October 30, 2020 - Podcast

Episode 52—COVID-19 timeline, and artificial light

Experts have learned a lot about SARS-CoV-2, the virus that causes COVID-19, since the pandemic began. However, there are still many unknowns. One burning question is how long it will stick around. John Patton, a professor of biology and virology at Indiana University, says he doesn’t see the virus going away, but instead becoming an endemic virus, like cold viruses and flu viruses. It will be with us, Patton says, and we will have to control it and mitigate the worst symptoms. One of the big unknowns is immunity. Experts are still learning about the possibility of reinfection with SARS-CoV-2. While researchers aren’t sure whether people can become infected more than once, Patton says because we're dealing with a coronavirus, we already know infection likely doesn’t lead to permanent immunity. Another factor is vaccines. An initial vaccine may not have high efficacy, Patton says, and we likely won’t have a vaccine that offers lifelong protection. Most of the vaccines that are being generated look like they’re going to provide us with some sort of protection, he says, but it's not likely that the nature of this protection is going to be a permanent, sterilizing immunity. Patton adds that even if a vaccine isn’t highly effective in preventing infection, it could still lessen COVID-19 symptom severity and reduce the risk of death. Plus, vaccines aren’t the only area of research scientists are working on. Even if we cannot eradicate SARS-CoV-2, that doesn’t mean the virus will remain at the same threat level it is currently. Patton says he’s been impressed with is how much better we are doing in developing effective therapeutics and treatment methods.

In other news, although artificial light certainly helps us humans navigate the world, disruptions to Earth’s natural light cycle come at a cost to local and migrating wildlife. A recent study by Indiana University researchers found that long-term exposure to artificial light at night caused dormant malaria infections in birds to intensify, especially during periods when birds experienced physiological changes in advance of migration and reproduction. Since birds can serve as reservoirs for human diseases such as West Nile and Lyme disease, the effects of artificial light on birds could increase the risks of parasite transmission to other species, including humans. For the vast majority of organisms, the cycle of light and dark is an important regulator of behavior, says IU Distinguished Professor of Biology Ellen Ketterson, a co-author of the study. Disrupting that cycle is probably not a good thing to do, but that’s exactly what humans are doing by using artificial light, she says. And as we’ve seen with COVID-19, Ketterson says, the health of wildlife can have consequences for human health. If infections are flaring up in birds that spend time in urban habitats, people may need to think about what can be done to lower the risk of parasite transmission. In the study, the researchers, led by postdoctoral researcher Daniel Becker, looked at blood samples from birds during key times of the year and counted the number of malaria parasites in each sample to gauge the birds’ health and the effect of artificial light. Over the course of the experiment, researchers found a dramatic increase in parasite intensity and high numbers of white blood cells, a sign of an exaggerated immune response. So, short of turning out the lights, what can be done to limit the harmful effects of artificial light? Researchers suggest replacing white lights with warmer lights which can have less of an impact on wildlife or limiting use of bright lights during intense periods of bird migration and breeding in the spring and migration in the fall. By reducing the amount of bright light outside during certain times of year, we might be able to buffer its effects on birds and other species.