New Vaccine Traps Malaria In Blood Cells

An experimental vaccine for malaria is taking a novel approach to defeat the disease. Animal testing has revealed that the vaccine can successfully protect a patient from malaria by trapping the responsible parasite in the very red blood cells that it infects - preventing it from reproducing and spreading throughout the body.

A study published in the journal Science details how researchers identified and then targeted the protein PfSEA-1, which reportedly allows the malaria parasite to escape the red blood cells they infect.

According to the US Centers for Disease Control and Prevention (CDC), the malaria parasite life cycle normally involves a complex reproductive process. In humans, the parasites infect red blood cells where they mature and multiply. They then break out of the infected cells to infect more cells until they become largely prevalent in the body.  

This blood-stage of reproduction causes the symptoms of malaria, which can be mild and unnoticeable or severe and deadly. The worst symptoms often result from rampant destruction of red blood cells, causing severe anemia, cardiovascular collapse and acute kidney failure, according to the CDC.

However, scientists think they can use these stages against the parasites.

"Since the malaria parasite has such a complex replication cycle, there are multiple points in that replication cycle that are vulnerable to interference by an antibody or some response that can be induced by a vaccine," researcher Michal Fauci, of the US National Institutes of Health, told Reuters.

According to the study, after Fauci and his colleagues identified the protein PfSEA-1 as the key to the parasite's ability to escape red blood cells, they looked for a way to take that key away. If the parasites remain trapped, the authors write, they can be destroyed in the spleen.

To develop a vaccine that suppresses this protein, researchers started by inoculating lab mice in a series of trials.

In five trials, the vaccinated mice exposed to malaria showed parasite levels four times lower than control mice. These vaccinated mice also survived significantly longer.

According to Reuters, following these encouraging initial tests, the researchers will be moving on to test the vaccination in monkeys - hoping to have started clinical trials for people in less than two years.

The study was published in Science for May 23.