# IARC India HPV vaccine dose study (one, two or three doses)

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

## TL;DR

When an Indian vaccine trial was halted midway, thousands of girls had had only one shot; following them for ten years showed one dose protected as well as three, changing the world's vaccination policy.

## Summary

The study began as a randomised comparison of two versus three doses of quadrivalent HPV vaccine at nine Indian centres. Recruitment was suspended in 2010 by the government, leaving by-default cohorts of girls who had received one dose (4,949), two doses (4,980) or three doses (4,348). At a median follow-up of 9.0 years, vaccine efficacy against persistent HPV 16/18 infection was 95.4% (95% CI 85.0-99.9) after one dose, 93.1% (77.3-99.8) after two and 93.3% (77.5-99.7) after three, and one-dose antibody levels, though lower, were stable. With the KEN SHE randomised trial in Kenya, these results led WHO in 2022 to endorse one- or two-dose schedules, roughly halving the cost of protecting a girl.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-10
- Phase: observational
- Setting: Girls aged 10-18 in India randomised to two or three doses of quadrivalent HPV vaccine; after a 2010 suspension of recruitment, cohorts who had received one, two or three doses were followed for a decade
- Sponsor: IARC with nine Indian centres
- Enrolled: 17729
- Result: Efficacy against persistent HPV 16/18 infection: 95.4% (1 dose), 93.1% (2 doses), 93.3% (3 doses) at 10 years.
- Outcomes: Vaccine efficacy against persistent HPV 16/18 infection: One dose 95.4% vs Two doses 93.1% vs Three doses 93.3%
- Replication: KEN SHE (Kenya, randomised) showed 97.5% single-dose efficacy against persistent HPV 16/18 infection; WHO endorsed one- or two-dose schedules in 2022.

## Sources

- Basu et al., Lancet Oncology 2021: https://doi.org/10.1016/S1470-2045(21)00453-8
- Sankaranarayanan et al., Lancet Oncology 2016: https://doi.org/10.1016/S1470-2045(15)00414-3

## Connected records

- 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/)
- cancers: [Cervical cancer](https://onco.cc/cancers/cervical/)
- technologies: [HPV & HBV vaccination](https://onco.cc/technologies/hpv-vaccine/)
- drugs: [CERVAVAC (quadrivalent HPV vaccine, India)](https://onco.cc/drugs/cervavac/), [Nonavalent HPV vaccine](https://onco.cc/drugs/gardasil-9/)
- institutions: [Cancer Institute (WIA), Adyar](https://onco.cc/institutions/cancer-institute-adyar/), [International Agency for Research on Cancer (IARC / WHO)](https://onco.cc/institutions/iarc/), [Tata Memorial Centre](https://onco.cc/institutions/tata-memorial/)
- trials: [KEN SHE (single-dose HPV vaccine)](https://onco.cc/trials/ken-she/)
- people: [Partha Basu](https://onco.cc/people/basu-partha/), [Rengaswamy Sankaranarayanan](https://onco.cc/people/sankaranarayanan-rengaswamy/)
- bottlenecks: [Most of the world has almost no cancer care](https://onco.cc/bottlenecks/b-global-access/), [Prevention we already have is not deployed](https://onco.cc/bottlenecks/b-prevention-adoption/), [Wrong doses](https://onco.cc/bottlenecks/b-dose-optimisation/)
- key papers: [Immunogenicity and HPV infection after one, two, and three doses of quadrivalent HPV vaccine in girls in India: a multicentre prospective cohort study](https://onco.cc/key-papers/paper-sankaranarayanan-lancet-oncol/), [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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