The World Health Organization has just approved the very first vaccine against malaria. It took decades.

After decades of failed experiments and mixed results, a malaria vaccine has gained World Health Organization approval. It is a much anticipated tool in the fight against a disease that kills hundreds of thousands of people each year, mostly young children in sub-Saharan Africa.

On Wednesday, WHO officials gave their approval to Mosquirix, which has been shown to be around 50 percent effective in preventing severe malaria in the first year of vaccination. The vaccine had been in development for 30 years, eventually achieving demonstrable success as countless other candidates ran out of steam. Health experts and clinicians had to face an absolute chore to get there.

And the efficacy rate underscores that the vaccine is far from perfect, Brian Grimberg, associate professor of pathology and international health at Case Western Reserve University, told The Daily Beast. He suspects that approval likely happened because progress against malaria has stalled in recent years.

“WHO says let’s try something because we’ve stalled,” Grimberg said.

Malaria is both preventable and curable, and the developed world remains fairly isolated from the worst. But in 2019 alone, there were still 299 million cases worldwide, according to the WHO. He also killed around 409,000 people that year. About 94 percent of these deaths have occurred in sub-Saharan Africa, where the disease is still rampant. More than half of these deaths occurred in children under the age of five.

Believe it or not, these dismal statistics are actually a improvement. In 2000, more than 700,000 people died from malaria. Tools such as insecticide-treated bednets (which reduce malaria deaths in children under five by about 20 percent) and antimalarial drugs have reduced that number to about 400,000. But those numbers haven’t changed much since 2015.

There is hope that the approval of a malaria vaccine now will revive progress.

It’s a wonder that Mosquirix even succeeded, given how difficult vaccines against malaria are to create. Malaria is caused by one of five different parasites, but the parasite that causes the most severe cases is called P. falciparum. It is spread when an infected mosquito (which has likely caught the parasite from an infected person) bites someone else, releasing the parasite into the bloodstream.

A parasite is “infinitely more complex” than a virus or bacteria – the types of pathogens that vaccines typically target, said Patrick Kachur, professor of population and family health at Columbia University Medical Center, in. Daily Beast. He also sits on the World Health Organization’s Malaria Policy Advisory Group.

P. falciparum has evolved alongside humans for most of our existence, so its genes are no stranger to adapting new ways to squeeze through the cracks of the human immune system. Grimberg noted that malaria parasites can enter a red blood cell in 22 different ways.

There are other obstacles facing malaria vaccines that have more to do with society than science. There are only about 2,000 cases of malaria in the United States each year, for example. It is a relatively low priority for rich countries. Kachur, who also sits on the WHO’s Malaria Policy Advisory Group, said it’s a constant challenge to get drug companies to invest in vaccine development for endemic countries. malaria, which are generally much poorer. Conducting scientific studies in African communities, where health resources are scarce, only exacerbates reluctance.

Mosquirix, made by drug maker GlaxoSmithKline, is the first malaria vaccine to overcome this long list of hurdles.

The vaccine consists of two main components: the first is a protein usually secreted by the P. falciparum when it is at an early stage. The second element is an adjuvant, a chemical booster that stimulates the immune system.

During a four-shot diet, the supercharged immune system learns to recognize the parasite’s business card. It is designed to intercept parasites during a key phase: when they are still floating in the bloodstream, but have not yet found refuge in the liver. This phase, says Grimberg, literally lasts minutes.

A phase III trial of more than 15,000 children and infants conducted over four years reported that the three main doses of the vaccine plus a booster were about 45 percent effective against severe malaria after one year. But that efficiency has plunged to around 36% in four years. Another smaller trial on 500 children showed a more dramatic decline. The vaccine’s effectiveness started at around 56% after the first year, but was close to zero after four years.

The most recent approval comes amid an ongoing pilot study in Ghana, Kenya and Malawi that has delivered vaccines to more than 800,000 children. It has reduced cases of severe and fatal malaria by 30 percent, according to the WHO.

In a world currently wrangling over COVID-19 vaccines with much higher efficacy, that fifty percent figure may seem low. It’s low, said Grimberg. And more importantly, Mosquirix has not been definitively proven to prevent fatalities. But there is some evidence that he can do it anyway, by fighting a serious illness. A 2020 study used mathematical modeling to estimate that, if distributed in countries with high malaria cases, it would prevent 23,000 deaths of children under five each year.

“After seeing so many children die of malaria, you try everything you can think of to save those children, and I think that’s what [WHO] look, ”said Grimberg.

It might also be appropriate to view this vaccine not as a replacement for drugs or insecticide-treated bednets, but as a supplement to them. “This extra effectiveness besides bed nets and on top of proper diagnosis and treatment when people get it, could save tens of thousands, if not hundreds of thousands of lives,” Kachur said.

Another silver lining, Kachur noted, is that while some hesitation about the vaccine may emerge, that hasn’t turned out to be a huge problem in this trial – suggesting that Mosquirix is ​​a vaccine that people will actually get. .

“Some media reports and organized groups have expressed hesitation about this,” he said. “None of the countries reported having had difficulty recruiting patients to come in for vaccinations in addition to their other childhood vaccinations.”

The next step in disseminating it to the world is to convince the Global Alliance for Vaccines and Immunizations, called GAVI, to help countries buy it in bulk.

There is still a long way to go to develop (and distribute) a vaccine against malaria. On the one hand, Grimberg believes an mRNA vaccine, like those used to fight Covid-19, might do a better job in the long run. “I think that’s probably where we’re going with this technology,” he said.

But it could be decades away. This vaccine already exists and it could possibly help save thousands of lives.