# KEN SHE (single-dose HPV vaccine)

Source: https://onco.cc/trials/ken-she/  
OnCo record `ken-she` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

One shot of HPV vaccine was 97.5% effective against the two most dangerous HPV types, making it realistic to vaccinate the whole world.

## Summary

Vaccine efficacy 97.5% against persistent HPV16/18 infection at 18 months (NEJM Evidence 2022), sustained at 36 months. Together with the IARC India cohort and Costa Rica trial data, it underpinned the WHO 2022 recommendation for one- or two-dose schedules, adopted by more than 60 countries by 2025 and roughly doubling the number of girls a fixed vaccine supply can protect.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-07
- Registry id: NCT03675256
- Phase: 4
- Setting: Kenyan women aged 15-20: single dose of bivalent or nonavalent HPV vaccine vs meningococcal control, endpoint persistent HPV16/18 infection
- Sponsor: University of Washington / Bill & Melinda Gates Foundation
- Enrolled: 2275
- Result: Single-dose efficacy 97.5% against persistent HPV16/18.
- Outcomes: Vaccine efficacy against persistent HPV16/18 infection: Single dose nonavalent HPV 97.5%
- Replication: IARC India cohort (Basu 2021) and Costa Rica ESCUDDO/CVT data show similar single-dose protection.

## Sources

- ClinicalTrials.gov NCT03675256: https://clinicaltrials.gov/study/NCT03675256
- Single-dose evidence, Lancet Global Health 2024: https://www.thelancet.com/journals/langlo/article/PIIS2214-109X(24)00009-3/fulltext

## Connected records

- cancers: [Cervical cancer](https://onco.cc/cancers/cervical/), [Head and neck squamous cell carcinoma](https://onco.cc/cancers/head-and-neck/)
- technologies: [HPV & HBV vaccination](https://onco.cc/technologies/hpv-vaccine/)
- drugs: [Nonavalent HPV vaccine](https://onco.cc/drugs/gardasil-9/)
- people: [Ian Frazer](https://onco.cc/people/ian-frazer/)
- ideas: [Single-dose HPV vaccination plus HPV self-sampling to reach WHO elimination in low-income countries](https://onco.cc/ideas/idea-single-dose-hpv-self-sampling-elimination/)
- bottlenecks: [Prevention we already have is not deployed](https://onco.cc/bottlenecks/b-prevention-adoption/)
- trials: [IARC India HPV vaccine dose study (one, two or three doses)](https://onco.cc/trials/iarc-india-hpv-dose-study/)
- key papers: [Vaccine efficacy against persistent HPV 16/18 infection at 10 years after one, two and three doses of quadrivalent HPV vaccine in girls in India](https://onco.cc/key-papers/paper-basu-single-dose-hpv-lancet-oncol-2021/)
- roadmaps: [Cancer prevention roadmap: tobacco control and vaccines → biomarker-guided chemoprevention → interception in carriers](https://onco.cc/roadmaps/prevention-roadmap/), [Global access and affordability roadmap: essential medicines and generics → biosimilars and frugal trials → reliance, pooling and homegrown innovation](https://onco.cc/roadmaps/global-access-roadmap/)

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