A new kind of malaria vaccine impressed researchers in an early clinical study, providing hope that protection against the lethal parasite could become widely available in several years. And the clinical trial results, published in Science, put vaccine developer Sanaria in the global spotlight.
Pharma companies and scientists have struggled to create a highly effective vaccine against malaria, which is caused by complex Plasmodium falciparum parasites that killed 660,000 people in 2010, according to the World Health Organization. Rockville, MD-based Sanaria's vaccine candidate, PfSPZ, is designed to protect against the tricky parasites by eliciting antibody responses--like most shots--as well as powerful T-cell attacks on the foreign invaders.
Sanaria's vaccine candidate is made with a weakened form of the whole parasite, rather than only a fragment, to provide the broader immune response. So far the approach seems to work, albeit in a small Phase I study. In Science researchers report that 12 out of 15 volunteers treated with the PfSPZ candidate avoided malaria infections after being exposed to the parasite, compared with 5 out of 6 nonvaccinated people in the study who developed the disease. Sanaria aims to validate the findings in larger clinical trials in the U.S., Europe and Africa.
The Phase I study showed that the vaccine worked for the majority of treated patients three weeks after getting vaccinated. Further studies would need to show how well the vaccine protects against malaria for a much longer time, NPR reported. For instance, the protective powers of GlaxoSmithKline's ($GSK) experimental malaria vaccine RTS,S have been tested over a matter of years. And disappointing results reported in March showed that the effectiveness of the shot wears off over time.
However, scientists sound optimistic that the novel approach from Sanaria could succeed in later-stage development.
"It's true to say that this is really impressive to have this degree of protection," Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases (NIAID), an NIH unit that backed the study, told NPR. He added that the results were "unprecedented," while noting that "you have to temper it by saying the numbers are still relatively small."
Sanaria CEO Stephen Hoffman stated that his company's malaria vaccine could become widely available in three to 5 years. A highly effective vaccine would be a breakthrough because none exists on the market today.
- here's the company's release
- see the Science abstract
- and the article from NPR