Collective immunity to SARS-CoV-2 of Moscow residents during the COVID-19 epidemic period

Abstract

The coronavirus disease pandemic (COVID-19) was announced by WHO in February 2020. In Moscow, the first case of the disease was detected on March 2, 2020 in a man who arrived from Italy. Two weeks after the first case, there was an exponential increase in the number of cases. The incidence peaked in the 19th week of the year, followed by a steady decline, lasting 16 weeks. Objective. To investigate the level and structure of population immunity to the SARS-CoV-2 virus among the population of Moscow against the background of the incidence of COVID-19. Patients and methods. The study of population immunity of Moscow residents to SARS-CoV-2 was carried out in the period from July 1, 2020 to July 30, 2020 against the background of stabilization of the incidence rate. The work was conducted as part of the first stage of the Rospotrebnadzor project to assess population immunity to the SARS-CoV-2 virus among the population of the Russian Federation, taking into account the protocol recommended by WHO. Volunteers for the study were selected by the method of questioning and randomization. The results of the survey of 2688 people were included in the analysis. The number of volunteers in all age groups was 384–385 people. The content of specific IgG to the SARS-CoV-2 nucleocapsid was determined by the enzyme-linked immunosorbent assya using a kit produced by FBIS SRCAMB according to the manufacturer's instructions. Results. During the survey of volunteers it was found that the share of seroprevalent residents of Moscow was 22.1%. By age groups, the highest proportion of seroprevalent was found among children aged 14–17 years (44.6%), the lowest (15.9%) – among people aged 18–29 years. Seroprevalence had no gender differences. The lowest level of herd immunity was revealed in the North-Western Administrative District (16.8%), the highest – in the South-Eastern Administrative District, as well as in the Troitsky and Novomoskovsky Administrative Districts of Moscow (in both, 24.1%). The smallest number of seropositive persons was among cultural workers (5.8%), the largest – among medical workers (27.0%). In the presence of contacts with patients with COVID-19, the probability of seroconversion increases by 1.5 times, and among convalescing persons COVID-19 antibodies were detected in 60.0% of cases. The proportion of people with asymptomatic infection among seropositive residents was 82.4%. Conclusion. The results obtained make it possible to characterize the population immunity of Moscow residents and are essential for the planning and implementation of anti-epidemic measures during the incidence of COVID-19. Key words: coronaviruses, SARS-CoV-2, seroprevalence, population, COVID-19

SARS-CoV-2 Seroprevalence Structure of the Russian Population during the COVID-19 Pandemic

“…Perhaps the publication of this English version of the work will help to fill in information gaps to some extent. Further, it is worth mentioning that a large group of authors have already published 16 articles in Russian publications under the auspices of the head of Rospotrebnadzor, Professor A. Y. Popova [ 17 , 18 , 19 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ].…”

Assessing of Humoral Immunity to SARS-COV-2 in Residents of Orenburg During the Epidemic Period

“…С другой стороны, лица, имеющие только IgG, -по нашим результатам их доля достигает 53,1%, -состав ляют прослойку переболевших среди населения. Однако это не свидетельствует о защищенности от COVID19, так как существует вероятность край не низкой эффективности формирования гумо рального иммунитета, что видно по отрицательным результатам тестирования на антитела [13].…”

“…В среднем этот показатель составил 25,0% со зна чительной разницей в обследованных возрастных группах: максимальный -в возрастной группе от 18 до 29 лет, минимальный -от 50 до 59 лет. Таким образом, определенное количество серо позитивных лиц демонстрирует бессимптомное течение [13,14]. С одной стороны, это вызывает опасения с точки зрения распространения вируса SARSCoV2, с другой -дает надежду как фактор, увеличивающий способность популяции противо стоять инвазии патогенного возбудителя.…”

Анализ Эпидемиологической Ситуации По Covid-19 В Енбекшиказахском Районе Алматинской Области

“…Кроме того, важно подчеркнуть формирование больных с долей населения, которые уже перенесли КВИ. Настоящий показатель позволит спрогнозировать формирование коллективного иммунитета в обществе [13][14][15]. Енбекшиказахский район с населением в 300 000 человек находится на первом месте по численности населения среди всех районов Алматинской области, в связи с чем взят нами для детального анализа заболеваемости КВИ.…”