Miguel Prudêncio's team - potential malaria protection vaccine


group photography
Credits: Prudenciolab


The Púbico newspaper brings us the good news! Two scientific articles on test vaccines have been published that have been shown to be safe in combating malaria.

One of these research groups is led by Miguel Prudêncio, Professor of Microbiology at FMUL and Group Leader at iMM João Lobo Antunes. In both research projects, “parasites were used for immunization and passed safety tests in the first phase of clinical trials. The results are encouraging, with the different strategies used to show signs of effectiveness in the tested volunteers, but it is still too early to say that the tough mission of finding a malaria vaccine will be successfully accomplished with these formulas. ”

Malaria was responsible for the deaths of 400,000 people in 2018.

“We showed that the vaccine was safe, that the volunteers tolerated immunizations well and did not show any relevant side effects”, Miguel Prudêncio tells Público newspaper.

Miguel Prudêncio's research team used a malaria parasite that does not cause disease in humans, only in rodents (plasmodiumberghei) and “masked it with an important protein from the version of the parasite that causes the most serious form of malaria in humans (the Plasmodiumfalciparum) ”. In this way, the "masked" parasite lodges in the liver and will not cause symptoms to the host. However, that parasite will carry with it an “important part of the version that causes the disease in humans, causing the necessary immune response to“ trigger ”.

This “genetically modified version of the Plasmodiumberghei parasite”, Miguel Prudêncio and his team nicknamed “PbVac” and has already been tested on 24 healthy human volunteers. “The group with the best results included 12 volunteers who received four sessions of 75 mosquito bites with this genetically modified parasite. Incredibly, immunization is done by subjecting participants to mosquito bites, which may seem strange, but which is common in malaria research projects. ”

The results have been positive, according to Miguel Prudêncio. “It reduced the amount of parasites in the liver and delayed the time it takes to get into the blood and, based on the formulas we have, we calculated that the impact it had on the parasite load was 95% in the immunized volunteers when compared with the individuals in the group control, not immunized ”.

The goal is to “make the leap from 95% to the“ perfect ”100% you want from a malaria vaccine”, but that will mean increasing “the dose administered to achieve a more robust effect and, eventually, adding some more proteins of the parasite that infects humans in the recipe ”. For this, it will be necessary to “subject participants to a violent session with more than a thousand mosquito bites, which is not even allowed and it is easy to see why”. In view of this impossibility, Miguel Prudêncio considers the injection hypothesis, which means that this injection should contain between “one thousand to three thousand mosquito bites for immunization with this disguised parasite”.

You can read this article in full here .