Abstract
BACKGROUND: In 2020, the World Health Organization (WHO) declared a global strategy to accelerate the elimination of cervical cancer as a public health problem, for which high vaccination coverage rates are a key component. Since its inception in 2008, the UK national adolescent human papillomavirus (HPV) vaccination program has changed the vaccines being offered, the dosing regimen, and has become gender neutral. METHODS: We conducted serosurveillance to evaluate the magnitude and durability of vaccine-induced humoral immunity across various schedule changes, including changing from the bivalent to the quadrivalent vaccine, changes from a 3-dose to 2-dose schedule and inclusion of boys. It does not yet cover more recent schedule changes that include the nonavalent vaccine. Serostatus and antibody levels (in IU/mL) are reported for all nonavalent vaccine types. RESULTS: Our findings are consistent with data from clinical trials supporting durability of high vaccine-induced antibody levels through to adulthood (into the peak ages of exposure to sexually transmitted infections) and comparability between males and females. CONCLUSIONS: These data support the utility of serosurveillance to monitor population level immunity to inform and evaluate national HPV vaccination programs. This ongoing serosurveillance aims to identify any reductions in vaccine-induced immunity that could foretell of a potential weakening in HPV control.