7 May 2019
A hugely positive study recently published in the British Medical Journal has indicated that a programme delivering the immunisation of 12-13-year-old girls has resulted in a dramatic reduction in cervical disease in vaccinated 20-year-old women found at screening. The study of 138,692 women attending for screening in Scotland showed a massive reduction (89%) in cervical intraepithelial neoplasia (CIN) at grade 3 or worse and accompanying reductions in the less severe pre-cancerous changes CIN2 (88%) and CIN1(79%). These results indicate that the policy of immunising girls at between 12 and 13 years of age has been highly effective in eradicating most strains of the human pappilomavirus (HPV) which is responsible for the majority of cases of cervical cancer.
Interestingly the vaccination was found to be less effective in a cohort of patients who were vaccinated aged 17 (51% effective) compared with those vaccinated routinely between 12 and 13 years (80%). This is thought to be because the vaccine is more effective on individuals who have not yet come in contact with the HPV virus.
Another positive effect of the vaccine was the high levels of ‘herd immunity’ with very significant reductions in CIN of all grades, even in women who have not been vaccinated. This is due to the very high uptake of the vaccination programme in Scotland with an overall reduction of the prevalence of HPV across the whole community.
Cervical cancer is the fourth most common cancer to affect woman world-wide and is a major cause of mortality in young women internationally. Screening programmes have been found to be effective in reducing cervical cancer mortality more developed countries but less so in lower or moderate-income countries. The researchers believe that ‘the development of vaccines against the most important oncogenic HPV types has the potential to be a major step in the prevention of cervical cancer’.
Julia Brotherton, the medical director of Australia’s National HPV Vaccination Program Register made a plea for HPV vaccinations to be made available across the whole world, to countries where they are not currently utilised or unacceptable, she said ‘we must work towards a world in which all girls and their families are offered, and the majority accept, HPV vaccination, wherever they live’.
The full study can be read here.