What Mrs. Burkett and Mrs. Miller experienced was not the norm. Many conditions can It increases a person’s risk For severe Covid-19 – excess weight, heart disease, diabetes, smoking – is strongly influenced by environment and behavior, not just genetics. A person’s history of fighting other coronaviruses, such as those that lead to the common cold, may also affect the likelihood of developing a serious case of Covid.

Some researchers also put forward the idea that the amount of coronavirus a person ingested may have an effect on disease severity, a trend that has been documented with other infections.

„It’s the difference between having your immune system actually being able to eliminate an infection, or having a much greater difficulty fighting it if all of your cells are infected at the same time,“ said Juliet Morrison, a virologist at the University of California, Riverside. .

Michael Russell, 29, says he wonders whether he inhaled more virus than his twin brother, Stephen, did this summer in the days following their meeting with their family on the Fourth of July.

The siblings began experiencing symptoms shortly after the celebrations ended, by the time Stephen returned to his home in Arlington, Virginia, where the virus had caused Stephen to develop a sore throat and headache – an illness „as mild as a cold,“ he said.

A few days later, Michael, who was living at home with his parents, developed more severe symptoms: a sore throat, chills, shortness of breath and exhaustion that put him in bed for the whole day. About two weeks passed before he smelled or tasted the cinnamon-coated popcorn he consumed regularly.

The twins‘ parents had bad Covid symptoms as well, so Michael had to isolate two infected adults. The brothers said that hanging out together in the same house could expose them to a higher dose of the virus. But, they added, this is only a guess.