A single dose of human Papilloma Virus vaccine provides protection against cervical cancer

The Strategic Advisory Group of Experts (SAGE) on immunisation explained that evidence that has emerged in recent years shows that single-dose schedules of human Papilloma Virus (HPV) immunisation provide protection against cervical cancer comparable to two- or three-dose regimens.

HPV, which is sexually transmitted, causes more than 95% of cervical cancer, the fourth most common cancer among women in the world. 90% of women with cervical cancer live in low- and middle-income countries.

Cervical cancer is a preventable disease in almost all cases; however, many women suffer and succumb to it because of unequal access to health services, including vaccines, said experts from the World Health Organisation (WHO).

The chair of the Expert Group explained that the human papillomavirus vaccine is highly effective in preventing the serotypes responsible for 70% of cervical cancer.

"The Group urges all countries to introduce HPV vaccines and to prioritise immunisation of multiple age groups and older and missed girls," said Dr Alejando Cravioto.

The finding on the efficacy of single-dose vaccines would allow more girls and women to receive immunisation and be protected from cervical cancer and its consequences in their lives.

SAGE has repeatedly raised concerns about the slow pace of HPV vaccine introduction in immunisation programmes and the low overall population coverage, especially in the poorest countries.

WHO assistant director-general Nothemba Simelela expressed confidence that cervical cancer can be eliminated.

"In 2020, the Cervical Cancer Elimination Initiative was launched to address a number of challenges, including inequity in access to vaccines. This single-dose recommendation has the potential to move us faster towards our goal of 90% of girls being vaccinated by age 15 by 2030," she said.

Despite this confidence, Simelela clarified that vaccine uptake has been slow and that in-country coverage is much lower than the 90% target due to a number of factors, including supply challenges and costs associated with delivering a two-dose regimen to older girls who are not normally part of childhood immunisation programmes.

In addition, the cost of vaccines is relatively high, especially for middle-income countries. In 2020, global coverage reached just 13%.

In Dr Simelela's view, political commitment is needed for equity of access to immunisation.
The WHO stressed that the single-dose vaccine programme is less costly, requires fewer resources and is easier to administer.

It also facilitates the implementation of catch-up campaigns for multiple age groups, reduces challenges related to tracking girls for their second dose and allows financial and human resources to be redirected to other health priorities.

The UN agency said the adoption of single-dose schedules would turn cervical cancer prevention around as more doses would be available to reach more girls and save more lives.

Currently, the SAGE recommendation is to administer HPV immunisation as follows:

• a one- or two-dose schedule for the primary target of girls 9-14 years of age
• a one- or two-dose schedule for young women 15 to 20 years of age
• two doses six months apart for women over 21 years of age.

For women with compromised immunity, such as those who carry the human immunodeficiency virus, the Group recommends three doses where possible. If not available, they should receive at least two doses.