Adopt new malaria vaccine, it's cheaper, say researchers

Researchers have advised Kenya to adopt the new malaria vaccine whose positive results were released last week.  

The vaccine was partly tested in Kenya and the results published last week showed it has an average of 78 per cent efficacy over 12 months.

Dr Damaris Matoke, the deputy director of Biotech Programme at the Kenya Medical Research Insitute, said R21 will complement the existing vaccine, which is already being used in Western Kenya.

“As researchers, we strongly recommend the country to adopt it. It is definitely cheaper and will be a good addition to the existing vaccine.”

Dr Matoke said the two vaccines have to be used alongside other prevention methods such as bed nets and vector control methods.

She spoke in Nairobi during a workshop by the Zero Malaria Campaign Coalition (ZMCC), which brings together the Ministry of Health and other key partners.

The coalition is planning a malaria campaign supported by Malaria No More UK (MNMUK), a team of experts in communications and advocacy based in London and Nairobi.

“Kenya has made great strides in fighting malaria and has a vision to be malaria-free by 2030. However, malaria still has a significant impact on its citizens,” Dr Matoke said.

“We are at a critical moment in the malaria fight with progress threatened by challenges in funding gaps, drug and insecticide resistance and climate change, among others.”

She said the greatest burden from malaria in Kenya is felt by children under five years and pregnant women.

Kenya has made strides in regaining progress following Covid-19 disruptions. Although not yet returned to pre-pandemic levels, malaria incidence and mortality decreased between 2021 and 2022 (WMR 2023).

The RTSS is the first vaccine recommended to prevent malaria in children.

It is delivered through routine immunisation programmes alongside other childhood vaccines in public and private health facilities in 25 subcounties in Western.

Initially, the vaccine schedule adopted in Kenya was three primary doses given to children at six, seven and nine months and a fourth dose at 24 months.

However, the Ministry of Health broadened the eligibility for the first dose to between six and less than 12 months of age, with the second and third doses at least one month apart. The fourth dose is administered from when a child is 24 months, with an upper age limit of three years.

Kenya has yet to adopt the R21 vaccine, although it is partly being tested in Kilifi.

Trial investigators last week reported on average 78 per cent vaccine efficacy over the first year of follow-up in Kilifi and four other sites in Burkina Faso, Mali and Tanzania, where tests are ongoing.

The results relate to children aged five to 17 months, the age range, which is studied for most malaria vaccines.

The full results of the phase III trial have been published in the Lancet journal.

“No other vaccine has reported over 55 per cent efficacy in the same age group,” said a statement from the researchers, who include Dr Mainga Hamaluba, the principal investigator in Kilifi.

Its 78 per cent efficacy means that if 100 children were vaccinated and exposed to the malaria parasite, approximately 78 of them would be protected from getting sick, while 22 might still contract malaria, despite being vaccinated.

The researchers also reported no serious adverse events linked to immunisation.

“R21/Matrix-M vaccine was well tolerated, with injection site pain and fever as the most frequent adverse events,” they said.

“Number of adverse events of special interest and serious adverse events did not significantly differ between the vaccine groups. There were no treatment-related deaths.”

In Kilifi, 600 children were involved in the study, but overall, more than 4,800 young children took part in the trial in the four countries.

The Ministry of Health estimates that approximately 4,000 people in Kenya die from malaria every year, most of them being children.

The R21 was approved by the World Health Organization in December last year.

R21 was designed in 2011 as a potential improvement on the RTSS vaccine designed in the 1980s.

It was developed by the Oxford University of the UK, but will be manufactured by The Serum Institute of India (SII), the university said in a statement.

Prof Adrian Hill, chief investigator of the entire trial, said, “The continued high efficacy of this new vaccine in field trials is very encouraging and consistent with the high efficacy and excellent durability observed in a smaller four-year phase IIb trial.”