Good question. Perhaps 6 or 7. A key vaccine that we discovered was to use an adenovirus to induce an antibody AND T cell response to a blood stage malaria protein. We showed that our approach could induce high levels of protection against parasite infection. Unfortunately, we didn’t see the same protection in humans, using that protein. However, the group have gone on to find some new exciting targets. They are also looking at combining multiple proteins to induce protection at the initial, liver, blood and mosquito stages. Check out the Jenner Institute at the University of Oxford.