Game changers: Tinto, Muyembe, Wonkam…Pioneers of African health

This is part 2 of a 8-part series

Halidou Tinto: from one antimalarial to another

In the prevailing climate of all-out vaccination against Covid-19, this information almost went unnoticed yet it is no less crucial, even historic. On October 6, the World Health Organisation (WHO) recommended the widespread use of the malaria vaccine RTS,S/AS01 (RTS,S) in all malaria-affected regions of the world, starting with Africa.

For decades, Africa has been by far the most affected by this devastating disease. Of the 409,000 deaths recorded worldwide in 2019 by the WHO, 385,000 were in Africa. Among the deceased, more than 260,000 children were under the age of five. These are staggering figures, which have hardly decreased in recent years.

This means that this vaccine raises hopes in many African countries, especially those most affected (Nigeria, the DRC, Tanzania, Burkina Faso, Mozambique, Niger…). After the recommendation of the RTS,S vaccine, developed by the British pharmaceutical giant GSK through a pilot program still underway in Ghana, Kenya and Malawi, another vaccine could soon receive WHO approval: R21.

The latter is the result of 12 years of work by professor Halidou Tinto and his team at the Institut de Recherche en Sciences de la Santé in Nanoro, 90km northwest of Ouagadougou. After participating in research on the RTS,S vaccine between 2009 and 2014, this Burkinabe scientist partnered with Oxford University to design the R21 vaccine, which he describes as an “improvement on RTS”.

If we confirm the efficacy of this second vaccine after a year of phase III trials, we will have to apply for a temporary authorisation for use, as was done for the Covid-19 vaccines, for example.

During the second phase of the development of this new vaccine, trials were conducted on 450 children aged between 5 to 17 months in Nanoro, a town heavily affected by seasonal malaria. The results, published at the end of April in the scientific journal The Lancet, are very promising. They show that in children who received three doses over an eight-week period and received a booster one year later, R21 achieved an efficacy rate of 77%.

This makes it the most effective malaria vaccine to date, and exceeds the 75% efficacy goal set by the WHO for 2030.

Since May, R21 has entered phase III testing. For two years, it will be tested on 4,800 children in Kenya, Tanzania, Mali and Burkina Faso.

A financing mechanism must be created to facilitate the production and free distribution of RTS,S, though this probably will not happen before 2023. In any case, Tinto advocates for the rapid use of R21 if the tests prove conclusive.

“There is no time to lose in the fight against malaria,” he says. “If we confirm the efficacy of this second vaccine after a year of phase III trials, we will have to apply for a temporary authorisation for use, as was done for the Covid-19 vaccines, for example.”

Benjamin Roger

Muyembe-Tanfum takes on Ebola

A coronavirus? Nothing to worry about for Africans. They have always had to deal with malaria, HIV, tuberculosis, cholera and, worse, Ebola. In many countries of the continent, this was the first reaction in early 2020, when the WHO sounded the alarm about Covid-19.

The Ebola filovirus hemorrhagic fever, named after a river in the region, was first identified in 1976 in the village of Yambuku, within the north of what was then Zaire. Though it has killed an estimated 15,000 people since then, it is not the most deadly of the health scourges to hit the continent. The Covid-19 death toll in Africa has already reached 200,000.

Still, Ebola is frightening, and rightly so. The violence of its symptoms, the speed at which it spreads and the lack of effective medical treatment have made hemorrhagic fever a real nightmare. There are countless novels, films, series and even video games in which heroes confront this threat.

During the last decade, Guinea, Nigeria, Sierra Leone, Liberia and the DRC have had to deal with several epidemics, which could not be stopped for several months due to the lack of effective treatment.

Thus the announcement made on 17 September 2021 in Kinshasa by virologist Jean-Jacques Muyembe-Tanfum, director of the DRC’s Institut National de Recherche Biomédicale, was like a thunderclap. The Congolese researcher officially announced that Ebanga, an effective Ebola treatment developed in collaboration with American researchers, was arriving in hospitals.

“I am the happiest of the Congolese,” the professor said. “For 40 years, I have been a witness and an actor in the fight against this terrifying and deadly disease, and today I can say: it is defeated, it is preventable and curable.”

The statement is no exaggeration. Muyembe, a graduate of Belgium’s Katholieke Universiteit Leuven, who returned to Zaire in 1973, has devoted his entire life to fighting Ebola. He was one of the discoverers of the virus in 1976 and has never ceased – whether at the Pasteur Institute in Dakar, with the Americans at the CDC or as an adviser to the WHO – to seek ways to prevent the spread of the virus, to save the sick and to develop an effective vaccine.

Now hailed by the world’s media as one of the world’s most influential scientists, the 79-year-old doctor was also chosen by President Felix Tshisekedi to lead the Congolese response to Covid-19, a disease against which the strategies invented to fight Ebola have been successfully employed.

Olivier Marbot

Ambroise Wonkam, the secrets of African DNA

 

To explain the interest of his project, Ambroise Wonkam uses the example of the two diseases he probably knows best – the ones that led him to this idea that may well revolutionise scientific research. The first, sickle cell disease, which causes the deformation or breakdown of red blood cells, is the most common recessive genetic disease (requiring the genetic contribution of both parents) in humans – and 80% of children born with this disease are African.

The Cameroonian professor, who teaches medical genetics at the University of Cape Town in South Africa, has also worked on deafness. In European populations, half of the cases are caused by a gene that does not explain any of the cases on the African continent. In knowledge of this, Ambroise Wonkam said: “Africa is the new frontier to go beyond to discover new genes and new variants.”

In a study published in early 2021 in the prestigious scientific journal Nature, the geneticist explained that, of all the DNA sequenced in the world, only 2% of the human genomes analysed correspond to those of African people. “Yet,” he says, “Africa, the cradle of humanity, contains more genetic diversity than any other continent. Though knowledge and applications of genomics have not taken advantage of this, due to inequalities in healthcare systems, the weaknesses of local research teams and the lack of funding.”

Our project is certainly a human odyssey, but it is also a scientific imperative for humanity, because it will make it possible to truly address the issue of equity in the world.

By sequencing some three million Africans, Wonkam therefore hopes to restore equality in the treatment of the continent’s patients. He also intends to “rebalance the understanding of genetic medicine” and contribute to the advancement of global health and research through the “Three Million African Genomes (3MAG)” project, which grew out of his own work on how genetic mutations in Africans contribute to certain diseases.

The president of the African Society of Human Genetics is pleased to see the impact that what started as a “crazy idea” has had. Since the Nature article was published, he has had many meetings with health professionals, the genetics industry, the scientific community, research organisations and donors. Wonkam attended a meeting with the African Centre for Disease Control and Prevention in mid-November, after presenting his project to the WHO’s scientific committee a few weeks earlier.

According to the specialist, the cost of sequencing and storing a genome is “at least” $1,500 per genome, which means nearly $4bn for the entire project, which would be spread out over 10 years. An action of this magnitude would necessarily involve the support of the continent’s governments and increased cooperation between the scientists of the countries concerned. Nonetheless, Wonkam is optimistic. “Our project is certainly a human odyssey, but it is also a scientific imperative for humanity, because it will make it possible to truly address the issue of equity in the world.”

Marième Soumaré