Are Schools Ready to Reopen?

Children and COVID-19: Is it Safe to Reopen Schools?

    Since the first outbreak of coronavirus in the U.S early this year, schools have gradually shut down and moved to online education. Government officials believed that it was safer for students to participate in distance learning as opposed to learning in a crowded classroom. However, children are the least likely to become infected with COVID-19 as previous research has shown that coronavirus susceptibility and severity increases with age. (See Who's at Risk) A new study published on June 16, 2020 in Nature Medicine, investigates the effect of COVID-19 in children and provides useful information on how safe it is for schools to reopen. 

   Risk of Infection

    Children and teens are known to be less likely to develop COVID-19 infections but how much lower is their risk of infection compared to the older population? Age-based COVID-19 transmission models were created using existing data from China, Italy, Japan, Singapore, Canada and South Korea. Based on the results, researchers from the study estimate that those aged under 20 are at half the risk for COVID-19 infection compared to those aged over 20. Additionally, even if those aged under 20 do become infected, they are unlikely to show symptoms of coronavirus. According to the results from this study, 79% of individuals aged 10-19 with COVID-19 infections were found to be asymptomatic while only 31% of individuals aged over 70 years were asymptomatic.  

Effect of School Closures

    Many schools have shut down due to the difficulty of maintaining social distancing in crowded settings like a classroom. But how effective are school closures in stopping the spread of the virus? To see what effect school closures had on the spread of the virus, researchers created a simulation of influenza and COVID-19 outbreaks in three cities with varying demographics: Milan, Italy (median age 43), Birmingham, UK (median age 30) and Bulawayo, Zimbabwe (median age 15). In their simulation, researchers recorded the amount of COVID-19 and influenza cases while schools were open, compared the amount of cases during school closures. As predicted, Milan, with the highest median age population, had a higher amount of clinical cases compared to the younger age distribution of cases in Zimbabwe. The results also indicated that while influenza rates decreased drastically after school closures, COVID-19 cases were not as affected by school closures. In all three cities, COVID-19 had many more cases than the influenza virus even after school closures. During school closures, the average rate of cases across all three cities for COVID-19 was 0.287% while the averages rate of cases for influenza was 0.023%. Compared to influenza, COVID-19 was found to have a similar distribution of cases but on a much larger scale.

  

 Why are there less COVID-19 cases in children

    The authors conducted a simulation of COVID-19 infection across 146 capital cities with varying age demographics. cities with younger populations had fewer cases compared to cities with older populations. However, it is unclear whether the fewer confirmed cases in children are due to fewer young people catching the virus or fewer showing symptoms of the virus. It's anticipated that part of the reason why there are less COVID-19 cases in cities with a large number of children is because children are likely to be asymptomatic, or show little/no symptoms, even if they do carry the virus.

    Conclusion

    Children/teens aged under 20 are at a much lower risk of COVID-19 infection than those aged over 20. Out of those infected, the younger population showed less severe symptoms and were more likely to be asymptomatic. School closures were also found to have a minimal effect on stopping the spread of the coronavirus compared to other respiratory infections.

Sources

1. Davies, N.G., Klepac, P., Liu, Y. et al. Age-dependent effects in the transmission and control of COVID-19 epidemics. Nat Med (2020). https://doi.org/10.1038/s41591-020-0962-9