The trial of a new malaria vaccine on both humans and mice has been successful and could help eradicate the disease that causes at least one million deaths annually, researchers say.
Pierre Druilhe and his team at the Pasteur Institute here injected an MSP-3-based vaccine into 30 European volunteers who had never had malaria, re-administering it after one month and again after four months, the online edition of Scientific American reported.
Blood samples were taken one month after each injection. These blood samples were then compared to blood samples from people in France who had no immunity to malaria and blood samples from African people with immunity.
Nearly every vaccinated sample produced an immune response to malaria when it was introduced in vitro and 77 percent produced anti-MSP-3 antibodies.
These antibodies proved to be as good at killing the parasite as those from immune adults and, in some cases, better, destroying up to twice as many.
"This type of immune response, characteristic of immune adults living in malaria-endemic regions, requires, under natural conditions, 10 to 15 years of daily exposure to billions of infected red blood cells," Druilhe notes.
Malaria - a parasite carried by certain mosquitoes - sickens more than 300 million people worldwide every year, according to the World Health Organization. Vaccine development has been hindered by the microscopic parasites adaptability and complexity.
The scientists also did in vivo experiments in mice, infecting them with the parasite and then injecting a small amount of the vaccine-produced antibodies.
The antibodies significantly cut the number of parasites in the blood of these animals and in some cases wiped them out entirely - outperforming even the immune systems of naturally resistant humans.
The vaccine also showed long-lasting promise, with blood from some of the immunised individuals showing strong resistance a year later.
"This is the first malaria vaccine clinical trial to clearly demonstrate anti-parasitic activity by vaccine-induced antibodies," Druilhe said.