A prospective cohort study comparing efficacy of 1 dose of quadrivalent human papillomavirus vaccine to 2 and 3 doses at an average follow up of 12 years postvaccination

Scientists from the International Agency for Research on Cancer (IARC) and partner institutions have demonstrated that the protection offered by a single dose of quadrivalent vaccine against persistent infection with human papillomavirus (HPV) types 16 and 18 – the HPV types responsible for nearly 80% of cervical cancers in low- and middle-income countries – is as high as that offered by two doses or three doses of the vaccine even 15 years after the first dose of the vaccine was administered. The new report is part of a special issue of the Journal of the National Cancer Institute Monographs, published to coincide with the 36th International Papillomavirus Conference (IPVC), which is taking place in Edinburgh, United Kingdom, on 12–15 November 2024.

The research team is conducting long-term follow-up of a cohort of about 17 000 female participants in India who received three or two doses or a single dose of the quadrivalent HPV vaccine at age 10–18 years in 2009–2010. The vaccine efficacy of a single dose against persistent infection with HPV16 and 18 was found to be 92.0%, which was not significantly different from the efficacy of two doses or three doses of the vaccine. No high-grade cervical precancer associated with HPV16 and 18 was detected among vaccinated participants.

This study demonstrates the high efficacy of a single dose, as well as how vaccination will reduce HPV positivity rates and requirements for colposcopy within cervical screening programmes in real-life settings. The durable protection offered by a single dose 15 years after vaccination and the cost savings associated with lower HPV positivity rates and lower requirements for colposcopy and treatment as the vaccinated women undergo screening will support the decision of the 58 countries that already use a single dose in their HPV vaccination programmes and encourage other countries to do so.

Malvi SG, Esmy PO, Muwonge R, Joshi S, Poli URR, Lucas E, et al.
A prospective cohort study comparing efficacy of 1 dose of quadrivalent human papillomavirus vaccine to 2 and 3 doses at an average follow up of 12 years postvaccination
J Natl Cancer Inst Monogr. Published online 12 November 2024;
https://doi.org/10.1093/jncimonographs/lgae042

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