What Mrs. Burkett and Mrs. Miller experienced was not the norm. Many of the conditions that can increase a person’s risk for severe Covid – overweight, heart disease, diabetes, smoking – are highly influenced by the environment and behavior, not just by genetics. The story of a person battling other coronaviruses, such as those that cause common colds, can also affect the likelihood of developing a serious case of Covid.
Some researchers have also suggested that the amount of coronavirus that a person ingests can have an impact on the severity of the disease, a trend that has been documented with other infections.
“It’s the difference between having your immune system really able to crush the infection, or having a much harder time fighting it if all the cells are infected at the same time,” said Juliet Morrison, a virologist at the University of California, Riverside.
Michael Russell, 29, says he wonders if he sniffed more of the virus than his twin, Steven, this summer, in the days after reuniting with his family for the 4th of July.
The two brothers began to experience symptoms shortly after the celebrations ended, around the time Steven returned to his home in Arlington, Virginia. The virus left Steven with a sore throat and a headache – a “mild, cold-like illness”, he said.
A few days later, Michael, who lived at home with his parents, had much more severe symptoms: sore throat, chills, shortness of breath and fatigue that relegated him to bed for an entire day. About two weeks passed before he could smell or taste the cinnamon powdered popcorn that he regularly eats.
The twins’ parents also had severe Covid symptoms, so Michael had to isolate himself with two other infected adults. Staying together in the same house may have exposed you to a higher dose of the virus, the brothers said. But, they added, this is just a guess.