Coronavirus LiveUpdateExBulletin

Healthcare professionals will test patients for the coronavirus in Nevada in July. Scientists say a 25-year-old Nevada man was infected twice with the virus. This is the first confirmed case of reinfection in the United States.

John Rocher / AP

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John Rocher / AP

Healthcare professionals will test patients for the coronavirus in Nevada in July. Scientists say a 25-year-old Nevada man was infected twice with the virus. This is the first confirmed case of reinfection in the United States.

John Rocher / AP

Nevada scientists confirmed that a 25-year-old child was infected with the coronavirus twice earlier this year. This is the first confirmed case of so-called viral reinfection in the United States and the fifth confirmed case of reinfection in the world.

These cases emphasize the importance of keeping a social distance and wearing a mask, even if previously infected with the virus, and how the human immune system reacts to the virus. I am asking questions.

The two infections in patients in Nevada reportedly occurred approximately every six weeks. Case Study Published in a medical journal on Monday Lancet.. The patient was initially virus positive in April and had symptoms such as coughing and nausea. He recovered in May and tested negative for the virus.

However, at the end of May, he went to an emergency medical center with symptoms such as fever, cough and dizziness. In early June, he tested positive again and was admitted to the hospital.

“The second infection was symptomatically more severe than the first,” the study author wrote. The patient survived a second seizure with COVID-19.

This was the second confirmed case of coronavirus reinfection, and the patient became ill for the second time.Patient Ecuador He also suffered a more serious case of COVID-19 during his second virus infection.

Scientists don’t know why. Theoretically, the body’s immune system makes antibodies after the initial infection and helps to fight the virus more effectively if a person is re-exposed to the same virus.

“There are many reasons why a person may get sick a second time,” said Akiko Iwasaki, a professor of immunobiology at Yale University who was not involved in Nevada research. For example, “the second time you may have been exposed to a much higher level of virus,” she says. Alternatively, the immune response from the initial infection can exacerbate the disease rather than improve it.

But she emphasizes that “this is all very speculative,” as scientists still have little information about how it works.

One of the biggest open questions is how widespread reinfection is. It is difficult to see cases where a person has been infected twice. Scientists need to have a nasal swab from both the first and second infections to compare the genomes of both virus samples.

Only state-of-the-art hospital and laboratory facilities have the equipment and personnel to perform genome sequencing and analyze the results. As a result, most cases of reinfection may go unnoticed.

Danny Altman, a professor of immunology at Imperial College London, says that about 90% of people who experience an “apparent sexually transmitted disease” have antibodies to fight another infection “probably for about a year.” Say it seems.

“Of course, it leaves 10% who don’t have enough antibodies to fight the second infection,” he wrote to NPR by email. “”[T]Hey, the number of reinfections is small but considerable, as everyone there is at exactly the same risk. “

The authors of the new study also found cases of people infected multiple times because some people exposed to the virus may not have started a sufficient immune response to protect themselves from a second infection. It raises the possibility of affecting the effectiveness of coronavirus vaccines.

However, Iwasaki states that such cases have nothing to do with the effectiveness of future vaccines. The virus can develop proteins and interfere with the immune response, she explains, but the vaccine does not contain those proteins. “The good thing about vaccines is that they can elicit much better immunity than natural exposure to the virus, much longer lasting immunity,” she says.