Covid: Can a “circuit break” stop the second wave?


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Prime Minister Boris Johnson said the UK is now ‘seeing a second wave’ of Covid-19.

The expansion of ‘local’ restrictions means that more than 13 million people (a fifth of the UK population) have additional brakes on their lives.

And the outbreak of cases is not contained only in hot spots, but is widespread across the UK. Local restrictions do not remove a virus that spreads outside of these areas.

It is in this context that the government decides what to do next. One idea is a “blackout” – a short, abrupt period of tightened restrictions for everyone to curb the spread of the coronavirus.

So why would a blackout be necessary and what could it accomplish?

Let’s do some rough calculations.

Take 6,000 cases a day, double them every week – as the Scientific Advisory Group for Emergencies (Sage) suggests – and by mid-October you have over 100,000 infections a day, like we did at the top.

It is not a fancy modeling of the disease, it is not set in stone and measures such as the “rule of six” should slow the spread.

But that simple sum gives an idea of ​​how quickly a small problem can turn into a huge problem.

A circuit cut consists of trying to change this trajectory.

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Media legendBoris Johnson: “We must ask ourselves whether we should go further than the rule of six”

“The evidence is that hospitalizations are increasing, it’s a worry and the concern is what happens if we don’t do anything,” Dr Mike Tildesley of the University of Warwick told me.

He’s part of the government disease modeling group of scientists called SPI-M who discussed circuit breakers this week.

Dr Tildesley added: “To be perfectly frank, neither of us want this, but we’re stuck between a rock and a hard place.

“However, with a short-term managed foreclosure you save yourself time. ”

An episode of tighter restrictions is expected to lead to a drop in cases rather than an increase, but the extent to which they drop is uncertain and will depend on the severity of the restrictions.

It is suggested that schools and workplaces would remain open, but the hospitality sector (think bars and restaurants) would be affected. It’s not Lockdown 2.0.

“The overarching goal is that you don’t want the intensive care units to fill up again, but you also have more options at lower levels of the virus,” said Dr Adam Kucharski, another SPI member. -M and researcher at the London School of Hygiene and Tropical Medicine.

When virus levels are low, it is easier to spot outbreaks and use highly targeted measures, less disruptive than national ones, to curb the spread of Covid-19.

Dr Kucharski told the BBC: “As cases and hospitalizations increase, there is less information about what the epidemic is doing because Test and Trace can’t detect everything, you don’t know where it is. find the epidemic.

“That’s the difference, the options decrease dramatically as the cases increase. “

Circuit cuts have been used in other countries. The temporary lockdown in New Zealand can be seen as a blackout that gave contact tracers time to get their outbreak under control.

In the UK, a break could buy time to improve the government’s beleaguered testing and tracing program, which is already grappling with current levels of coronavirus.

But the problem is, once the blackout was over, the cases would start to rise again.

“You can find yourself in a cycle of short-term shutdowns until you have an exit strategy like a vaccine or herd immunity,” says Dr. Tildesley.

Remember, it’s only September.

Spring, when the coronavirus should be easier to contain and we could have a vaccine, is still a long way off.

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