WHO says just one dose of HPV vaccine protects against cervical cancer

The World Health Organization’s (WHO’s) Strategic Advisory Group of Experts on Immunization (SAGE) has said that a single dose of HPV vaccine is comparable to two or three doses in delivering solid protection against human papillomavirus (HPV) infections, for types 16 and 18 that cause 70% of cervical cancer cases.

Greater efforts need to be also made to counter the lack of knowledge about HPV and the cancers it causes, which is common across the globe.

If countries choose to adopt this new recommendation, it could potentially double the number of girls who can be reached with this critical life-saving vaccine. Cervical cancer, a growth of abnormal cells in the cervix which can lead to vaginal bleeding and pelvic pain, is one of the biggest killers of women – it claims the life of one woman every two minutes and killed 342,000 women in 2020, 90% of whom were in low- and middle-income countries. WHO has described this recommendation as a “game-changer”.

Urgent need to increase access

Despite the high burden of disease in these countries, and the availability of the HPV vaccine, girls have not had sufficient access to the vaccine for a number of reasons.

Yet access in low- and middle-income countries is vital: rates of cervical cancer screening are extremely low – across sub-Saharan Africa the uptake of screening is just 12%. This means that cancers will often be diagnosed far too late, making prevention the only way to reliably bring down rates of disease and death.

The HPV vaccine is also important in low- and middle-income countries as they also have the highest number of women with HIV. Women with HIV are six times more likely to develop cervical cancer than those without the disease.

Fewer doses needed, more girls vaccinated

Per the SAGE recommendation, the target age for the HPV vaccine is 9–14 years as this is before most girls will have any sexual encounters. The vaccine will protect them from HPV infection – a sexually-transmitted virus – before they do.

Most low- and middle-income countries have chosen a school-based delivery to reach girls, however not all girls in this age group in low- and middle-income countries have access to education. This is why some countries, like Kenya, have used a mix of vaccination strategies delivered through schools, health facilities and community outreach workers to reach girls.

These strategies mean a significant challenge so far has been reaching girls for their second dose six or 12 months later. The WHO global target for HPV vaccine uptake is 90%; in 2020 global coverage with two doses was only 13%.

Thus, the finding showing that one dose is enough for women up to the age of 21 years should both increase uptake as girls don’t have to return for a second or third dose, and ensure that there are more vaccine doses to go around.

Other barriers to pull down for better access

The cost of HPV vaccines has been a barrier for some countries in providing enough doses to their populations, though organisations like Gavi have ensured that the lowest-income countries can purchase the HPV vaccine for US $3-5.18 per dose.

Countries’ attempts to increase their HPV vaccine coverage has also been impacted by a shortage of doses. Though manufacturers are finding ways to ease supply constraints, the need for only one dose could significantly ease this pressure.

Greater efforts need to be also made to counter the lack of knowledge about HPV and the cancers it causes, which is common across the globe. For instance, a study in the US last year published in JAMA Pediatrics found that 60% of US men and 32% of women aged 18 to 26 did not know HPV causes cervical cancer. In addition to a lack of awareness of the HPV vaccine, vaccine hesitancy is also a factor in not wanting to take the vaccine.

Increasing uptake of the HPV vaccine will also require significant changes in awareness of cervical cancer and of the value of the vaccine in preventing it.