Third in a series on malaria immunology from graduate student Taryn McLaughlin. Sorry for the delay last week, caused by technical blog glitches.
It’s easy for me to find reasons to brag when it comes to research here at Emory. However, even an unbiased person should be excited about the malaria vaccine platform being developed by Alberto Moreno at the Emory Vaccine Center.
His vaccine is based on a chimeric protein (a protein that is a combination of bits and pieces of multiple proteins, a la the creature from Greek mythology) that should get your immune system to target multiple stages of the Plasmodium vivax life cycle. Part of it targets the infectious sporozoite, part of it targets the blood stage merozoite, and part of it will even target the transmitted gamete in future versions. This seems like a no brainer. Of course we should be targeting multiple stages!
The difficulty in eliminating the pre-erythrocytic stage and the exponential growth following liver invasion make it incredibly challenging for single stage vaccines to be effective in preventing disease.
Furthermore, the protein is being delivered via novel viral vectors (a wimpy virus that won’t make you sick and has Plasmodium proteins on its surface). This is important because, as I discussed previously, you need CD8+ T cells (not just antibodies) to effectively fight Plasmodium and protein vaccines are bad at trigger this kind of response. Viral vectors on the other hand are really good at generating this kind of response. By piggy-backing the proteins on a viral vector, the vaccine is able trigger many different arms of the immune system.
So in theory not only should this vaccine be able to induce a comprehensive immune response in terms of the plasmodium life cycle, but it should also be able to elicit the right kind of immune response. And so far the animal models have shown this to be true. Hence my bragging. We’re still a ways off from getting this through the rigorous testing of clinical trials, but science requires optimism.