Malaria: Live Attenuated Vaccine Provides Protection

Results of a clinical trial of Sanaria[R] PfSPZ (Plasmodium falciparum sporozoite) Vaccine to prevent malaria infections, published today in the online issue of Nature Medicine magazine, show that the vaccine provided protection against infection with malaria parasites for at least 14 months in subjects who were exposed to _Plasmodium falciparum_ parasites. The findings put the Sanaria vaccine on track to be the 1st malaria vaccine providing durable protection against infection with malaria parasites. _Plasmodium falciparum_ is the malaria parasite that causes about 438 000 deaths and 214 million cases annually. "The results completely change the landscape in terms of having a highly protective malaria vaccine with sustained protection within reach. The data from this trial support the design and conduct of ongoing studies by the International PfSPZ Consortium intended to finalize an optimized vaccine regimen for phase 3 clinical trials and licensure of a PfSPZ Vaccine regimen that protects greater than 80 percent of recipients for at least 6 months," said Stephen L. Hoffman, CEO of Sanaria. "We intend to use PfSPZ Vaccine for preventing malaria in individuals, halting transmission of the malaria parasite and eliminating the parasite through mass vaccine administration campaigns. It's reasonable to suggest that within 3-to-4 years a safe, reliable vaccine could be a commercial reality and provide medical benefit to a huge population." The National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH) funded the current trial with additional support from Sanaria. Sanaria also receives research support and funding from multiple other institutions in the United States, Europe, and Africa, most of which participate in the International PfSPZ Consortium and will continue its fund-raising efforts to expand its research and clinical programs. "Scientists have struggled for more than 3 decades to produce an effective malaria vaccine that provides durable protection against infection with malaria parasites. These results show that we are on the road to having a safe, successful, highly effective vaccine that has the potential to save millions of lives," said Dr. Marcel Tanner, President, Swiss Academy of Sciences and past director of the Swiss Tropical and Public Health Institute. Dr. Adel Mahmoud, a Princeton professor, former president of Merck Vaccines, and Sanaria board member, concluded, "The goal is a safe, well-tolerated, easily, administered, highly protective vaccine against malaria. As the clinical trials unfold, we are learning that PfSPZ Vaccine can meet all of these criteria." In the clinical trial reported in Nature Medicine entitled, "Protection against malaria at 1 year and immune correlates following PfSPZ vaccination", volunteers received intravenous inoculations of Sanaria[R] PfSPZ Vaccine, which consists of live, weakened, purified malaria parasites that do not cause illness. At 21 weeks after last immunization, 9 of 14 volunteers (55%) were protected against exposure to the bite of malaria parasite-infected (disease transmitting) mosquitoes. A total of 5 of the 9 volunteers protected at 21 weeks underwent repeat exposure to malaria parasite-infected mosquitoes at 59 weeks and all 5 (100%) were protected against infection. The trial included 101 adult volunteers, ages 21-45, who were divided into groups with 57 participants receiving the vaccine at varying doses to evaluate alternative dosage regimens. The vaccine was well tolerated and safe. Vaccine efficacy among volunteers was tested at 3 weeks, 21 and 25 weeks, and 59 weeks after the final vaccination. Participants were enrolled, vaccinated and assessed under the direction of Robert Seder, MD at the Vaccine Research Center, NIAID, NIH, Bethesda, MD, and Kirsten Lyke, MD at the Center for Vaccine Development, University of Maryland Baltimore School of Medicine. Future clinical trials of PfSPZ Vaccine in Africa, the U.S., and Europe are expected to lead to licensure of an affordable vaccine for use in mass vaccine administration campaigns in countries most affected by malaria and to prevent malaria in travelers. According to the World Health Organization, African children are hardest hit, and the disease primarily strikes in 17 African nations, with people in Democratic Republic of Congo and Nigeria most often stricken. Salim Abdullah, Chief Executive Director of Tanzania's Ifakara Health Institute, the site of 2 trials of PfSPZ Vaccine, including the first trial in infants, and the principal investigator of the first trial of PfSPZ Vaccine in Equatorial Guinea said, "We had always anticipated short term protective immunity to be induced by PfSPZ Vaccine. These data on more than 1 year of sterile protection opens the door to vaccine effectiveness beyond our previous expectations." In addition to the benefit to residents of Africa and other parts of the world with malaria, the vaccine will be used to prevent malaria in tourists, diplomats, business travelers, aid workers, industrial workers, and military personnel.