to 14 years of age from three to two doses, with an interval of six months between them. Recently, knowledge has been accumulating about the immunogenicity, duration of protection, and efficacy of a single-dose HPV vaccine regimen in girls and young women.

CONCLUSION

Single-dose HPV vaccination could substantially reduce the incidence of pre-cancer and cervical cancer attributable to HPV, with reduced costs for vaccine delivery and simplified implementation, allowing more countries to introduce HPV vaccination or increase the adherence of the target population.

Effectiveness of quadrivalent HPV vaccination in reducing vaccine-type and nonvaccine-type high risk HPV infection

This study aimed to assess human papillomavirus (HPV) vaccine effectiveness (VE) against both vaccine-type and nonvaccine-type high-risk HPV (hrHPV) infection, and duration of protection in United States. The study population was female participants aged 18-35 years with an HPV vaccination history and genital testing for HPV from the National Health and Nutrition Examination Survey, 2007-2016. Participants vaccinated before sexual debut were assessed against 13 nonvaccine-type hrHPV infection including 31/33/35/39/45/51/52/56/58/59/68/73/82. Multivariable logistic regression was used to estimate VE overall, by age at diagnosis, time since vaccination and lifetime sexual partners. A total of 3866 women were included in the analysis, with 23.3% (95% CI 21.3%-25.4%) having been vaccinated (≥1 dose). VE against vaccine-type HPV18/16/11/6 infection was 58% overall, which was mainly driven by those aged 18-22 years (VE = 64%) and 23-27 years (65%). Among participants aged 18-22 years vaccinated before sexual debut, the VE was 47% (23%-64%) against 13 nonvaccine-type hrHPV and 61% (95% CI 36%-77%) against 5 selected nonvaccine-type hrHPV35/39/52/58/59. Both direct effectiveness and cross-protection maintained effective for 5-10 years post vaccination. We also found the prevalence of ever diagnosed cervical cancer among vaccinated was significantly lower (0.46%, 4/874) than that among unvaccinated participants (1.27%, 38/2992). These findings highlight the potential of significant reduction of cervical cancer following the universal HPV vaccination programme.

Costs of delivering human papillomavirus vaccination using a one- or two-dose strategy in Tanzania

OBJECTIVE

As part of the Dose Reduction Immunobridging and Safety Study of Two HPV Vaccines in Tanzanian Girls (DoRIS; NCT02834637), the current study is one of the first to evaluate the financial and economic costs of the national rollout of an HPV vaccination program in school-aged girls in sub-Saharan Africa and the potential costs associated with a single dose HPV vaccine program, given recent evidence suggesting that a single dose may be as efficacious as a two-dose regimen.

METHODS

The World Health Organization's (WHO) Cervical Cancer Prevention and Control Costing (C4P) micro-costing tool was used to estimate the total financial and economic costs of the national vaccination program from the perspective of the Tanzanian government. Cost data were collected in 2019 via surveys, workshops, and interviews with local stakeholders for vaccines and injection supplies, microplanning, training, sensitization, service delivery, supervision, and cold chain. The cost per two-dose and one-dose fully immunized girl (FIG) was calculated.

RESULTS

The total financial and economic costs were US$10,117,455 and US$45,683,204, respectively, at a financial cost of $5.17 per two-dose FIG, and an economic cost of $23.34 per FIG. Vaccine and vaccine-related costs comprised the largest proportion of costs, followed by service delivery. In a one-dose scenario, the cost per FIG reduced to $2.51 (financial) and $12.18 (economic), with the largest reductions in vaccine and injection supply costs, and service delivery.

CONCLUSIONS

The overall cost of Tanzania's HPV vaccination program was lower per vaccinee than costs estimated from previous demonstration projects in the region, especially in a single-dose scenario. Given the WHO Strategic Advisory Group of Experts on Immunization's recent recommendation to update dosing schedules to either one or two doses of the HPV vaccine, these data provide important baseline data for Tanzania and may serve as a guide for improving coverage going forward. The findings may also aid in the prioritization of funding for countries that have not yet added HPV vaccines to their routine immunizations.

HPV vaccination coverage and factors among American Indians in Cherokee Nation

PURPOSE

We estimated human papillomavirus (HPV) vaccine initiation coverage among American Indian adolescents and identified factors associated with HPV vaccination among parents of these adolescents.

METHODS

We developed, tested, and disseminated a survey to a random sample of 2,000 parents of American Indian adolescents aged 9-17 years who had accessed Cherokee Nation Health Services from January 2019 to August 2020. We used log-binomial regression to estimate the unadjusted and adjusted weighted prevalence proportion ratios (PPR) and 95% confidence intervals (CI) for adolescent HPV vaccine initiation.

RESULTS

HPV vaccine initiation coverage (≥ 1 dose) was 70.7% among adolescents aged 13-17 years. The prevalence of HPV vaccine initiation was higher among American Indian adolescents whose parents were aware of the HPV vaccine (adjusted weighted PPR 3.41; 95% CI 2.80, 4.15) and whose parents received a recommendation from their provider (adjusted weighted PPR 2.70; 95% CI 2.56, 2.84). The most common reasons reported by parents to vaccinate their children were to protect them against HPV-associated cancers (25.7%) and receiving a recommendation from a healthcare provider (25.0%). Parents cited vaccine safety concerns as the main reason for not getting their children vaccinated (33.2%).

CONCLUSIONS

HPV vaccine initiation coverage among American Indian adolescents in Cherokee Nation was consistent with the national survey estimates. However, allaying parental concerns about vaccine safety and encouraging providers to recommend the HPV vaccine could improve coverage.

Immunogenicity and safety of one-dose human papillomavirus vaccine compared with two or three doses in Tanzanian girls (DoRIS): an open-label, randomised, non-inferiority trial

BACKGROUND

An estimated 15% of girls aged 9-14 years worldwide have been vaccinated against human papillomavirus (HPV) with the recommended two-dose or three-dose schedules. A one-dose HPV vaccine schedule would be simpler and cheaper to deliver. We report immunogenicity and safety results of different doses of two different HPV vaccines in Tanzanian girls.

METHODS

In this open-label, randomised, phase 3, non-inferiority trial, we enrolled healthy schoolgirls aged 9-14 years from Government schools in Mwanza, Tanzania. Eligible participants were randomly assigned to receive one, two, or three doses of either the 2-valent vaccine (Cervarix, GSK Biologicals, Rixensart) or the 9-valent vaccine (Gardasil-9, Sanofi Pasteur MSD, Lyon). The primary outcome was HPV 16 specific or HPV 18 specific seropositivity following one dose compared with two or three doses of the same HPV vaccine 24 months after vaccination. Safety was assessed as solicited adverse events up to 30 days after each dose and unsolicited adverse events up to 24 months after vaccination or to last study visit. The primary outcome was done in the per-protocol population, and safety was analysed in the total vaccinated population. This study was registered in ClinicalTrials.gov, NCT02834637.

FINDINGS

Between Feb 23, 2017, and Jan 6, 2018, we screened 1002 girls for eligibility. 72 girls were excluded. 930 girls were enrolled and randomly assigned to receive one dose of Cervarix (155 participants), two doses of Cervarix (155 participants), three doses of Cervarix (155 participants), one dose of Gardasil-9 (155 participants), two doses of Gardasil-9 (155 participants), or three doses of Gardasil-9 (155 participants). 922 participants received all scheduled doses within the defined window (three withdrew, one was lost to follow-up, and one died before completion; two received their 6-month doses early, and one received the wrong valent vaccine in error; all 930 participants were included in the total vaccinated cohort). Retention at 24 months was 918 (99%) of 930 participants. In the according-to-protocol cohort, at 24 months, 99% of participants who received one dose of either HPV vaccine were seropositive for HPV 16 IgG antibodies, compared with 100% of participants who received two doses, and 100% of participants who received three doses. This met the prespecified non-inferiority criteria. Anti-HPV 18 seropositivity at 24 months did not meet non-inferiority criteria for one dose compared to two doses or three doses for either vaccine, although more than 98% of girls in all groups had HPV 18 antibodies. 53 serious adverse events (SAEs) were experienced by 42 (4·5%) of 930 girls, the most common of which was hospital admission for malaria. One girl died of malaria. Number of events was similar between groups and no SAEs were considered related to vaccination.

INTERPRETATION

A single dose of the 2-valent or 9-valent HPV vaccine in girls aged 9-14 years induced robust immune responses up to 24 months, suggesting that this reduced dose regimen could be suitable for prevention of HPV infection among girls in the target age group for vaccination.

FUNDING

UK Department for International Development/UK Medical Research Council/Wellcome Trust Joint Global Health Trials Scheme, The Bill & Melinda Gates Foundation, and the US National Cancer Institute.

TRANSLATION

For the KiSwahili translation of the abstract see Supplementary Materials section.