Anti-SARS-CoV-2 IgG antibodies in adolescent students and their teachers in Saxony, Germany (SchoolCoviDD19): very low seropraevalence and transmission rates

Abstract

Background: School closures are part of the SARS-CoV-2 pandemic control measures in many countries, based on the assumption that children play a similar role in transmitting SARS-CoV-2 as they do in transmitting influenza. We therefore performed a SARS-CoV-2 seropraevalence-study in students and teachers to assess their role in the SARS-CoV-2 transmission. Methods: Students grade 8-11 and their teachers in 13 secondary schools in eastern Saxony, Germany, were invited to participate in the SchoolCoviDD19 study. Blood samples were collected between May 25th and June 30th, 2020. Anti-SARS-CoV-2 IgG were assed using chemiluminescence immunoassay technology and all samples with a positive or equivocal test result were re-tested with two additional serological tests. Findings: 1538 students and 507 teachers participated in this study. The seropraevalence for SARS-CoV-2 was 0.6%. Even in schools with reported Covid-19 cases before the Lockdown of March 13th no clusters could be identified. 23/24 participants with a household history of COVID-91 were seronegative. By using a combination of three different immunoassays we could exclude 16 participants with a positive or equivocal results after initial testing. Interpretation: Students and teachers do not play a crucial role in driving the SARS-CoV-2 pandemic in a low prevalence setting. Transmission in families occurs very infrequently, and the number of unreported cases is low in this age group, making school closures not appear appropriate as a strategy in this low prevalence settings. Funding: This study was supported by a grant from the state of Saxony

What is the evidence for transmission of COVID-19 by children in schools? A living systematic review

“…The initial search retrieved 2,178 articles. After screening, 11 studies were eligible for inclusion ( Figure 1), including five cohort studies [13][14][15][16][17] and six cross-sectional studies [18][19][20][21][22][23]. We did not identify viral genotyping studies.…”

“…Cross-sectional studies estimated the proportion of SARS-CoV-2 positive cases, to give an insight into how many people have been infected in schools. As described above, the positivity results in the general study population under school environment varied from 0.00 (lowest in eight daycare centers in Belgium) to 25.87% (highest in one high school in France), which is likely to reflect the community positivity rate at the time the study was conducted [18][19][20][21][22][23]. The lower positivity rate in students suggested that students are less susceptible to infection and/or less frequently infected than adult school staff, which indicated that students are not at higher risk of causing super-spreading events in schools.…”

“…Four studies in Chile (Vitacura, Santiago), Germany (Saxony), and France (Crépy-en-Valois) identified antibody positive cases in schools, and overall seroprevalence varied from 0.01% to 25.87% [19][20][22][23].…”

“…After reopening of schools in Germany (Saxony) on 18 May, 1,538 students from grade 8-11 and 507 teachers in 13 secondary schools were tested for SARS-CoV-2 antibody to investigate their role in SARS-CoV-2 transmission in schools [20]. The overall antibody positive rate was 0.58% (12/2045), and 0.72% (11/1538) for student and 0.20% (1/507) for school staff.…”

“…We also meta-analyzed SARS-CoV-2 positivity rates in schools (Table 4) from a total of six cross-sectional studies which included 639 SARS-CoV-2 positive cases in 6,682 participants tested [18][19][20][21][22][23]. The result of the random effect meta-analysis showed that the pooled SARS-CoV-2 positivity rate of total study participants was 8.00% (95% CI: 2.17%-16.95%) with substantial heterogeneity (I 2 = 99.2%) ( Figure 5A), but no evidence of publication bias ( Figure 5B, 5C).…”