The research found neither teachers nor their household members were at increased risk of hospital admission with Covid or severe Covid at any time during the previous academic year, when compared with similar working age adults.
The findings were led by the University of Glasgow in collaboration with Public Health Scotland and published in the British Medical Journal.
The results are based on Scottish data from March 2020 to July this year, covered periods when schools were fully open, and also when they were fully or partially closed. In the latter period of time covered by the study, the Delta variant was already circulating in the population.
After adjusting for factors such as age, sex, ethnicity, underlying medical conditions and deprivation, the results show in the initial period of school closure in spring 2020, the risk of hospital admission with Covid was around 50 per cent lower in teachers and their household members than in the general population.
In contrast, during this same period, the risk was almost four times higher in patient-facing healthcare workers and almost twice as high in their household members. Similar figures were shown for the period of the second school closure in winter 2020.
In the first period of full school opening in last year’s autumn term, the risk of hospital admission in teachers increased by around 2.4-fold, reaching a similar level to that in the general population. In the summer term of 2021, when schools were also open and vaccination of the Scottish population was underway, a smaller increase of around 1.7-fold was seen.
The study also found both teachers and their household members were not at higher risk of severe Covid – admission to ICU or death - at any time in the 2020/21 study period. The overall risk of hospital admission with Covid remained less than 1 per cent for teachers, healthcare workers, and adults of working age in the general population.
David McAllister, professor of clinical epidemiology and medical informatics at the University of Glasgow and lead author of the study, said it was not possible to say why when schools were mostly closed, teachers had a lower risk of hospitalisation.
He said: “What we can say, is that while schools were open, teacher’s risk of hospitalisation with Covid-19 was about average when compared to that of other working-age people in Scotland who were similar in terms of age, sex, and known underlying medical conditions.
"This was also true during the recent spike of infections due to the Delta variant which occurred when schools were fully open. Together with the finding that teachers were at lower risk of severe Covid-19, and that people who shared a household with teachers were not at increased risk, this is likely to be broadly reassuring for people involved in face-to-face teaching.
“It is important to note that during the period where the Delta variant was circulating, uptake of vaccination among teachers was high, and we would continue to encourage everyone offered a vaccine to take this up.”
Most teachers were young, with an average age of 42, 80 per cent were women, and 84 per cent had no existing conditions.