•The protective effect of this vaccine is short-lived, and it appears to depend on the intensity of transmission in different endemic areas.
• In children aged six to 12 weeks, the efficacy was estimated to begin at 63 per cent and waned to 11 per cent and 3 per cent after one and five years, respectively.
Image: COURTESY
The Ministry of Health is scaling up malaria vaccination using the RTSS jab to an additional 25 subcounties in western Kenya.
The expanded programme will be launched on Tuesday in Vihiga.
“We are thrilled to announce today that more children in Kenya will benefit from the life-saving protection offered by the world’s first malaria vaccine,” Health CS Susan Wafula said.
The ministry and its partners said they are scaling up because the World Health Organization in 2021 recommended the wider use of RTSS.
The expansion is funded through a Sh641 million grant the non-profit PATH received from the US-based Open Philanthropy. It was meant to support expansion of vaccine use in pilot areas in Kenya, Ghana, and Malawi through 2023, using vaccine doses donated by GSK, the manufacturer.
RTSS was introduced in Kenya in 2019 in 26 subcounties in Homa Bay, Kisumu, Migori, Siaya, Busia, Bungoma, Vihiga and Kakamega counties.
In the expanded programme, vaccination will begin in an additional 25 subcounties in these eight lake-endemic counties.
When the malaria vaccine was launched in Homa Bay county in 2019, the lake-endemic region had a malaria prevalence of 27 per cent, which has now dropped to 19 per cent according to data from the Kenya Malaria Indicator Survey (KMIS), organisations supporting the vaccine said.
They attributed this to the integrated malaria prevention strategies including utilisation of long-lasting insecticide treated nets and indoor residual spraying where available. Others are prompt diagnosis and treatment, and the malaria vaccine as an additional and complementary malaria prevention tool.
“Over the last three years, we’ve seen a dramatic reduction in the number of malaria cases and hospitalisation from malaria in areas where the vaccine has been administered. We are delighted to now be able to offer this additional malaria tool to more of our children,” CS Wafula said.
Since 2019, Kenya has vaccinated close to 400,000 children in the 26 subcounties.
Children under five years qualify for the vaccine and will get four doses from six months of age to the last dose at 24 months.
“In the coming years, our objective is to continue to expand malaria vaccination to other parts of the country as more supplies of the vaccine become available,” Dr Lucy Mecca, head of the National Vaccine and Immunization Programme, said.
WHO Country Representative Dr Abdourahmane Diallo said the pilot introduction of the vaccine to Kenya in 2019 resulted in a substantial reduction in deadly severe malaria, child hospitalisations and child deaths.
He said there is enough funding to support vaccination in all eight pilot counties.
“Additionally, GAVI has approved funding for malaria vaccine introduction into routine immunisation and will support the continuation of vaccination beyond the pilot period that will end this year,” Diallo said.
RTS,S/AS01 (RTS,S) acts against Plasmodium falciparum, the deadliest malaria parasite globally and the most prevalent in Africa.
The protective effect of this vaccine is shortlived, and it appears to depend on the intensity of transmission in different endemic areas.
An extensive phase III trial that included different endemic areas of Africa indicated that the efficacy against clinical malaria, a few weeks after the last immunisation, begins at 74 per cent in children aged five to 17. It decreases to 28 per cent and nine per cent after one and five years, respectively.
In children aged six to 12 weeks, efficacy was estimated to begin at 63 per cent and waned to 11 per cent and three per cent after one and five years, respectively.