World Malaria Day - fighting maternal malaria
PhD student Sisse Bolm Ditlev is working on a vaccine that can protect pregnant women from maternal malaria
At the Centre for Medical Parasitology, the VAR2CSA-team is working on a vaccine against pregnancy related malaria. The team is named after the protein, which binds the malaria parasite to a woman’s placenta and this protein is the key to developing the vaccine. We asked PhD-student Sisse Bolm Ditlev about her research and how close the team is to having the vaccine ready.
What is pregnancy related malaria?
During pregnancy women builds up a placenta to support fetal growth. The Plasmodium falciparum malaria parasite has evolved to specifically hide from the immune system in the woman’s placenta. The parasite does this by transporting a protein to the surface of the infected red blood cell. The protein is named VAR2CSA and it specifically and exclusively binds to a receptor only present in the placenta named chondroitin sulfate A (CSA). Thereby the parasite avoids being circulated in the bloodstream of the woman’s body which could lead to its destruction in the spleen.
What are the risks associated with this kind of malaria?
Placental malaria is a major cause of severe maternal anemia and deaths, abortion, stillbirth and delivery of low-birth-weight babies in malaria endemic areas. It is estimated that 10,000 of these women and 200,000 of their infants die each year are a result of malaria during pregnancy. First- and second-time pregnant women are most seriously affected. Researchers believe this is due to a repertoire of antibodies against the parasite adhesion protein has been built up in the women after several pregnancies .
How can pregnant women today prevent themselves from getting this kind of malaria?
Some of the clinical symptoms during placental malaria can be prevented through the use of intermittent preventive treatment with the drug Fansidar which is an intervention for effectively preventing and controlling malaria during pregnancy. Another very important approach is to sleep under insecticide-treated nets. Using drugs and bed nets is an important strategy for protecting pregnant women and their newborns from malaria-carrying mosquitoes, the main problem is that the women do not have access to or cannot afford bed nets or the treatment.
How far are we from having a vaccine ready?
In 2003 our research group in Copenhagen identified the protein, VAR2CSA, which makes the parasite infected blood cells stick to the placenta. VAR2CSA is the vaccine candidate we use as a model for the vaccine development. We have now defined a region of the VAR2CSA protein that seems to be responsible for the parasite binding to the placenta. Our aim is to make a vaccine that will induce antibodies that prevents the parasites from binding and thereby the infected red blood cells will be filtered by the spleen. By now, we are optimizing the minimum binding region of the VAR2CSA protein to go into clinical trial that are planned to start within 4 years.
Why do you work with this research area - why do you find it important?
Malaria during pregnancy is double trouble since it both affect the mother and the unborn child and a vaccine against placenta malaria seem feasible since women acquires protective antibodies during subsequent pregnancies. Although malaria is preventable and curable many lives are wasted, also due to resistance to malaria medicine. A vaccine can hopefully be cheap, safe and stable in the field and induce long-lasting protection with a global coverage. The women that now uses too much time on being ill and taking care of their ill offspring will have better opportunities to build a better life.