•The ‘KEN SHE study’ was conducted in Kenya among 2,275 women aged between 15 and 20 years over a 36-month study period
•During the study period, participants were regularly tested for HPV DNA, with cervical and vaginal swabs collected at regular intervals
Image: MoH
A single dose of the HPV vaccine is highly efficacious in preventing persistent infections of the virus over three years.
The research findings showed that the single dose of both the bivalent and nonavalent HPV vaccines had a 98 per cent efficacy.
The results of the study were released by researchers from the Kenya Medical Research Institute and Massachusetts General Hospital (MGH) during the 35th International Papillomavirus Conference in Washington DC last week.
The nonavalent vaccine showed a 96 per cent efficacy for the nine types of HPV it targets.
A bivalent vaccine works by stimulating an immune response against two different antigens while a nonavalent vaccine on the other hand works by stimulating an immune response against nine different antigens.
The ‘KEN SHE study’ was conducted in Kenya among 2,275 women aged between 15 and 20 years over a 36-month study period.
During the study period, participants were regularly tested for HPV DNA, with cervical and vaginal swabs collected at regular intervals.
"We believe that these findings could have significant implications for vaccination programmes in low-resource settings, where the burden of cervical cancer is highest," Kemri lead investigator Dr Nelly Mugo said.
Since December 2022, eight countries have announced they will switch to a one-dose HPV schedule which has traditionally required two to three doses following updated guidance from the World Health Organization.
The new research findings have significant implications for the prevention of cervical cancer, which is caused by persistent HPV infections.
“A single-dose vaccination schedule could simplify implementation and decrease costs associated with multi-dose vaccination schedules, making it a more feasible option for low-resource settings,” Kemri said in a statement.
Last month, the Ministry of Health announced that Boys in primary school will now be eligible to receive the free HPV vaccine, which prevents cervical cancer in women.
The human papillomavirus (HPV) vaccine is currently only given to girls, aged nine to 14 years.
The vaccination provides protection against HPV types 16 and 18 which are responsible for approximately 70 per cent of cervical cancer cases.
It protects them from HPV, the virus that causes almost all cases of cervical cancer in women.
"This study provides important evidence that a single dose of HPV vaccine can be highly effective in preventing persistent infections, and ultimately, cervical cancer," Dr Ruanne Barnabas said.
Barnabas is the lead investigator at Massachusetts General Hospital.
Kemri estimates that At present, only 33 per cent of the targeted population of girls are receiving the first HPV dose and 16 per cent returning for the 2nd dose in Kenya.
These low first-dose and even lower second-dose uptake rates are duplicated throughout Africa.
It is further estimated that of the 342,000 cervical cancer deaths reported in 2020, more than 90 per cent occurred in low- and middle-income countries.
A single-dose vaccination schedule could, therefore, go a long way in addressing this deadly inequity.