Corona Monitoring Nationwide (RKI-SOEP-2): Seroepidemiological Study on the Spread of SARS-CoV-2 Across Germany

Abstract

SARS-CoV-2, the coronavirus, spread across Germany within just a short period of time. Seroepidemiological studies are able to estimate the proportion of the population with antibodies against SARS-CoV-2 infection (seroprevalence) as well as the level of undetected infections, which are not captured in official figures. In the seroepidemiological study Corona Monitoring Nationwide (RKI-SOEP-2), biospecimens and interview data were collected in a nationwide population-based subsample of the Socio-Economic Panel (SOEP). By using laboratory-analyzed blood samples to detect antibodies to the SARS-CoV-2 virus, we were able to identify a history of vaccination or infection in study participants. By combining these results with survey data, we were able to identify groups within the population that are at increased risk of infection. By linking the RKI-SOEP-2 survey data with data from other waves of the SOEP survey, we will be able to examine the medium- to long-term impacts of the COVID-19 pandemic, including effects of long COVID, in diverse areas of life. Furthermore, the data provide insight into the population’s willingness to be vaccinated as well as related attitudes and conditions. In sum, the RKI-SOEP-2 survey data offer a better understanding of the scope of the epidemic in Germany and can help in identifying target groups for infection control in the present and future pandemics.

Nationwide population-based infection- and vaccine-induced SARS-CoV-2 seroprevalence in Germany at the end of 2021

“…The study included 11,162 participants aged 14-99 years from 6,760 households. 20,774 individuals aged 14 years and older from 11,785 households had been invited to participate (response 53.7% 16 ). Data were collected predominantly between November 2021 and January 2022 (Figure 1).…”

“…Study materials included a questionnaire of twelve pages, a disposable kit for the self-sampling of capillary blood from a finger prick, illustrated instructions and a link to video material on self-sampling. The questionnaire was available in seven languages and included questions on past SARS-CoV-2 infection (previous infection detected by PCR testing, date of positive test result, severity of illness), vaccination status (number of doses, date and site of vaccination, vaccine type), attitudes toward the pandemic, health status, and health behaviours 16 . It could be answered on paper or online.…”

Prevalence of Long COVID-associated symptoms in adults with and without SARS-CoV-2 infection in Germany: Results of the population-based study “Corona Monitoring Nationwide 2021/22” (RKI-SOEP-2)

“…Participation was mainly in November and December 2021 – a period with predominance of the Delta variant in Germany. Details of the study design have been previously published (13).…”

“…Survey-specific weighting factors were used to compensate for sampling design and non-random non-response. The weighting strategy considered different selection processes (contactability and participation) from the gross sample to the net sample at both the household and the individual level and adjusted to known population distributions with regard to socio-demographic structure (age and gender distribution, socio-demographic status, residential area, and migration history) (13).…”

Estimating actual SARS-CoV-2 infections from secondary data

“…For the occurrence of the Omicron variant, there are no specific prevalence/seroprevalence studies available for Austria. However, a nationwide seroprevalence study in Germany in the period from November 2021 to February 2022 Bartig et al [30] evaluates the prevalence ratio as 1.5 to 2 (RKI, 2022). We assume that this ratio also holds for Austria and is likewise representative as a mean value for the later stage of the pandemic, i.e.…”