Since their discovery in the 1970s, artemisinin-based drugs have become the mainstay of treatment for malaria caused by the Plasmodium falciparum parasite. Researchers have identified artemisinin-resistant malaria parasites in Southeast Asia since the early 2000s, but now, there is evidence of resistance in Rwanda and Uganda. Dr Betty Balikagala of Juntendo University tells us how this resistance developed and what it means for managing malaria in Africa, which carries the greatest burden of malaria cases and deaths worldwide.

We hear from some of the scientists from COVID Moonshot, a non-profit, open-science consortium which has just received key funding to develop affordable antivirals to stop SARS-CoV-2 in its tracks.

Also on the programme, Dr Rakesh Ghosh from the University of California, San Francisco tells us how air pollution is contributing to 6 million preterm births globally each year, and Dr Catherine Nakalembe of the University of Maryland and Africa Lead for NASA Harvest returns to the programme as NASA/USGS launches Landsat 9.

Also In the past 18 months we have heard lots about the human immune system, as we all learn about how our bodies fight off Covid-19 and how the vaccine helps protect us. But this got listener John, in Alberta, Canada, thinking about how trees and plants respond to diseases and threats. Do they have immune systems and if so, how do they work? Do they have memories that mean they can remember diseases or stressful events 5 months, or 5 years down the line, to be better prepared if they encounter the same threats again?

Presenter Marnie Chesterton sets out to investigate the inner workings of plants and trees, discovering that plants not only have a sophisticated immune system, but that they can use that immune system to warn their neighbours of an attack. Some researchers are also investigating how we can help plants, especially crops, have better immune systems – whether that’s by vaccination or by editing their genes to make their immune systems more efficient.

But some plants, like trees, live for a really long time. How long can they remember any attacks for? Can they pass any of those memories on to their offspring? Crowdscience visits one experimental forest where they are simulating the future CO2 levels of 2050 to understand how trees will react to climate change.

Image: Mosquito net demonstration in a community outreach centre in Kenya