DNA is providing new clues to why COVID-19 hits people differently

Since the beginning of the pandemic, the mercurial nature of the coronavirus has been on display. Some people get mild, cold-like illnesses or even have no symptoms when infected, while other people become severely ill and may die from COVID-19.

What determines that fate is complicated and somewhat mysterious. Researchers are looking at a wide variety of factors that may play a role — everything from demographics to preexisting conditions to vaccination status and even genetic clues.

Researchers know that older people are more likely to have severe complications of the disease. The unvaccinated, too, have an increased risk of hospitalization and death compared with people who have gotten their COVID shots. 

Unvaccinated people age 50 and older were 12 times as likely to die from COVID-19 as vaccinated people who had gotten two or more booster shots, August data from the U.S. Centers for Disease Control and Prevention indicate. For instance, among the unvaccinated there were 5.46 deaths per 100,000 people on August 28, compared with 0.49 per 100,000 for…