Researchers at Merck & Co., the PATH Malaria Vaccine Initiative (MVI), and the NYU Langone Medical Center have formed a consortium to evaluate a malaria vaccination approach that targets the circumsporozoite protein (CSP) on the surface of the malaria parasite.
The consortium is looking to develop a targeted peptide protein conjugate that blocks the function of CSP and prevents the parasite from entering the host liver. The research will exploit Merck’s expertise in conjugate vaccines against bacterial pathogens, and build on the promise of GlaxoSmithKline’s (GSK) Phase III-stage RTS,S malaria vaccine, which is being developed in partnership with MVI.
“We think we can improve the way subunit vaccines are designed by strategically targeting this critical protein function,” comments Elizabeth Nardin, M.D., at Langone Medical Center’s department of medical parasitology. “Other vaccine approaches targeting CSP have required extremely high levels of antibody, which are difficult to elicit and to maintain. This approach has the potential to address that problem.”
GSK’s RTS,S vaccine candidate is a recombinant protein that fuses a part of the Plasmodium falciparum CSP with the hepatitis B virus surface antigen. A large-scale Phase III efficacy trial in both infants and young children was initiated in May 2009, and is now under way in 11 sites in 7 African countries. The study will enroll up to 16,000 infants and children.