Table 2. Proportion of pupils with SARS-CoV-2 antibodies by class and by primary school in a city in northern France, 13 January–19 April 2020 (n = 510).
| School | Class and proportion of pupils with SARS-CoV-2 antibodies | All classes | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| CP | CP/CE1a | CE1 | CE1/CE2a | CE2 | CE2/CM1a | CM1 | CM1/CM2a | CM2 | |||
| Proportion | Proportion | Proportion | Proportion | Proportion | Proportion | Proportion | Proportion | Proportion | Proportion | % | |
| A | 1/7 | 0/8 | 0/7 | NA | 0/9 | NA | 0/10 | 1/12 | 0/8 | 2/61 | 3.3 |
| B | 2/17 | 0/1 | NA | 1/32 | NA | 3/18 | NA | 5/22 | NA | 11/90 | 12.2 |
| C | 0/12 | NA | 3/10 | NA | 1/14 | NA | NA | 10/32 | NA | 14/68 | 20.6 |
| D | 0/8 | 0/8 | 1/13 | 0/9 | 1/11 | NA | 1/24 | 0/1 | 1/12 | 4/87b | 4.6 |
| E | 0/12 | 2/28 | NA | 0/9 | 2/15 | NA | 2/15 | 0/25 | 0/13 | 6/117 | 5.1 |
| F | 0/16 | NA | 1/11 | NA | 2/18 | NA | 4/22 | NA | 1/20 | 8/87 | 9.2 |
CE1: cours élémentaire première année; CE2: cours élémentaire deuxième année; CM1: cours moyen première année; CM2: cours moyen deuxième année; CP: cours préparatoire; NA: not applicable (the school in question had few pupils so there were no children populating the class in question); SARS-CoV-2: severe acute respiratory syndrome coronavirus 2.
The classes CP, CE1, CE2, CM1, CM2 respectively correspond to the first to fifth years (levels) of primary school. Shaded areas: classes with one documented symptomatic introduction.
a These are classes combining two levels.
b Class missing for one child.