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Routine vaccination of girls aged 12–13 years with the bivalent human papillomavirus (HPV) vaccine in Scotland has resulted in a dramatic reduction in pre-invasive cervical disease, research published in The BMJ
has shown.
The research, which used data from 138,692 women born between 1 January 1988 and 5 June 1996 who had their smear test result recorded when they were aged 20 years, also revealed evidence of herd protection against high-grade cervical disease in unvaccinated women.
Compared with unvaccinated women born in 1988, the authors found that vaccinated women born in 1995 and 1996 showed an 89% reduction (from 0.59% to 0.06%) in prevalent cervical intraepithelial neoplasia (CIN) grade three or worse, an 88% reduction (from 1.44% to 0.17%) in CIN grade two or worse, and a 79% reduction (from 0.69% to 0.15%) in CIN grade one. The higher the CIN grade number, the higher the risk is of developing invasive cancer.
The University of Edinburgh research team also discovered that the vaccine was more effective in younger women. For example, the vaccine was 86% effective for CIN grade three or worse in women vaccinated aged 12–13 years compared to 51% for women vaccinated aged 17 years.
The authors said that the reduction in disease in routinely immunised women, who will form the bulk of the screened population in years to come, mandates revision of screening and referral guidelines.
“The findings emphasise the credibility of using high-risk HPV infection as an early marker of the effectiveness and success of the vaccine and underpin the recent call for global action on cervical cancer from the World Health Organization,” they said.
Scotland has an established national cervical screening programme and introduced its national HPV immunisation programme, along with the rest of the UK, in 2008. The programme was school based, targeting girls aged 12 and 13 years, supplemented with a three-year catch-up programme to the age of 18 years.
