Asymptomatic COVID-19 is linked to a gene variant that boosts immune memory

The big idea

A common genetic variant explains why some people are asymptomatic after being infected with the virus that causes COVID-19, according to our recently published study in the journal Nature.

Early in the pandemic, we were intrigued that many people did not develop COVID-19 symptoms while still testing positive for it. Because asymptomatic people are unlikely to seek medical help, we knew that collecting DNA samples to study the role of genetics in asymptomatic infections would be difficult. So instead, we took advantage of existing genetic data stored in the Be The Match U.S. bone marrow donor registry.

We invited volunteers registered as donors to track their experience with COVID-19 via a smartphone app developed by the COVID-19 Citizen Science Study. This allowed us to analyze the genetics of nearly 30,000 people without collecting biological samples and to identify COVID-19 positive individuals who never became sick.