The Malaria Vaccine Is A Big Deal, but Not a Silver Bullet

Pag Patrick Duffy beginning his career at the Walter Reed Army Institute of Research in 1991, scientists have spent several years testing a first -class vaccine that can protect against malaria. Thirty years ago, the World Health Organization had finally recommended the product of that research as a malaria intervention for children under the age of 5 in Africa. The RTS, S vaccine, also called Mosquirix, was the first vaccine to protect against a parasite.

Duffy, now chief of the Laboratory of Malaria Immunology and Vaccinology at the National Institute of Allergy and Infectious Diseases, is excited about the potential to reduce the number of diseases that kill more than 400,000 people each year. But he is well aware that this vaccine is not a solution at all. “It prevents clinical malaria in children,” he said. Although it does not stop transmitting the parasite from mosquitoes to humans, and it does not protect everyone who is vulnerable. “What about pregnant women? What about elimination? ”He asked. “I feel like it’s a standard on which it can be improved.”

Scientists at the pharmaceutical company GlaxoSmithKline (GSK) first conceived RTS, S in 1980, targeting children under 5, with an overdose account. 65 percent of malaria deaths. People develop resistance to the parasite at their age, so adults are not as seriously ill as children when infected. This vaccine is intended to speed up that process, providing protection to children until their resistance is stronger.

But the vaccine has been tested for a long time. GSK has partnered with organizations including Walter Reed, the Bill and Melinda Gates Foundation, and clinics in seven African countries to run clinical trials. The European Medicines Agency evaluated the vaccine as safe and effective after Phase III clinical trials conducted by GSK from 2009 to 2011 found it 50 percent effective in preventing severe disease. However WHO officials are also not yet convinced that it will work in a global context, as the vaccine requires four doses, to be shipped as shots, over 18 months. That’s why GSK is running an additional pilot program in 2019, testing the product in Ghana, Kenya, and Malawi.

Even if health ministers in each country have to approve the vaccine, a WHO recommendation is a huge endorsement. But growing production to produce millions of doses, organizing national health systems to distribute them, and getting financial help from nonprofits and other countries takes time. “There’s still a lot of work to be done before the vaccine can be used more widely,” said Ashley Birkett, director of the malaria vaccine initiative at PATH, a nonprofit that helped develop the vaccine.

Malaria is a complex parasite that has been evolving with humans for thousands of years. Unlike respiratory viruses like the flu that spread through the air, malaria spread by mosquitoes. They take the parasite from the blood of infected people, and then bite others in the community, passing the parasite through them. While the SARS-CoV-2 virus has about 10 genes that code for 29 proteins, Plasmodium falciparum, one of the five parasites that cause malaria, has a much larger genome that encodes more than 5,000 proteins.

The parasite also has a complex life cycle. When a mosquito bite bites a person, small spores called sporozoites enter the bloodstream and travel to the liver, where they begin to multiply by dividing themselves. Those travel from the liver and into the heart, lungs, and bloodstream, where they can infect red blood cells and begin to afflict people with symptoms such as the flu, nausea, and tremors. In severe cases, malaria can cause brain damage, seizures, difficulty breathing, and organ failure.

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