A 33-year-old German businessman gets the chills and a cough, but just three days later, feels better and goes back to work. A 39-year-old father and professional DJ in Florida with no obvious health conditions spends nearly two weeks in intensive care, only to die. It may not seem like they had the same disease, but they are among the more than 2.5 million people worldwide who have been sickened by covid-19.
One of the most distinctive and perplexing features of the disease, which has killed nearly 200,000 people globally, is the wide variation in severity. Some people don’t even show symptoms, while others suffer lethal damage to their lungs and other organs, and many more are somewhere in the middle.
As scientists around the world work at breakneck speed to try to answer questions about this mysterious new illness, one key concern is this dramatic difference in the responses of people infected with the same virus.
Age, sex and underlying health conditions clearly play an important role. But as geneticists, we think that — as for many medically relevant differences between individuals — some of the difference could be explained by the natural variation in people’s genetic code. After all, genetic differences can increase a person’s risk of heart attack, cancer or other deadly diseases. Or the differences can reduce risk, as is the case of several genetic variants that protect individuals from HIV infection.
Figuring out how genes influence responses to the virus could help the development of effective treatments or vaccines, or even point to an existing drug that could be repurposed as a covid-19 drug. Such repurposing is not new: Aspirin was developed as a painkiller but is commonly used as a blood thinner to prevent heart attack.
In early March, we started talking about the possible role of genetics in responses to the virus. When we reached out to fellow geneticists in other countries, we quickly realized that we weren’t the only ones thinking along those lines.
A few weeks later, we launched the Covid-19 Host Genetics Initiative, which aims to bring together scientific groups around the world to study the role of the human genome in explaining covid-19 severity and susceptibility.
What have we learned so far? From a scientific perspective, the effort is in its infancy, but we expect to have first study results by the end of May. For a completely new kind of global genetics collaboration, we are moving at an unprecedented speed.
Such swift progress demonstrates how, in a worldwide emergency, even when many researchers have had to put their laboratory work on hold and stay home, scientists from many disciplines will quickly step forward to help. Within just a few weeks of our building a website and posting on social media, more than 600 scientists from more than 45 countries joined this collaborative effort, registering more than 150 different studies aimed at gaining insight into the genetics underlying covid-19 variability.
Progress on this research relies on citizen participation. Many of the studies involve research in biobanks, which have already collected DNA and medical histories of several million people in Britain, the United States, Finland and other countries. In these studies, researchers can cross-reference covid-19 cases with these resources to learn new information about covid-19 risk and protection. Many other studies are starting up in hospitals and academic medical centers to look at covid-19 patients with different symptoms. All of these studies, and biomedical progress in all diseases, depend on the willingness of individuals to consent to having their DNA and medical information used in research.
Many more studies will emerge over the coming months. Some of us are searching for genetic markers associated with disease severity and outcome. Others are focusing on how the immune system might be affecting the course of the disease. Much work is left to do, and how this research will play out remains an open question.
Nonetheless, these past few weeks have shown us that at a time when so many of us are physically distant from one another, when borders are closed and travel restricted, we as scientists are still finding ways to come together, build new ties and openly collaborate, all motivated by a single, common goal: helping to stop this awful disease.