A meta-analysis of 60 million individuals in high-income countries has identified significant decreases in HPV infections, anogenital wart diagnoses and precancerous cervical lesions (CIN2+) over eight-to-nine years after HPV vaccination.
The new study, published in The Lancet, is the first to show pooled estimates of the population-level impact of HPV vaccination on CIN2+ from several countries, the benefit of vaccinating more than one age group, and substantial herd effects in countries achieving high vaccination coverage.
The systemic review and meta-analysis included 65 articles in 14 high-income countries – 23 for HPV infection, 29 for anogenital warts and 13 for CIN2+ lesions.
A decrease of 83 per cent of HPV 16 and 18 in girls aged 13-19 years and, 66 per cent in women aged 20-24 years, five to eight years after vaccination, was noted. An overall 54 per cent reduction was also seen in HPV 31, 33 and 45 in girls aged 13-19 years.
Five to nine years after vaccination CIN2+ decreased significantly: 51 per cent reduction in screened girls aged 15-19 years and a 31 per cent reduction in screened women aged 20-24 years.
There were also significant reductions (up to 88%) in anogenital wart diagnoses in both males and females.