Researchers have examined many possible approaches for vaccines against malaria, a parasitic illness spread by mosquitoes that affects hundreds of millions of people each year. One of the most promising approaches thus far has been a subunit vaccine: a vaccine candidate using this approach, RTS,S, is in late-stage clinical trials.
Researchers in Queensland, Australia have begun testing another approach, however: a vaccine that combines killed parasites with an adjuvant to boost immune response. The resulting vaccine was tested in mice, and was shown to provide long-lasting, cross-strain protection against malaria.
The group focused on developing a vaccine with the lowest possible dose of killed parasite that would still elicit a protective immune response. Their test vaccine induced a broadly reactive T cell response of the type usually generated by live, attenuated vaccines–yet with a safety profile more in line with a killed vaccine.
The researchers caution that it is not yet known whether similar responses could be generated in humans. Still, the work may yield another promising approach to malaria vaccination.
Alberto Pinzon-Charry, Virginia McPhun, Vivian Kienzle, Chakrit Hirunpetcharat, Christian Engwerda, James McCarthy, Michael F. Good. Low doses of killed parasite in CpG elicit vigorous CD4+ T cell responses against blood-stage malaria in mice. J. Clin. Invest. 2010; doi:10.1172/JCI39222
Link to paper: http://www.jci.org/articles/view/39222
Centers for Disease Control and Prevention — Malaria information