Kenyan women researchers release single cervical cancer vaccine

There is a silver lining in the fight against cervical cancer after a team of largely Kenyan women researchers released of a single shot vaccine.

The team after three years of research found that a single shot of Human Papillomavirus (HPV) vaccine is highly effective compared to the current three shot regime.

Cervical cancer is one of the leading causes of cancer deaths as nine women succumb to it daily in Kenya.

A randomized trial of the vaccine was done in Kenya from December 2018 to June 2021. It involved 2,275 women and adolescent girl aged between 15 and 20 years who were randomly assigned a therapy.

In three years of following the subjects, the researchers found that even if women tested positive for one strain of HPV, the vaccine protected them from other strains of the virus.

The study report was announced Wednesday during the International Papillomavirus Conference in Toronto, Canada.

“These findings are a game changer that may substantially reduce the incidence of HPV-attributable cervical cancer and positions single-dose HPV vaccination as a high-value and high-impact public health intervention that is within reach for us,” Kenya Medical Research Institute (KEMRI) Acting Director General, Prof Sam Kariuki, said after the announcement of the Kenya Single-dose HPV Efficacy (KEN SHE).

The study team comprised Kenyan researchers; Dr Nelly Mugo, Dr Maricianah Onono, Prof Elizabeth Bukusi and Dr Betty Njoroge.

Also in the team was Ruanne Barnabas, a Professor of global health at the University of Washington School Of Medicine who noted that “the single-dose efficacy was the same as multiple doses” and that the KEN-SHE trial could help the World Health Organization (WHO) reach its goal to have 90 percent of 15-year-old girls vaccinated against HPV by 2030.

If approved for use, the single-shot dose would simplify logistics and decrease costs.

Like many African countries, the Kenya HPV vaccine program rollout has faced the challenges of vaccine delivery, low uptake of the second HPV dose coupled with global HPV vaccine shortages.

“A single-dose HPV vaccination schedule could alleviate financial and logistical barriers that we currently face,” said Prof Kariuki adding that “KEMRI will work closely with the Ministry of Health and the researchers in the translation of these findings into action and ensuring that every girl and young woman gets this single shot.”

Human papillomavirus (HPV) is the most common viral infection of the reproductive tract and which affects both men and women who are sexually active.

To be eligible, participants had to be sexually active with less than five lifetime partners. They also had to be HIV-negative and without history of HPV vaccination.

 WHO notes that cervical cancer is the most common HPV-related disease, with nearly all cases of cervical cancer attributed to HPV infection.

Infection with certain HPV types also causes a proportion of cancers of the anus, vulva, vagina, penis and oropharynx, which are preventable using similar primary prevention strategies as those for cervical cancer.

Although most HPV infections clear up on their own and most pre-cancerous lesions resolve spontaneously, research has revealed that HPV infection may become chronic and pre-cancerous lesions that progress to invasive cervical cancer.

In Kenya, at least 33 out of 100,000 women have cervical cancer of which 49, 000 new cases were diagnosed in 2018 alone and 33,000 deaths reported.

President Uhuru Kenyatta in 2019 launched HPV vaccine uptake, a program that has faced challenges of vaccine delivery, low uptake of the second dose coupled with global HPV vaccine shortages. 

Pullout quote: If approved, the single-shot dose would simplify logistics and reduce costs