Scientists have once again confirmed that vaccination against the human papillomavirus (HPV) reduces the risk of developing cervical cancer and some other tumors. Thus, among girls who were targeted by a vaccination campaign when they were 12-13 years old, the risk of cervical cancer decreased by 87%, and carcinoma in situ by 97%.
Scientists obtained such data by analyzing the results of the vaccination campaign in the UK. The full study was published in The Lancet.
Vaccination against human papillomavirus (HPV) is a critical component of the World Health Organization's plan to eliminate cervical cancer. HPV vaccines come in quadrivalent and bivalent varieties—against four and two strains of the virus, respectively. The latter make up 23% of the global market for such vaccines and work against strains that are responsible for 70-80% of cervical cancer cases.
Previous studies have shown that HPV vaccination may reduce the risk of cervical precancerous lesions in women who were not infected with the virus before vaccination. However, direct and high-quality evidence that vaccination directly prevents cervical cancer did not previously exist, the authors of this study indicate.
Human papillomavirus
Human papillomavirus is the most common cause of cervical cancer. HPV cannot be cured. Vaccination remains the only effective way to protect against infection.
Read the article
In a new study, scientists summarized the results of mass vaccination in the UK from 2006 to 2019. It was primarily aimed at girls aged 12-13 years. At the ages of 14-16 and 16-18 years, those who did not receive the vaccine earlier were additionally vaccinated.
“Early modeling suggested that the impact of the vaccination program on women aged 20-29 by 2019 would be significant. Our new study aimed to quantify that early impact,” said Professor Peter Sasieni from King's College London, co-author of the study.
During the period covered by the study, in the UK there were 28 thousand diagnoses of cervical cancer and 300 thousand — carcinoma in situ (when the tumor is very small — does not extend beyond the epithelium of the mucous membrane). The scientists calculated that vaccinated girls developed 450 and 17,200 fewer cases of these two types of tumors, respectively, than would have developed without vaccination.
Girls who were targeted by the vaccination campaign when they were 12-13 years old had an 87% reduced risk of cervical cancer and carcinoma in situ — by 97%. 89% of them received at least one dose of the vaccine, 85% were fully vaccinated with three doses.
Cervical cancer
Find out more about this tumor
Read the article
Among girls who received additional vaccination campaigns at the age of 14-18, the figures were more modest — their risk of cervical cancer decreased by 34-65%. There were significantly fewer fully vaccinated people in this group. In addition, with later vaccination, girls were at higher risk of contracting HPV.