A single dose of the human papillomavirus (HPV) vaccine seems to be almost as good as two or three injections for preventing cervical pre-cancerous lesions
Source:
https://www.newscientist.com/article/2211506-just-one-dose-of-the-hpv-vaccine-may-be-enough-to-lower-cancer-rates/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home