Closing the schools in mid-March has had much less effect on slowing down the spread of the coronavirus than other measures including hand hygiene and social distancing, according to a report by biostatistician Niel Hens.
Hens is professor of biostatistics at the universities of Hasselt and Antwerp, and an expert in using mathematical models to predict the progress of infections in the population.
“I’m a mathematician by training,” he told the VRT programme De Zevende Dag. “During my PhD I transformed into a biostatistician. For the last 15 years I’ve been working on mathematical models of infectious diseases, to better map the spread of such diseases.”
Professor Hens’ expertise is in bog demand, and he has been called on to advise the government on how to proceed now that an exit strategy from the lockdown is on the agenda.
Not that the government necessarily takes expert advice. In the beginning of the crisis, virologists like Professor Marc Van Ranst advised against closing the schools.
“We should never have closed the schools,” he told VTM back in March. “I was counting on [schoolchildren] for group immunity. The more children were infected, the fewer sick people we would see when the coronavirus flares up again.”
Now the mathematics behind Prof Hens’ model have shown the effect of closing the schools. That measure accounts for only 5% of the slow-down effect on the spread of the virus.
By comparison, the general lockdown – closure of most shops, all restaurants and bars, teleworking and restrictions on travel – account for 25% of the effect. And the simplest of all measures, hand hygiene and social distancing – account for 40% of the effect.
The results will go towards determining policy, perhaps not this time around, but when the virus makes a reappearance later, as experts fully expect it to do.
“The challenge with Covid-19 is that it’s an infectious disease [whose progress] is determined by human behaviour,” he said. “And mapping human behaviour is enormously complex.”