From December 2020 to Januari 2021, 12.4% of the pupils and 14.8% of the school staff in primary school and in the first grade of secondary education in Belgium had antibodies against the coronavirus. These results are comparable to the findings in the general population. This is shown in a study by Sciensano in collaboration with the Catholic University of Leuven. The study lasts until the end of the school year and follows the evolution of the number of antibodies against SARS-CoV-2 in pupils and school staff.
During the first testing period, which took place from December 3, 2020 to Januari 28, 2021, a sample of 1.285 pupils and 818 school employees in 44 primary schools and 40 secondary schools were tested. This sample is representative of all pupils and school staff in Belgium.
The results from the first testing period show that slightly fewer children have antibodies than school staff (12.4% of the students and 14.8% of the school staff). The differences between primary and secondary school pupils and school staff are minor and not statistically significant. According to results of a survey accompanying the study, only 2% of the pupils and 10% of the staff tested positive for COVID-19 before the study. No one in the sample has yet been hospitalized for COVID-19.
Regional differences
There are regional differences in the presence of antibodies among students and school staff. This confirms what we saw earlier in blood donors and primary care providers:
- Brussels: 24% among pupils, 10.5% among school staff
- Flanders: 8.7% among pupils, 13.2% among school staff
- Wallonia: 15.4% among pupils, 17.7% among school staff
These differences reflect the regional epidemiological situation during the second wave in Belgium, which mainly affected Brussels and Wallonia. The numbers for Brussels are based on a small number of pupils and staff members and therefore have a high statistical uncertainty. More data will be available for this region in the following testing periods.
Results similar to those in the general population and health care providers
We conclude that in the period from December 2020 to Januari 2021, the percentage of schoolchildren and school staff with antibodies against SARS-CoV-2 is in line with the percentage of antibodies found in the general Belgian population and among primary care providers. Our study shows no evidence that schools are place where the virus speads more or is more likely to spread that elsewhere in the community.
The same group of pupils and staff were tested a second time in March. A third test moment is planned from mid-May to mid-June this year. The results of these testing periods will follow later.