Summary List Placement
Scientists are often quick to remind the public: no model is perfect.
After Professor Neil Ferguson’s computer model suggested in March that 500,000 people in the UK would die of the coronavirus without lockdown measures, the UK quickly abandoned its herd immunity strategy and resorted to shutting down schools and businesses.
A June review in the journal Nature showed that some researchers were able to reproduce Ferguson’s findings, but software engineers said the code was messy and some public-health experts said the results were unreliable.
One finding in particular didn’t seem to make sense: The model showed that closing UK schools and universities during a lockdown actually led to more COVID-19 deaths than if schools had stayed open.
A new peer-reviewed report published in the BMJ on Wednesday suggests that takeaway could be accurate.
“Our first thought was that it was a mistake, but after a little work on the code, we replicated the result,” Graeme Ackland, the study’s author, wrote. “The basic explanation for this counter-intuitive result is that an intervention that substantially suppresses the first wave of the epidemic leads to a stronger second wave once the interventions are lifted.”
Other experts still aren’t convinced.
“This result applies to a specific, and probably unrealistic, scenario and should not be interpreted as a prediction,” Mark Woolhouse, a professor of infectious disease epidemiology at the University of Edinburgh, said in a statement.
The model assumes that people behave a certain way during lockdown: namely, that suspected cases isolate at home, households voluntarily quarantine, and people over 70 years of age distance themselves from others. That latter measure has proven difficult to enforce, experts say.
“Many of the most vulnerable require the care of other members of the population,” Matt Keeling, a professor of populations and disease at the University of Warwick, said in a statement. “While it is easy to switch off this component in a model, achieving this is practice is far more difficult.”
Under all of the model’s scenarios, lockdown measures are completely lifted after three months. The model also assumes that lockdowns will be lifted before an effective vaccine becomes available.
“This gives rise to a strange set of scenarios where a second wave is allowed to progress in an uncontrolled manner,” Keeling said.
Indeed, Ackland acknowledged that “the result only holds if there’s no successful vaccination program for a couple of years.”
Infections could peak after schools reopen
There’s an inherent logic to shutting down schools during the pandemic: Fewer interactions mean fewer opportunities for the virus to transmit from one person to the next.
A July study found that closing US schools in the spring may have been associated with 1.37 million fewer cases over a 26-day period and 40,600 fewer deaths over a 16-day period. Surveys conducted in Wuhan and Shanghai also found that closing schools reduced peak infections in those cities by up to 60%.
The UK model doesn’t deny that school closures can lower transmission. But it suggests that …read more
Source:: Business Insider