KING COUNTY, Wash. — Doctors say a patient in the Seattle area is confirmed to have been reinfected with COVID-19, in only the third documented case of reinfection in the U.S. Researchers at Swedish Medical Center in Seattle are studying what the reinfection could tell them about how long immunity lasts, and how effective a vaccine could be.
The only other documented second infections were a 35-year-old man in Hong Kong, and a 25-year-old man in Reno, Nevada.
“We don’t know how much immunity levels we need to be protected,” said Dr. Jason Goldman, who leads the COVID Research Team at Swedish Medical Center.
In the Seattle case, the patient was in their 60s living in a nursing facility and was hospitalized after being infected the first time.
About 140 days later, the patient developed very mild symptoms after being infected a second time, and Goldman said that’s encouraging news.
“Most of the reported cases are more mild the second time around,” he said. “So even if the immune system has failed to prevent a second infection, it does seem to be limiting the severity the second time around.”
Goldman said it appears that the antibodies your body develops with an infection works the majority of the time and can make a second exposure easier.
“In the vast majority of patients who have gotten infected with COVID have recovered and not been re-infected, so that’s the second reassuring finding.”
Goldman’s study could help the world better understand how long COVID-19 antibodies last. Every case of second infection happened at least a quarter of a year after recovering from the first one.
“Most cases had four or more months from the first infection to the second, so that may be an inflection point perhaps,” he said. “Our immunity (may) start to wane then, but we really don’t know that yet.”
Goldman said there is a slightly different strain of coronavirus from the one which came out of Wuhan, China, in January, and future studies will help to find out how our immune systems have to react to be safe.
The vaccines being tested now are based on the original COVID-19 virus from China. But the most prevalent global circulating strain is slightly different. The different strain is called “D6-14G” and could be even more infectious than the original virus.
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