New malaria targets found

Several new malaria vaccine targets have been identified by a UK research team, British researchers have announced.

Any of the targets could form the basis of an effective vaccine in the future, the researchers say.

"A highly effective vaccine would be a valuable weapon in the drive toward malaria elimination," said Dr Gavin Wright of the Wellcome Trust Sanger Institute, Cambridge, UK, and colleagues in Proceedings of the National Academy of Sciences on Monday (23 October).

They add: "No such vaccine currently exists, and only a handful of the hundreds of potential candidates in the parasite genome have been evaluated."

In this study, they evaluated 29 antigens that they believed were likely to be involved in an important stage during which the malaria parasite is vulnerable to antibody-mediated inhibition, called erythrocyte invasion. At this stage, the malaria parasite is invading human red blood cells.

The 29 antigens were tested both alone and in combination. This led to the identification of five targets that had "synergistic combinatorial effects" in lab tests. The team point out that the five antibodies they identified were associated with natural protection against malaria in people in an endemic population.

Dr Wright said: "Producing a successful vaccine against parasites is challenging because they are very complex organisms with many components, making it difficult to know which ones to target. By studying the parasite’s genome and working backwards, in a process known as reverse vaccinology, we have discovered five vaccine targets which, if combined, show promise for further development."

Co-author Professor Pietro Cicuta of the University of Cambridge, UK, added: "These results give insight into a new, synergistic view of vaccine development. We believe a new vaccine would be the most effective if it put roadblocks at several points along the parasite’s path into the red blood cells."

Bustamante, L. et al. Synergistic malaria vaccine combinations identified by systematic antigen screening. 23 October 2017 PNAS doi: 10.1073/pnas.1702944114 [abstract]