Doctors conducted a study of blood samples from residents of the Chinese city of Wuhan, which at the end of last year became the epicenter of the spread of coronavirus in the world, and found that by the beginning of summer 2020, about 4% of those examined had antibodies to COVID-19. The experts’ findings were published in an article in JAMA Network Open on Friday, October 23rd.
The study was conducted at Tongji Hospital of Huazhong University of Science and Technology from March 27 to May 26. Samples were collected from just over 35 thousand city residents over 18 years old. However, none of the participants had a history of COVID-19.
“This study found that the seropositive prevalence was 3.9% in a cohort of 35,040 people in Wuhan, China. Most people tested positive for SARS-CoV-2 IgG antibodies only, which indicates a prior infection, ”the researchers said.
The presence of antibodies during the experiment was more often recorded in residents of urban districts than in the suburbs. Moreover, more often antibodies were detected in the body of women (4.4%) than men (3.3%). At the same time, the prevalence of antibodies among the studied samples was higher in people over 60 years old.
“It is possible that older adults had a higher proportion of comorbidities that could contribute to SARS-CoV-2 infection and increase the severity of COVID-19,” the researchers suggested.
On the eve of the director of the Center for Epidemiology and Microbiology. Gamalei Alexander Gintsburg told Izvestia that in 10-15% of cases, antibodies quickly disappear even in patients who have been seriously ill with COVID-19. Two days earlier, Gunzburg said that antibodies to coronavirus during vaccination are produced worse in the elderly, drinkers and people under stress, as well as in those taking anti-inflammatory drugs.
In turn, the head of the Department of Medical Informatics and Statistics of Sechenov University, Andrei Gerasimov, said that in order to develop collective immunity to coronavirus, it is necessary to vaccinate 52% of the population, taking into account risk groups. However, with a random sample, at least 64% of the population must be vaccinated.
The spread of the SARS-CoV-2 coronavirus, which causes the disease COVID-19, began at the end of December last year. The Chinese city of Wuhan became the hotbed of infection. For several months, the disease has spread to more than 210 countries of the world. On March 11, WHO declared a coronavirus pandemic.
According to the International Bureau of Statistics Worldometer, more than 42.2 million confirmed cases of coronavirus have been registered in the world today, over 1.145 million people have died, and almost 31.3 million patients have recovered.