Single-dose HPV vaccination is currently being tested as a public health intervention with high impact.

Researchers released positive news Nov. 17 at Toronto’s 34 the International Papillomavirus Conference.

A randomized controlled trial of 2,275 women in Kenya revealed that a single dose of the human papillomavirus (HPV) vaccine was highly effective. The current recommendation for women is three-doses.

The single dose vaccine was highly efficient at 18 months for HPV vaccination. The single-dose effectiveness was the same as multiple doses.”

Ruanne Barnabas, the principal investigator of the trial and professor of global health at the University of Washington School of Medicine

This news could greatly hasten the pace of vaccinations . It also brings new energy to the campaign to make cervical cancer the first cancer to be completely wiped out globally. According to a study published in March in Preventive Medicine that looked at HPV vaccination rates at 15%, only 15% of women are currently being vaccinated. The study was published alongside an action plan to eliminate the disease.

Barnabas declared that the KEN-SHE trial could contribute to achieving the goal of the World Health Organization of having 90% of 15-year-old girls immunized against HPV by 2030. She noted that a single dose vaccine could simplify logistics and reduce costs. The WHO is celebrating the first anniversary of its pledge to end cancer.

Prof. Sam Kariuki, Acting Director General of Kenya Medical Research Institute (KEMRI) He said that the findings could drastically lower the incidence of cervical cancer caused by HPV.

The Kenya HPV vaccine rollout, like many African countries, has encountered challenges with regard to vaccine delivery, low vaccine uptake, and worldwide HPV vaccine shortages.

In the trial, women 15 to 20 years old were randomly assigned a treatment and followed up from December 2018 to June 2021:

  • 760 people were treated with a bivalent vaccine which included two strains (16/18) of HPV (16/18). This accounts for 70 percent of all cases.
  • 758 received a nonavalent vaccine that covered seven strains of HPV (16/18/31/33/45/52/58), which represent 90% of cases;
  • 757 were vaccinated and can protect against meningococcal m.

After 18 months, the bivalent vaccine was 97.5% effective against HPV 16/18 and the nonavalent vaccine was 97.5 percent effective against HPV 16/18. The nonavalent vaccine was 89% effective against HPV 16/18/31/33/45/52/58. Even if a woman was positive for HPV the vaccine protected her from other strains.

The majority of participants (57 percent) were between 15-17 years old. The majority of participants reported one lifetime sexual partner (61%). To be eligible, participants had to be active in their sexual lives with at least five lifetime partners, be HIV-negative, and have no history of HPV vaccination.

Researchers say that more studies need to be conducted to determine how long the vaccine will last.

“This trial provides a fresh approach in the fight against cervical cancer. It brings great hope to the women living in countries like Kenya that are prone to the disease,” said Dr. Nelly Mugo, co-principal investigator on the study and the senior principal clinical research scientist with the Center for Clinical Research at the Kenya Medical Research Institute in Nairobi. She is also an associate professor of global health at the University of Washington.

Researchers believe the Kenyatta National Hospital in Nairobi was one of the main catalysts for the trial. They stated that they would like to see the ward empty.

“I believe that I will see cervical cancer eradicated in my lifetime,” said Dr. Maricianah Onono with KEMRI. “So, let us take this one shot for every woman!”

According to the WHO, most sexually active women and men are infected by HPV at some stage in their lives, and some will be repeatedly infected. Both genders are more likely to become infected soon after they become sexually active. While nine out of 10 HPV infections will clear themselves within two years, others lead to cancer of the reproductive system, particularly cervical cancer. HPV also can cause cancers of the vagina, cervix penis, vulva, and oropharyngeal cancer (throat tongue, and tonsils).

In the world, cervical cancer kills a women every two minutes, according to WHO Director General Dr. Tedros Ghebreyesus. Most of those deaths are in Africa, which bears 80% of the burden of cervical cancer according to the WHO.

This trial is 15 years since the U.S. Food and Drug Administration approved its first HPV vaccine. Merck manufactured Gardasil in 2006, which was able to prevent four HPV types (6/11/16/18). Since then, two other HPV vaccines have been introduced: Cervarix (which prevents HPV 16/18) was approved in 2009, and Gardasil-9, which prevents an additional five high-risk HPV types was approved in the year 2014. However, due to cost and the limited supply of vaccines the coverage has been limited in areas that have the highest incidence of cervical cancer.

Barnabas said that women have received multiple doses of HPV vaccine due to gaps in evidence and concerns over clinically significant differences.

The study was funded by the Bill & Melinda Gates Foundation. Researchers visited the KEMRI Center for Clinical Research, Thika, Kenya, and the KEMRI Center for Medical Research, Kisumu, Kenya. They also visited the University of Washington Mombasa Lab, Mombasa, Kenya. The International Clinical Research Center at Washington School of Medicine in Seattle.

Journal reference:

Barnabas, R.V. et. the. (2021). Single-dose effectiveness of HPV vaccine in young African women. preprint article.

Content Source:

Gemma Wilson

Gemma is a journalism graduate with keen interest in covering business news – specifically startups. She has as a keen eye for technologies and has predicted quite a few successful startups over the last couple of years.

Related Articles