A vaccine for malaria has just passed its first clinical trial with human volunteers. The vaccine combines living malaria pathogens with antimalarial medications and granted volunteers 100% immunity to the parasite even after 10 weeks. The details are in a paper that was just published in the journal Nature.
Malaria is a deadly infection caused by Plasmodium parasites. The parasites are spread by mosquitoes, which act as vectors for the disease. Although malaria is rare in the United States, it killed 438,000 people globally in 2015. Most victims were children in poorer regions of Africa. There are treatments, including antimalarial medications, and survival is likely if the disease is treated in time. These treatments are often unavailable in certain parts of the world, however, and scientists have spent years working on potential vaccines. While there have been several candidate vaccines, none have seen widespread use and the most effective ones are still in clinical trials.
Researchers from the University of Tübingen have been working alongside a biotechnology company called Sanaria Inc. to develop a 100% effective malaria vaccine. The company provided malaria parasites to test their new vaccine, which has been named Sanaria® PfSPZ-CVac. Unlike other vaccines, this one uses fully viable, living malaria parasites but combines them with an antimalarial drug called chloroquine. The living pathogens prompt a strong immune system response but then the chloroquine kills them as they enter the bloodstream—preventing any damage or adverse effects. This is a safe way to provide patients with a long-lasting immunity to malaria. After passing animal trials, the drug was tested by scientists from the Institute of Tropical Medicine and the German Center for Infection Research.
The research team recruited 67 healthy adults who had never been exposed to malaria. The researchers administered the vaccine at varying doses and the best results were seen at the highest dose. This high dose provided 100% protection for at least 10 weeks and there were no adverse side effects. These early results are a good sign and the researchers will be moving on to larger clinical trials.
The Sanaria® PfSPZ-CVac vaccine shows great promise for preventing malaria and has just passed its first human trial. Larger clinical trials will need to be conducted before the vaccine becomes publicly available but it has the potential to save hundreds of thousands of lives a year.
Mordmüller et al. Sterile protection against human malaria by chemoattenuated PfSPZ vaccine. Nature (2017).