# 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

Source: https://onco.cc/key-papers/paper-basu-single-dose-hpv-lancet-oncol-2021/  
OnCo record `paper-basu-single-dose-hpv-lancet-oncol-2021` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Ten years after vaccination, Indian girls who had received a single dose of HPV vaccine were as well protected against the cancer-causing HPV types as those who had two or three doses, which let the world switch to one-dose programmes.

## Summary

Multicentre prospective cohort study arising from an IARC trial at nine Indian centres whose recruitment was suspended in 2010, leaving cohorts of girls aged 10 to 18 who had received one (4,949), two (4,980) or three (4,348) doses of quadrivalent HPV vaccine. At a median follow-up of 9.0 years (IQR 8.2-9.6), 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, compared with unvaccinated married women of similar age.

## Fields

- Kind: Key paper
- Last checked: 2026-09-10
- Journal: Lancet Oncology
- Year: 2021
- DOI: 10.1016/S1470-2045(21)00453-8
- Authors: Basu P, Malvi SG, Joshi S, et al.
- Findings: Single-dose efficacy against persistent HPV 16/18 infection 95.4% at a median of 9 years.; Two-dose 93.1% and three-dose 93.3%: no meaningful difference between schedules.; Antibody levels after one dose were lower but stable over time.; Cohorts were defined by default after the 2010 suspension, not by randomisation to one dose.
- What it means: One dose protects. WHO endorsed one- or two-dose schedules in 2022, halving the cost and the logistics of vaccinating girls, which is decisive for India (about 127,500 cervical cancers a year) and for the global elimination target. It also removed the main barrier to India's national programme with its home-made vaccine.
- Caveats: Non-randomised comparison of dose groups; confounding by who happened to receive fewer doses cannot be fully excluded.; Endpoint is persistent infection, not cervical cancer, although the link is well established.; Quadrivalent vaccine; nonavalent and bivalent products rely on separate evidence (KEN SHE, Costa Rica).

## Sources

- Lancet Oncology 2021: https://doi.org/10.1016/S1470-2045(21)00453-8

## Connected records

- 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: [International Agency for Research on Cancer (IARC / WHO)](https://onco.cc/institutions/iarc/)
- trials: [IARC India HPV vaccine dose study (one, two or three doses)](https://onco.cc/trials/iarc-india-hpv-dose-study/), [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: [Prevention we already have is not deployed](https://onco.cc/bottlenecks/b-prevention-adoption/), [Wrong doses](https://onco.cc/bottlenecks/b-dose-optimisation/)
- journals: [The Lancet Oncology](https://onco.cc/journals/lancet-oncology/)

---
JSON: https://onco.cc/api/v1/entities/paper-basu-single-dose-hpv-lancet-oncol-2021.json