Science Oasis in Africa Seeks Promising Malaria Vaccine – 05/09/2021 – Balance and Health

Science’s greatest hope of overcoming one of the diseases that most afflict poor regions of the planet comes from a country normally associated with poverty and political instability.

Without access to the sea and on the southern border of the Sahara, Burkina Faso in West Africa is consistently represented in the ranking of the ten least developed countries in the world. In the most recent edition of the UN Human Development Index in 2020, it was the seventh worst position among 189 nations polled.

In a country with a literacy rate of only 41%, an oasis developing the latest science was a key player in the release of the most promising malaria vaccine ever tested.

Preliminary results, published in UK magazine The Lancet, showed 77% effectiveness in vaccines given to 450 children in Burkina Faso. This is a higher rate than previous efforts, which was no more than 55%.

The study is led by the prestigious Oxford University and the little-known Clinical Research Unit (Crun), a research center in Nanoro, 90 km from the Burkinabe capital of Ouagadougou.

“This is undoubtedly the moment in science when the enthusiasm button is turned on and we feel like we are a few steps away from the end of our journey,” says Halidou Tinto, 52, head of research in the African country and director of the clinic , in an interview with Folha by email.

Despite the excitement, the long-awaited vaccine for a disease that reached 229 million people worldwide in 2019 and caused 409,000 deaths still has a good way to go.

The final phase before the immunizer is fully developed, called Phase 3, will begin soon and will be coordinated by Crun.

In four African countries, including Kenya, Mali and Tanzania, in addition to Burkina Faso itself, 4,800 children between the ages of 5 and 36 months are being given a dose of the experimental vaccine R21.

The idea is to test the immunizer under various transmission conditions, including places where it is persistent and more intense than in Burkina Faso, where the disease attacks six months a year. Only then will it be possible to see its real effectiveness.

According to Tinto’s calculations, Phase 3 should last 24 months, and if all goes well, a vaccine would be available in three or four years.

“I am personally confident because the R21 is not exactly new,” says Tinto. He explains that the vaccine tested is an improved version of RTS, S, until now the World Health Organization’s (WHO) main bet on fighting malaria.

However, the weakness of RTS, S is its low effectiveness, especially in children up to five years of age, a group that accounts for two-thirds of deaths.

Four doses are required for 40% protection, with less than 50% considered acceptable. This makes eradicating malaria very difficult.

R21 uses, as early antigens, proteins from the Plasmodium falciparum parasite that causes the mosquito-borne disease.

This provided a more effective response in antibody production than the previous version of RTS, S, which used hepatitis B proteins in 80% of its antigens.

According to Tinto, the other advantages of the current vaccine are that it is well tolerated by patients, has a good safety profile, and is easier to manufacture on a large scale.

There are still doubts as to whether the vaccine against variants of malaria will be effective in other parts of the world, including Brazil, as the tests were only done in Africa.

Children immunized in phase 3 of the study will be followed for two years. The tests are done on them precisely because they are the group most exposed to the disease.

For that, says Tinto, you have to work hard to convince the residents of the region, many of whom have little or no education.

It helps a lot that this is a clinic that has been set up for over ten years in the small town of around 40,000 residents and whose professionals are part of the daily life of the community.

“We have been working with the communities where the tests are taking place for a long time. There is an ongoing obligation to ensure that our research is well understood by families, ”he says.

The clinic’s history begins with funding from the Belgian government that Tinto received after completing his postdoctoral fellowship in parasitology at the University of Antwerp. The institute was founded in 2009 with support from the government of Burkina Faso and the Malarial Clinical Trials Alliance, an international initiative to discover the vaccine.

The aim was to be a reference in sub-Saharan Africa in the study of tropical diseases, with a particular focus on malaria.

Formally, the center is linked to the government of Burkina Faso, which accounts for a small part of its budget, but in practice operates independently.

Almost all funding comes from international partners, which include institutions affiliated with the European Union, philanthropic bodies such as the Wellcome Trust, and some pharmaceutical companies such as Novartis and GSK.

There are 274 professionals, including administrative and support staff, with a core of 24 dedicated solely to research. There are frequent exchanges with foreign scientists, mainly European and American.

The saga for a malaria vaccine is at least 50 years old, and the contrast with the Covid-19 immunizers made in less than a year is inevitable. For Tinto, this is due to two factors.

The first is the natural difficulty in developing vaccines against parasites, organisms that are much more complex than viruses. “The malaria parasite appears to be well adapted to the human host. This makes the immune response to malaria infection very weak and it is very difficult to develop an effective vaccine against it, ”says the director.

However, a large part of the delay is the lack of resources and the priority of the international community.

“Malaria clearly lacked the kind of investment in human expertise and resources that allowed the rapid development of the Covid-19 vaccine. Pharmaceutical companies are reluctant to invest in an area where returns are not guaranteed, let alone profits. “

He says serious efforts to fight the disease are less than 20 years old and that a milestone was the Bill and Melinda Gates Foundation’s decision to prioritize the issue in the early 2000s.

“Before that, it was considered impossible to talk about eradicating malaria,” he says. The prevailing opinion was that Africans would be sentenced to alleviate the disease by using only mosquito repellants and mosquito nets to sleep.

Now, says Tinto, this conformist view could be a thing of the past. “A very effective vaccine could turn the tide in the eradication of the disease”. We are a family business.

Leave a Reply

Your email address will not be published. Required fields are marked *