16.000 health professionals have made an appeal to the Belgian government to exempt children in kindergarten and elementary school from social distancing rules. In addition, they see no rationale for reduced class sizes. In their view, the negative effects of denying physical contact to children will be significantly larger.
Their claims are based on the assumption that children are hardly a factor in spreading the virus. However, this assumption is being challenged by recent research. German researchers have found that children may be as infectious as adults, as the very young carry similarly high virus loads as adults.
A study on data from Wuhan and Shanghai revealed that children between 0 and 14 years are less susceptible to infection than adults, but this is outweighed by the larger number of contacts of children. Opening schools risks to increase the reproduction number by 0.3.
Similar findings were reported in Germany. Work quantifying the various measures taken by the government indicated that closing of schools and childcare centers had reduced the growth rate of infections from 30% to 12%. Not negligible therefore.
A comment of epidemiologist Bill Hanage in the New York Times probably sums it all up: assumptions that children are not involved in the epidemiology can have disastrous consequences.