We’ve been hunkered down over the dark winter months in Edinburgh planning experiments and looking at data, and now that we are in a spell of warm spring weather we realise we’ve completed not one malaria challenge but two. Almost all of our participants in the BIO-004 trial returned for re-challenge in February (it went swimmingly) and we are now starting to plan for the third and final challenge, which kicks off in around 6 weeks. This will be the most complex step in the trial as we challenge half of the participants with falciparum malaria (which is widespread in sub-Saharan Africa) and the other half with vivax malaria (most commonly found in Asia and South America). Malaria is a truly global disease and the world is quickly changing around us - the decisions that have been taken by just a few will have a profound impact on malaria control for hundreds of millions who don’t have a voice in the debate. A recent report in the British Medical Journal makes plain the challenges we now face: https://www.bmj.com/content/389/bmj.r783.