A number of Americans are dealing with a coronavirus reinfection, months after initially defeating it.
Two men have been cited as the country’s first documented cases of reinfection, according to WebMD. A 25-year-old Nevada man and a 42-year-old Virginia man were both hit with a second bout of COVID-19 around two months following their initial positive tests. There have been multiple instances of reinfection in other areas of the world, including Hong Kong, Belgium, and India.
These cases differed from the examples in the U.S., however, due to one vital element. The Americans experiencing a coronavirus reinfection report that their symptoms are far more severe the second time around. Previously reported second infections have primarily been labeled as similar to the initial bout, with the exception of a case in Ecuador.
Several other Americans have been reinfected with the coronavirus in the days since the first reported cases. An Idaho woman caught COVID-19 in March, and in October, she went back in the hospital with severe symptoms. She noted to KTVB that her March case was far more mild than her reinfection. Another man, who has since recovered, required hospital treatment after his lungs couldn’t pump enough oxygen into his body.
Earlier this summer, a man from Hong Kong was thought to be the first person in the world to have a reinfection.
In each case, researchers determined that the patients were reinfected with a slightly altered strain of COVID-19. “Our findings signal that a previous infection may not necessarily protect against future infection,” Mark Pandori, the director of the Nevada State Public Health Laboratory, told the BBC. “The possibility of reinfections could have significant implications for our understanding of COVID-19 immunity.”
These findings mean that face masks, hand washing, and social distancing remain a necessary part of life even for those who have recovered from the coronavirus. In the case of some viruses, immunity following infection can last years. With COVID-19, however, it appears to only last a few months in some patients.
Typically, the development of antibodies helps to protect the body from reinfection. Dr. David Pate, the retired president and CEO of St. Luke’s Health System, noted that COVID-19 antibodies disappear more quickly than expected.
“Of people who do develop the antibodies, which is the majority, it does tend to wane,” Pate told KTVB. “It tends to drop down the levels such that at several months somewhere between 16% and 40% of people may not even have measurable antibodies anymore.”
Yet, cases of reinfection appear rare. Out of more than 38 million cases globally, only a few people have reported reinfection. As noted by Michael Mina, an epidemiologist and immunologist at Harvard, these rare cases should not be taken as proof that no one can build immunity or that vaccines are ineffective. “Re-exposures are essential to build our immune system,” he wrote via Twitter. “This is not in question. They are like training. But like anything, when enough people get a re-exposure, there are going to be rare cases here and there that go awry and someone gets more sick the second time.”