Oxford Covid-19 team to test new malaria vaccine in Kilifi

Team targeting 4,800 African children in Kilifi and in Burkina Faso, Tanzania and Mali

In Summary

• It will complement GSK's malaria vaccine, which is hugely popular but has safety concerns.

• It is going to be available in very large amounts, it works pretty well. And it’s going to be very low priced - Prof Adrian Hill

A child gets the RTS,S malaria vaccine during the clinical trials.
A child gets the RTS,S malaria vaccine during the clinical trials.
Image: FILE

Scientists behind the Oxford coronavirus vaccine being tested in Kilifi have said they will also test a new, cheap malaria vaccine in Kenya next year.

The team said their new malaria candidate will be tested on 4,800 children in Kilifi. It will also be tested in Burkina Faso, Tanzania and Mali, where malaria is endemic.

It could then be widely available for routine immunisation in 2024, should the late-stage trials be successful, said Prof Adrian Hill, head of Oxford University’s Jenner Institute, who are producing the vaccine.

“We've seen very promising results: good safety, good immune responses, and we're testing those vaccines now to see if they are effective in protecting children in Kilifi against malaria,” Hill said in an interview published by the university.

Last week, he told the Times (UK) newspaper that early-stage trials showed the vaccine works ‘pretty well’.

"It is going to be available in very large amounts, it works pretty well. And it’s going to be very low-priced,” he said.

The new vaccine works by inducing cells to destroy the malaria parasite inside the liver.

A 2015 trial among 121 adults in Kilifi, found it was 67 per cent effective in preventing malaria for eight weeks following the injection. But now the focus is on children.

Its licensing would be a major breakthrough because scientists have been unsuccessfully developing a malaria vaccine for 50 years now.

GSK is the only pharmaceutical company that got close, but its product has only about 30 per cent efficacy.

The GSK vaccine, called RTS,S, works by stimulating antibodies but has safety concerns and that is why the ongoing pilot in Kenya was ordered before licensing.

Dr Collins Tabu, head of Kenya’s National Vaccines and Immunisation Programme, says the RTS,S pilot is taking place in eight counties in western Kenya.

He said the demand is immense, and they have surpassed targets in certain regions.

The aim was to vaccinate about 120,000 children per year in Homa Bay, Kisumu, Migori, Siaya, Busia, Bungoma, Vihiga and Kakamega counties.

“As of August 2020, we’ve given at least 293,000 doses of the vaccine to children,” he told the World Health Organization in an interview.

“The demand has been so high, we’ve even seen an influx in some instances of individuals who are not from the vaccinating counties coming to ask for the vaccine,” he said.

RTS,S is given to children from six months of age.

Researchers are specifically assessing the feasibility of administering the recommended four doses of the vaccine in children and its effectiveness.

The biggest concern, however, is the vaccine's safety. During clinical trials between 2009 and 2014, children who received the RTS,S vaccine, also called Mosquirix, had a risk of meningitis 10 times higher than those who received a control vaccine.

In all cases, mortality also doubled in girls who received the vaccine.

Mosquirix may not have triggered the meningitis cases—there are other possible explanations—but the possible risk worried the global health community so much that, rather than rolling out the vaccine across Africa, the WHO decided to set up the ongoing pilot in Kenya, Malawi, and Ghana.

Convulsions after vaccination, though rare, also occurred more often in malaria vaccine recipients than in controls.