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Adding Male Single Dose HPV Vaccination to Female HPV Vaccination in Tanzania

Adding Male Single Dose HPV Vaccination to Female HPV Vaccination in Tanzania

Status
Recruiting
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04953130
Acronym
Add-Vacc
Enrollment
10400
Registered
2021-07-07
Start date
2022-08-01
Completion date
2026-12-01
Last updated
2026-09-08

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

HPV Infection, Vaccine Preventable Disease

Brief summary

Add-Vacc is an unblinded cluster-randomised trial (CRT) with two arms: (i) the national HPV vaccination programme (girls aged \ 14 years, control arm) and (ii) the national programme plus single-dose male HPV vaccination given to a multi-year cohort of boys (intervention arm). The CRT will be conducted in 26 communities/clusters (13 per arm) in northern Tanzania. Boys aged 14 to 18 years in the intervention arm will receive one dose of the 4-valent HPV vaccine (Gardasil®) that protects against HPV 6, 11, 16, and 18. Population genital HPV prevalence in 18 to 21-year-olds will be compared between intervention clusters (female and male vaccination) and control clusters (female vaccination only) at 3 years after the intervention. Blood sampling for immune responses and adverse event data collection will be performed in a subset of 200 male subjects in selected intervention clusters.

Interventions

Single dose 4-valent HPV vaccine in males. Gardasil®, manufactured by MSD, consists of a licensed prophylactic virus-like particle (VLP) vaccine that protects against 4 HPV genotypes (HPV 6, 11, 16, 18).

Sponsors

London School of Hygiene and Tropical Medicine
Lead SponsorOTHER
Mwanza Intervention Trials Unit, National Institute for Medical Research
CollaboratorUNKNOWN
York Biomedical Research Institute, Hull York Medical School, University of York
CollaboratorUNKNOWN
Cancer Epidemiology Research Programme Institut Català d' Oncologia
CollaboratorUNKNOWN
Karolinska Institute Department of Laboratory Medicine
CollaboratorUNKNOWN
University of Cambridge
CollaboratorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Outcomes Assessor)

Intervention model description

Cluster randomised trial with 26 communities (13 per arm)

Eligibility

Sex/Gender
MALE
Age
14 Years to 18 Years
Healthy volunteers
Yes

Inclusion criteria

* Parents and adult male participants (aged 18 years) must sign an ICF and male participants aged less than 18 years must sign an informed assent form (IAF), indicating that they understand the purpose of and procedures required for the study and are willing to participate in the study and to receive HPV vaccination. If the parent or participant cannot read or write, the procedures must be explained and informed consent/assent must be witnessed by a literate third party who is not involved in the conduct of the study. * Participants must have been born male, and must be aged 14 to 18 years inclusive at time of vaccination. * Participants must be living in an intervention community (cluster). * Participants must be willing and able to comply with the protocol requirements. * Participants must agree to avoid all non-trial immunisations in the 14 days following vaccination with the trial vaccine, other than emergency vaccinations such as post-exposure rabies or tetanus vaccinations. * Participants must be healthy as determined by a medical history. A physical examination will be conducted if necessary according to the clinician's judgement.

Exclusion criteria

Boys will be excluded from HPV vaccination if: * They have previously been vaccinated against HPV. * They have a history of allergy or anaphylaxis to one or more of the HPV vaccine components, to yeast or to latex. * They are enrolled in another vaccine research study that specifically specifies that they must not participate in a study of another vaccine * They have been diagnosed with a chronic condition (except HIV, as per the comment above), such as an autoimmune condition, sickle cell disease, degenerative disease, neurologic or genetic disease, among others; * There are significant conditions or clinically significant findings for which, in the opinion of the investigator, participation would not be in the best interest of the participant (e.g., it would compromise their safety or well-being).

Design outcomes

Primary

MeasureTime frameDescription
Impact of adding single-dose male HPV vaccination to the national HPV vaccination programme in girls on population 4-valent HPV genotype prevalence in 18 to 21-year-old females and malesMonth 36Prevalence of 4-valent vaccine HPV genotype DNA (HPV 6, 11, 16 or 18) in males and females aged 18 to 21 years in intervention clusters and control clusters 36 months post-male vaccination

Secondary

MeasureTime frameDescription
Cost-effectiveness of adding a multi-year single dose male HPV vaccination strategy to the national female HPV vaccination programmeMonth 36Incremental cost-effectiveness ratio for single dose male vaccination plus existing female vaccination programme compared to female vaccination only
Immunogenicity and safety of single dose 4-valent HPV vaccination in boysMonth 12, 24 and 36Proportion seroconverting to, and geometric mean antibody titres (GMTs) for, HPV vaccine genotypes, and safety and tolerability (local and systemic adverse events), measured in a subset of 200 vaccinated boys
Impact of female-only vaccination through the national vaccination programme on population HPV prevalence in 18 to 21-year-old males and femalesMonth 36The proportion of females, and of males, aged 18 to 21 years in the control arm with detectable genital 4-valent HPV vaccine genotype DNA at baseline and at M36.
Uptake of dose 1 and coverage of dose 2 in eligible target groups for the national HPV vaccination programme;Month 36The proportion of females aged 16 years who received 1 dose of HPV vaccine (uptake) and who complete 2 doses (coverage) by arm at baseline and M36
Acceptability of a gender-neutral approach to HPV vaccinationMonth 24Self-reported acceptability of and barriers to receiving male vaccination by community members and to delivering male HPV vaccination by health care workers (HCW)

Countries

Tanzania

Contacts

CONTACTDeborah Watson-Jones, MD, PhD
deborah.watson-jones@lshtm.ac.uk

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Sep 9, 2026