CLINICAL QUESTION

How effective is the bivalent human papillomavirus (HPV) vaccine in preventing invasive cervical cancer?

BOTTOM LINE

The data are convincing that the HPV vaccine is effective in preventing invasive cervical cancer, especially when given to those who are 12 to 13 years of age. Partial immunization in older children was potentially ineffective. The study evaluated the real-world effectiveness of the bivalent vaccine that has largely been replaced by nonavalent HPV vaccines. The vaccine had the greatest effectiveness among women living in the lowest socioeconomic strata. (Level of Evidence = 2b)

SYNOPSIS

The researchers linked several information sources from Scotland, including the National Health Service Scotland, the Scottish Cervical Cancer Call Recall System, and the Scottish Cancer Registry. The authors used postal codes to determine the Scottish Index of Multiple Deprivation, which includes income, employment, education, health, access to services, crime, and housing data. From these sources, they determined the number of HPV vaccine doses received, the age of administration, and the rates of cervical carcinoma. They included women born between 1988 and 1996 and used July 2020 cancer data. The researchers analyzed data on 447,845 women; 239 had developed invasive cervical cancer. They identified no cases of invasive cervical cancer in adults who received any doses of the HPV vaccine at 12 to 13 years of age. Very few (411) girls 12 to 13 years of age were partially immunized. Partial immunization in children 14 years or older was ineffective. The unvaccinated women were primarily older women who did not receive catch-up immunizations. Although the cancer incidence was highest among women with the greatest deprivation index, the vaccinated women in this group had the greatest reduction in cervical cancer incidence. Table 1 summarizes the number of cases of invasive cervical cancer, the incidence rate per 100,000 women, and the vaccine effectiveness (adjusted for deprivation index).