Who recovered from COVID-19? A nationwide survey is being launched
Medical Research Agency in cooperation with National Institute of Public Health - PZH on behalf of the Minister of Health launches "Nationwide Sero-epidemiological Study COVID-19: OBSER-CO". The project aims to assess the actual prevalence of SARS-CoV-2 virus in Poland.
Current studies show that COVID-19 is asymptomatic in about 20-30% of cases, which makes the assessment of the epidemiological situation of SARS-CoV-2 incidence/infection in Poland based only on the registered cases limited and does not fully reflect the real status of virus prevalence in the population.
The project under the direction of Grzegorz Juszczyk, MD, PhD will allow to answer the question: what is the real percentage of population in Poland that has already been infected with SARS-CoV-2 and has immunity against this disease. To this end, the project envisages sero-epidemiological testing by performing a blood test for antibodies to SARS-CoV-2 in the study group.
By comparing the rate of antibody detection with the rate of registered infections in relation to the population (cumulative incidence) it will be possible to determine the number of unrecognized infections. In most countries/regions where such studies have been performed, the estimated percentage of unrecognized infections ranges from as high as 95% to almost 99%.
Estimating the true proportion of SARS-CoV-2 infections in the population will allow epidemiologists to better model the course of the epidemic. A large percentage of immunized people slows down the spread of the virus and therefore allows for greater control of the epidemic and therefore important organizational decisions and loosening of restrictions. Without this information, decisions about possible tightening must be made based on more pessimistic forecasts.
The OBSER-CO survey will be conducted in three rounds. In the first two rounds (March and July 2021) 11850 people from all provinces and age groups will be examined, in the third round (December 2021 / January 2022) - 6300 people over 60 years of age. In the questionnaire accompanying the blood test, data will be collected on information about a previous illness or contact with an infected person, the way you work, follow instructions, or participate in public events. The survey will also assess the immunization status of various groups, including occupational groups and other factors, thus complementing routine vaccination reporting.
Data from the NIZP-PZH project may provide additional information on the persistence of immunity after natural infection with SARS-CoV-2, the most common exposures to the infection, and the production and persistence of antibodies after vaccination. The results obtained in territorial distribution and by age and occupation groups may also provide additional information for modification of the previously identified priority groups of the population eligible for vaccination.