Parasites are as complex; you can think of them as being as complex as a human cell. Because they code for 1000s of proteins, as opposed to viruses, which only have a minimal genome, they make only a handful of proteins,” Prakash Srinivasan, PhD, assistant professor, Johns Hopkins Malaria Research Institute said. “So, parasites are a lot more complex than viruses, and the reason why it becomes such a big challenge to develop vaccines against parasites, such as the malaria parasite plasmodium.”