{"entity":{"id":"iarc-india-hpv-dose-study","kind":"trial","name":"IARC India HPV vaccine dose study (one, two or three doses)","aka":[],"tldr":"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.","status":"positive","asOf":"2026-09-10","links":[{"label":"Basu et al., Lancet Oncology 2021","url":"https://doi.org/10.1016/S1470-2045(21)00453-8"},{"label":"Sankaranarayanan et al., Lancet Oncology 2016","url":"https://doi.org/10.1016/S1470-2045(15)00414-3"}],"tags":[],"related":["idea-single-dose-hpv-self-sampling-elimination"],"cancers":["cervical"],"sections":[],"technologies":["hpv-vaccine"],"targets":[],"drugs":["gardasil-9","cervavac"],"companies":[],"institutions":["iarc","cancer-institute-adyar","tata-memorial"],"pathways":[],"terms":[],"trials":["ken-she"],"people":["basu-partha","sankaranarayanan-rengaswamy"],"bottlenecks":["b-prevention-adoption","b-global-access","b-dose-optimisation"],"keyPapers":["paper-basu-single-dose-hpv-lancet-oncol-2021","paper-sankaranarayanan-lancet-oncol"],"journals":[],"dependsOn":[],"notes":[],"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","result":"Efficacy against persistent HPV 16/18 infection: 95.4% (1 dose), 93.1% (2 doses), 93.3% (3 doses) at 10 years.","yearReported":2021,"enrolled":17729,"enrolledBasis":"registry","outcomes":[{"endpoint":"Vaccine efficacy against persistent HPV 16/18 infection","primary":true,"unit":"%","arms":[{"name":"One dose","n":4949,"value":95.4,"note":"95% CI 85.0-99.9"},{"name":"Two doses","n":4980,"value":93.1,"note":"95% CI 77.3-99.8"},{"name":"Three doses","n":4348,"value":93.3,"note":"95% CI 77.5-99.7"}],"source":"https://doi.org/10.1016/S1470-2045(21)00453-8"}],"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."},"route":"/trials/iarc-india-hpv-dose-study/","neighbours":{"idea":[{"id":"idea-single-dose-hpv-self-sampling-elimination","kind":"idea","name":"Single-dose HPV vaccination plus HPV self-sampling to reach WHO elimination in low-income countries","route":"/ideas/idea-single-dose-hpv-self-sampling-elimination/"}],"cancer":[{"id":"cervical","kind":"cancer","name":"Cervical cancer","route":"/cancers/cervical/"}],"technology":[{"id":"hpv-vaccine","kind":"technology","name":"HPV & HBV vaccination","route":"/technologies/hpv-vaccine/"}],"drug":[{"id":"cervavac","kind":"drug","name":"CERVAVAC (quadrivalent HPV vaccine, India)","route":"/drugs/cervavac/"},{"id":"gardasil-9","kind":"drug","name":"Nonavalent HPV vaccine","route":"/drugs/gardasil-9/"}],"institution":[{"id":"cancer-institute-adyar","kind":"institution","name":"Cancer Institute (WIA), Adyar","route":"/institutions/cancer-institute-adyar/"},{"id":"iarc","kind":"institution","name":"International Agency for Research on Cancer (IARC / WHO)","route":"/institutions/iarc/"},{"id":"tata-memorial","kind":"institution","name":"Tata Memorial Centre","route":"/institutions/tata-memorial/"}],"trial":[{"id":"ken-she","kind":"trial","name":"KEN SHE (single-dose HPV vaccine)","route":"/trials/ken-she/"}],"person":[{"id":"basu-partha","kind":"person","name":"Partha Basu","route":"/people/basu-partha/"},{"id":"sankaranarayanan-rengaswamy","kind":"person","name":"Rengaswamy Sankaranarayanan","route":"/people/sankaranarayanan-rengaswamy/"}],"bottleneck":[{"id":"b-global-access","kind":"bottleneck","name":"Most of the world has almost no cancer care","route":"/bottlenecks/b-global-access/"},{"id":"b-prevention-adoption","kind":"bottleneck","name":"Prevention we already have is not deployed","route":"/bottlenecks/b-prevention-adoption/"},{"id":"b-dose-optimisation","kind":"bottleneck","name":"Wrong doses","route":"/bottlenecks/b-dose-optimisation/"}],"paper":[{"id":"paper-sankaranarayanan-lancet-oncol","kind":"paper","name":"Immunogenicity and HPV infection after one, two, and three doses of quadrivalent HPV vaccine in girls in India: a multicentre prospective cohort study","route":"/key-papers/paper-sankaranarayanan-lancet-oncol/"},{"id":"paper-basu-single-dose-hpv-lancet-oncol-2021","kind":"paper","name":"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","route":"/key-papers/paper-basu-single-dose-hpv-lancet-oncol-2021/"}],"roadmap":[{"id":"prevention-roadmap","kind":"roadmap","name":"Cancer prevention roadmap: tobacco control and vaccines → biomarker-guided chemoprevention → interception in carriers","route":"/roadmaps/prevention-roadmap/"},{"id":"global-access-roadmap","kind":"roadmap","name":"Global access and affordability roadmap: essential medicines and generics → biosimilars and frugal trials → reliance, pooling and homegrown innovation","route":"/roadmaps/global-access-roadmap/"}]}}