Not saying it's related but I find it interesting that an article from 2006 2008 spikes to 51 in May 2019 Comparative Testing of Six Antigen-Based Malaria Vaccine Candidates Directed Toward Merozoite-Stage Plasmodium falciparum https://cvi.asm.org/content/15/9/1345/article-info Refresher Malaria Vaccines: Recent Advances and New Horizons https://www.sciencedirect.com/science/article/pii/S1931312818303202#bib110