Among the 431 students enrolled in high school at ONM school, an average of 32,5% of students attended classes daily for five hours in person during the test period. The total number of participants in the study was 200 individuals, 59 employees (28 professors) and 141 students (Fig. 1).
Approximately 47 employees fully completed the initial questionnaire (80%); all were fully vaccinated (at least two weeks of second doses); 25 received Coronavac, 18 Astrazeneca and 4 Pfizer. Among students, 97 completed the initial questionnaire (69%), 87 received the first dose of Pfizer, 4 of Coronavac, and 3 of Astrazeneca.
The median age of the students in the study was 16 years old, while the median age of employees was 47 years old. Most of the participants were female (55.5%). Thirty participants reported comorbidities (40% students and 60% employees) (table 1).
A total of 969 samples were tested, and the mean of testing was 108 tests per week (covering approximately 54% of individuals who agreed to participate in the study). During the study period, 322 symptomatic patients were tested by SCS public care municipality, and 40% of them were positive for COVID-19. Despite the presence of the virus in the municipality of SCS, none of the asymptomatic participants involved in the study tested positive for COVID-19 (Fig. 2).
At the 4th week of the study, one teacher had symptoms (October 20th). She was referred to a primary care clinic, and the RT-PCR test was positive for COVID-19. Simultaneously, 18 employees (9 collaborators and 9 professors) who had contact with the teacher during the previous days were tested for COVID-19, and all presented negative results.