Based on results from an early stage clinical trial, researchers at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, confirmed that the new PfSPZ Vaccine developed by scientists at Sanaria is effective and safe to use.
Malaria is caused by mosquitoes. When a mosquito bites a human, malaria parasites in the immature, sporozoite stage of their life cycle enter the body. They first travel to the liver where they multiply and then spread throughout the body through the bloodstream.
PfSPZ is a new malaria vaccine made from weak sporozoites of the species Plasmodium falciparum, the most deadly of the malaria-causing parasites.
“The global burden of malaria is extraordinary and unacceptable,” said NIAID Director Anthony S. Fauci, in a press statement. “Scientists and health care providers have made significant gains in characterizing, treating and preventing malaria; however, a vaccine has remained an elusive goal. We are encouraged by this important step forward.”
The trial was conducted on 57 healthy adult volunteers aged 18 to 45 years, who never had malaria. Forty of these participants received the vaccine and the rest didn’t. The participants who received the vaccine were further spilt into groups that received two to six intravenous doses of PfSPZ Vaccine in increasing dosages. They were then monitored for seven days.
Researchers found that participants who received higher doses of the vaccine developed more antibodies against the disease and more T-cells specific to the vaccine.
To measure the effectiveness of the PfSPZ Vaccine, all participants were exposed to bites by five mosquitoes carrying the P. falciparum strain from which the PfSPZ Vaccine was derived. Researchers found that participants who received higher doses of the vaccine were better protected against malaria infection.
“In this trial, we showed in principle that sporozoites can be developed into a malaria vaccine that confers high levels of protection and is made using the good manufacturing practices that are required for vaccine licensure ,” said Robert A. Seder, M.D., chief of the Cellular Immunology Section of the NIAID Vaccine Research Center and principal investigator of the trial.
No side effects of the vaccine were observed during this early stages of the clinical trial.