A single dose of the human papillomavirus (HPV) vaccine may be the key to eliminating cervical cancer for good, according to new research published by the World Health Organization (WHO) on Monday.
Human papillomavirus, more commonly known as HPV, is a sexually transmitted infection (STI) responsible for causing more than 95% of cervical cancer cases. Recent evidence evaluated by the WHO Strategic Advisory Group of Experts on Immunization (SAGE) showed that a single dose of the HPV vaccine provided “comparable efficacy to the two- or three-dose regimens,” according to a WHO news release.
There were an estimated 604,000 new cases of cervical cancer that caused 342,000 deaths in 2020 alone, according to the WHO. It has become the fourth most common cancer for women globally, especially in low- to middle-income countries, where 90% of all new cases were recorded in 2020.
This new finding could lead to a less costly and more efficient method of providing HPV and cervical cancer prevention for women and girls in low-income regions, such as Oceania and Africa, which account for 30.9% and 21.1% of global cases respectively.
“I firmly believe the elimination of cervical cancer is possible,” WHO Assistant Director-General Dr. Princess Nothemba Simelela said of the findings. “In 2020, the Cervical Cancer Elimination Initiative was launched to address several challenges, including the inequity in vaccine access. This single-dose recommendation has the potential to take us faster to our goal of having 90% of girls vaccinated by the age of 15 by 2030.”
The HPV vaccine was first introduced in 2006 and by 2018, the WHO announced that 100 countries had already integrated the vaccine into their national immunization schedules. Unfortunately, those 100 countries only covered about 30% of the global target population and uptake for immunization has been considerably slow, especially for low- to middle-income countries. By 2020, the number of countries had only reached 111.
The previously established regimen for administering the vaccine involved a two-dose schedule, which created difficulties in tracing and following up with recipients. A one-dose program would not only ease this challenge, but would also reduce costs and allow for resources and efforts to be redistributed toward other health directives.
Based on these new findings, SAGE has recommended an updated schedule for HPV vaccinations worldwide. The new recommendations would see a one- or two-dose schedule for the primary target of girls from ages 9 to 14, as well as young women from ages 15 to 20, with women over the age of 21 ideally receiving two doses within a six-month interval.
“SAGE urges all countries to introduce HPV vaccines and prioritize multi-age cohort catch up of missed and older cohorts of girls,” SAGE Chair Dr. Alejandro Cravioto said in a statement. “These recommendations will enable more girls and women to be vaccinated and thus [prevent] them from having cervical cancer and all its consequences over the course of their lifetimes.”
In 2020, the World Health Assembly adopted the WHO global strategy of eliminating cervical cancer as a public health problem by the end of the century. The plan includes a 90-70-90 target for 2030, which requires 90% of girls to be fully vaccinated against HPV by the age of 15, 70% of women screened by age 35 and again at 45, and 90% of women diagnosed with cervical cancer to receive treatment.
Less than 25% of low-income countries have introduced the HPV vaccine into their national schedules, compared to 85% of high-income ones. The mortality rate of cervical cancer is over 60% in low-income countries, compared to 30% in high-income countries.
“Most of these women are not diagnosed early enough and lack access to life-saving treatment,” WHO Director-General Dr. Tedros Adhanom Ghebreyesus said in 2018. “If we don’t act, deaths from cervical cancer will rise by almost 50% by 2040.”
HPV and cervical cancer are highly preventable with clinical trials showing the Gardasil vaccine to be nearly 100% effective in preventing infections and precancers caused by seven HPV strains, according to the National Cancer Institute.
Cervical cancer is referred to as “the silent killer” and has been called a “disease of inequity of access.” With the WHO's global strategy to eliminate cervical cancer, an estimated 63 million deaths could be avoided by 2120. And now, based on the new findings regarding single-dose efficacy, those projections could not only be increased — but at an accelerated pace.
“We need political commitment complemented with equitable pathways for the accessibility of the HPV vaccine,” Simelela said. “Failure to do so is an injustice to the generation of girls and young women who may be at risk of cervical cancer.”