Covid-19 reinfection can occur with stronger symptoms, according to a study released this Wednesday by the Oswaldo Cruz Foundation (Fiocruz), the largest scientific research center in Brazil and Latin America.
According to the study, that was published in the magazine Emerging Infectious Desease (EID) of the Centers for Disease Control and Prevention (CDC) and will be out in the May issue, people who were mildly infected with covid-19 and did not require hospitalization, would not have produced an immune response, which would increase the chances of reinfection, even with the same variant that infected them the first time.
According to the research, if a person is reinfected by the same variant “It is because the patient would not have created an immune memory” and in the case of another variant, this would happen because it would “escape” from surveillance and would not be recognized by the memory generated previously, because it is a little different.
To reach these conclusions, the researchers weekly followed to a group of 30 people from the beginning of March 2020, when the pandemic had just arrived in Brazil, and until the end of the year. Of them, four contracted SARS-CoV-2 and some were reinfected by the same variant.
In all four cases, the first infection occurred with mild symptoms, while in the second infection, the symptoms were more frequent and stronger, but did not require hospitalization.
“These people did not really have a detectable immunity until after the second infection. This leads us to think that for a part of the population that had the disease mildly, not just one exposure to the virus, but more than one, is enough to have some degree of immunity, “he explained Thiago Moreno, Researcher at the Fiocruz Center for Technological Development in Health and coordinator of the study.
Although so far the possibility of contracting COVID-19 has only been studied twice, Moreno does not rule out that a third could occur.
“We do not know how long postcovid immunity lasts. A person could be vulnerable to a new reinfection or even to contract a different variant,” he said.
The study also included researchers from the Federal University of Rio de Janeiro (UFRJ), the D’Or Education and Research Institute (Idor) and the Chinese company MGI Tech Co.
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