Tuesday, November 5, 2024

As promising malaria tools emerge, world’s biggest sufferer Nigeria lags

Despite having the worst malaria burden, Nigeria hasn't yet done enough to take advantage of promising new weapons against one of the world's deadliest killers.

On a rainy morning last July, Eka Enefiok woke up with a fever, and it was all too common. The food seller occasionally had fevers and headaches that would clear after she treated herself with traditional herbs or enemas. A few times, she would take over-the-counter tablets.

This time the fever was so severe she had chills and could not eat. At a nearby clinic in Ibesikpo-Asutan, Akwa Ibom state, a doctor diagnosed her with malaria – a disease so rampant in Nigeria it killed nearly 200,000 in 2021.

The doctor gave Enefiok medication and advised she be admitted, but her family, grappling with hardships, took days to act.

“There was no money, so we said we should look for money to go back within two days. She did not improve,” a family member told Pluboard, asking not to be named to discuss family issues.

Enefiok died the next morning. “It really broke us,” he said.

The World Health Organization (WHO) says malaria, which can be fatal within 24 hours of symptoms, killed 619,000 people in 2021. Nigeria accounted for 31.3% of those deaths — by far the highest in the world. Eighty percent of the fatalities were children under five.

Medical advances, including the use of improved drugs and treated mosquito nets, helped cut malaria deaths by half between 2000 and 2015, offering hope for eliminating the killer disease. Forty-three countries are currently malaria-free.

But the emergence of parasites resistant to drugs and preventive methods slowed the progress, made worse by the COVID-19 pandemic in 2020.

Now, using vaccines alongside other approaches is seen as a potential game-changer. And there are promising outcomes: WHO approved the world’s first malaria vaccine in 2021; Oxford University developed a second in 2022; and a monoclonal antibody therapy has shown promise.

Researchers have also genetically modified mosquitoes to make their offspring infertile, showing the possibility of getting rid of the malaria-spreading vector.

The findings open new possibilities for malaria-affected countries. However, despite having the highest disease burden, Nigeria has been slow in seizing those opportunities, compared to less affected African nations.

Nigeria opted out of a pilot trial of the first vaccine and missed out of the first round of delivery. Asked about the use of monoclonal antibodies as a malaria therapy as an example, one senior health official told Pluboard “Nigeria is not that advanced.”

“I am not aware of anything like that. Nigeria is not that advanced for that,” said the official at the federal ministry of health. He requested not to be identified since he was not authorised to speak on the matter.

Olugbenga Mokuolu, professor of molecular parasitology and genetics at the federal university, Oye Ekiti, said Nigeria needs to “look at new initiatives and also position ourselves in the vaccine game with respect to malaria.”

World Health Organization data shows Nigeria had by far more malaria deaths in 2021 Pluboard

The parasite called plasmodium

Malaria is caused by a parasite called plasmodium. When a person is bitten by a plasmodium-infected mosquito, the parasite travels through the bloodstream to the liver. After about 10 days without causing symptoms, it re-enters the bloodstream, attacks red blood cells, causing fever. Affected red blood cells could block blood vessels in severe cases.

Scientists failed to develop malaria vaccines mainly because plasmodium, a protozoan, has a complex life cycle. Unlike bacteria or virus, it develops both in mosquitoes and in humans, making it challenging to target one cell type before it invades another. Also, fighting it requires higher immune response.

Three notable options have now been developed in the last two years. All rely on antibodies – the proteins human bodies make to fight diseases – and target sporozoite, the first stage of plasmodium’s life cycle. While two stimulate the human body to generate antibodies, the third uses lab-created antibody, making it more targeted and powerful.

RTS,S (Mosquirix), developed by GlaxoSmithKline, uses protein from sporozoite to induce the production of antibodies that block plasmodium from liver cells. It reduced malaria by 30% to 40% in children.

Oxford University’s R21 uses a similar approach, but combines the sporozoite protein with a part of hepatitis B virus known to prompt a strong immune response. It adds a substance called Matrix-M to make it even more potent.

During a trial in Burkina Faso, R21 showed 77% efficacy. A widened trial involving 4,800 children in Burkina Faso, Kenya, Mali and Tanzania confirmed high levels of efficacy.

Monoclonal antibody therapy uses a type of immune cell to grow antibodies in the lab, with which it fights the invader by clinging to it. Developed at the U.S. National Institute of Allergy and Infectious Diseases, it showed about 88% efficacy at protecting adults in Mali.

“Monoclonal antibodies can contribute to morbidity and mortality reduction directly by offering high-level protection against infection or indirectly by preventing onward transmission,” Olusola Oresanya, Nigeria senior country technical coordinator at the UK-headquartered Malaria Consortium, told Pluboard.

“Given its potential to be delivered as a single dose that has a long term effect, it could be useful in areas of seasonal malaria transmission where the risk is high over 4-5 month.”

There are other advantages, says Jacqueline Kirchner, senior program officer at Bill & Melinda Gates Foundation.

“Unlike a vaccine, which relies on your body’s ability to mount a strong immune response and takes time to develop a high level of protective antibodies, a monoclonal antibody can provide protection almost immediately after injection and can work even in people with compromised immune systems,” said Kirchner, whose work focuses on developing monoclonal antibodies and other biologics for the prevention or treatment of infectious disease in low- and middle-income countries.

The first two options are less expensive and easier to administer than the last.

Malaria cases (blue) and deaths (red) in Nigeria and three other African countries. Credit: WHO; Pluboard

A slow response

Nigeria’s gains against malaria has slowed since 2015. The WHO said eight African countries were on track to meet the 2025 global target on malaria incidence reduction. Nigeria is not on the list that has Cabo Verde, Ethiopia, the Gambia, Ghana, Mauritania, Rwanda, South Africa, and Zimbabwe.

With the country facing its highest inflation in nearly two decades, and an excruciatingly high cost of living, more families like Enefiok’s struggle to pay for healthcare when they fall sick.

“We have instances where children, pregnant women and the elderly are left to die of malaria, which is treatable, because of lack of money and knowledge,” said Eno Edet, a pharmacologist at a government health facility in Akwa Ibom. The oil rich state is one of Nigeria’s wealthiest, yet has a high level of poverty at 71%, according to the National Bureau of Statistics.

New vaccines hold life-saving promise for many families in Nigeria, but the country has responded rather slowly to the opportunities.

Nigeria did not take part in the early trials of the three vaccines. The National Agency for Food and Drug Administration and Control (NAFDAC) said Nigeria did not consider 30% efficacy — which means three of 10 people protected – good enough.

“The RTS,S did not include Nigeria, because from the beginning the effectiveness was 30 percent, so we did not agree to join the clinical trial,” director general Mojisola Adeyeye told Channels TV in April. “For the R21, after reading the dossier, I believe Nigeria should join. This is because we have a high probability of success.”

Nigeria was excluded from the allocation of the first batch of 18 million doses of RTS,S because it did not meet the application deadline, according to GAVI, which supports the fight against malaria, HIV and other diseases in Africa. Twenty-eight countries expressed interest for the vaccines but 12 ultimately received. GAVI said Nigeria later applied, but vaccine supply will depend on the availability of the vaccines.

Nigeria also trailed Ghana in approving R21. When Pluboard contacted the drug regulatory agency NAFDAC in April after Ghana’s announcement, a top official said the agency was not aware Ghana had given early approval.

Within 24 hours of the inquiry, NAFDAC announced a “provisional approval” of R21, raising concerns about the thoroughness of its review. DG Adeyeye said the approval was given “after a very rigorous approval process”. Still, she said a clinical trial would be conducted in Nigeria.

The Nigerian Institute of Medical Research said Nigeria has now conducted its own pilot trial for RTS,S. Igbasi Uche, in charge of malaria implementation & applied research laboratory at the institute, told us: “What we are doing now is that the vaccine that has been produced – we want to try first. And currently, there is an ongoing trial of the vaccine.”

The health ministry official who spoke to Pluboard anonymously said by August neither RTS,S nor R21 was in the country, but that “the processes of making them available are still ongoing.”

A primary health care facility in Akwa Ibom, Nigeria. Credit: Uchenna Igwe/Premium Times

Doing it right

Oresanya of the Malaria Consortium said African nations need to do more independent research tailored to respond to their national malaria programme needs.

“National governments must also step in to ensure targeted research is prioritised and increased investment is available and better coordinated between countries, institutions and experts that will help to identify high-impact interventions and facilitate the adoption of cost-effective measures,” she said.


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