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The coronavirus pandemic is still far from over, but humanity has already learned some lessons from it, for example, that there are more questions than answers.
The first known death in the world due to reinfection by coronavirus. Previously, when it became clear that immunity didn’t last forever, scientists assumed that the second case of COVID-19 would be easier for humans to carry.
However, until now SARS-CoV-2 remains the most mysterious virus: neither the duration of its life on surfaces, nor the appearance of immunity, not even the symptoms are known. Correspondent.net says the details.
More and more questions
On October 12, the Dutch media reported the death of an 89-year-old patient after a reinfection with cornavirus. It is known that he suffered from Waldenstrom’s macroglobulinemia, a rare form of lymphoma.
The woman was admitted to the hospital for the first time several months ago with a fever and severe cough. His coronavirus test came back positive. Despite her cancer-damaged immune system, after five days in the hospital, her symptoms subsided and the woman was discharged only due to fatigue.
Two months later, a new course of chemotherapy began and soon the temperature rose, the cough returned, and difficulty breathing developed. During a new hospitalization, her COVID-19 test also came back positive. After a week, his condition got much worse and after two more he died.
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There are 23 known cases of coronavirus reinfection worldwide. In most of these cases, the reinfection was less severe than the previous infection. The first such incident occurred with a 33-year-old Hong Kong resident.
Also on October 12, The Lancet, the most authoritative medical journal, published an article describing the first confirmed case of coronavirus reinfection in the United States. The reinfection also led to more serious illness, according to the study.
A 25-year-old Nevada resident with no autoimmune diseases received his first positive PCR test for coronavirus on April 18. He recovered during quarantine and received two negative tests at different times, however after 48 days the patient’s test results came back positive.
In less than two months, the article says, a patient from Nevada was infected with two different strains of SARS-CoV-2.
“It is concerning that reinfection led to a more serious illness than the first infection, which resulted in oxygen support and hospitalization,” the study authors emphasize.
The illness was also accompanied by high fever, headache, dizziness, cough, nausea, and gastrointestinal upset.
They also pointed out that the fact that the man’s test results were negative twice between illnesses makes it unlikely that he suffered a long-term case of COVID-19.
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The head of the study, Dr. Mark Pandori of the University of Nevada, says that it is not yet clear how long immunity lasts after the first infection with the coronavirus, but it is already clear that reinfection is still possible.
The study authors proposed several hypotheses that explain the more severe course of the disease for the second time. According to one of them, the patient could have been exposed to a very high viral load a second time, causing a stronger reaction, or faced with a more virulent version of the virus.
Another hypothesis is that the cause of severe symptoms in the second infection could be an antibody-dependent surge in infection, a mechanism by which viruses use the immune system to destroy the body even more effectively and massively.
Scientists have already observed this phenomenon in the SARS-CoV coronavirus and other diseases such as dengue fever.
In this case, the virus uses the “host” antibodies as a “Trojan horse”: the infection-enhancing antibodies, which bind to the virus, do not fight it, but ensure its more complete absorption by the cell, thus facilitating its multiplication.
Finally, another explanation could be the possibility of simultaneously infecting a patient with two strains of the virus at the same time. This would mean that the second strain went unnoticed in the first study in April. And in June, the body had completely overcome the first stress.
On October 13, researchers from the Finnish Department of Health and Social Development THL and the city of Helsinki said that antibodies formed in the body as a result of the coronavirus infection persist for four months.
The scientists came to this conclusion after studying data from 39 families in which cases of coronavirus were detected. Almost all infected people developed antibodies during the first month of infection, which were detected after four months.
This study confirms previous work by scientists, which showed that the antibodies persist for three to four months. However, the mechanism for the development of immunity to SARS-CoV-2 remains unexplored; it may depend not only on the presence of antibodies.
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