What science says about the blockade of coronavirus “circuit breakers” and whether they work

Introducing a short and sharp “circuit breaker” of national regulations to slow the spread of COVID-19 It is at the center of a public debate on how to tackle the virus.

Scientists, teachers, and politicians have endorsed this concept as an important means of curbing an ongoing epidemic, but the timing and effectiveness of it remains questionable.

Wales protects two weeks of “firebreak” blockade NHS From being overwhelmed by the resurrection of Coronavirus Said the prime minister, saving lives.

Mark Drakeford has urged the country to “join” and “play our part in a common effort” in its latest action, which will take effect on Friday at 6 pm.

The restriction that people are required to stay at home and non-essential businesses such as pubs and shops will be closed will continue until November 9.

Now, Boris Johnson There is pressure to implement similar measures in the United Kingdom.

Here are some of the important issues being discussed by experts.

Difficulty in collecting evidence

One of the challenges facing scientists is to establish sufficient evidence to determine the effectiveness and harm of imposing further restrictions on the coronavirus.

According to a document issued this month, the blockade of circuit breakers was at the top of the list of candidates for intervention recommended by the government by the Emergency Science Advisory Group (Sage) in September.

However, sage experts acknowledged that the evidence base for the effects of intervention packages was “weak,” noting that the data were “often observational” and supplemented by modeled estimates.

Load video

Video not available

Click to play
Tap to play

The video will play automatically soon8Cancel

Play now

They have difficulty predicting how well people will comply with new measures, delaying interventions to uncover the impact on case numbers, and determining what would happen in the future without a circuit breaker. I explained that it would result from this.

Professor Graham Rooms, a behavioral scientist at Warwick Business School, said the Sage document included elements such as hospital infection control, ongoing “face, space, and hygiene” measures, international travel management, and NHS testing and tracing. He said he did not consider it.

“There was another major consideration that was’out of range’. That is, it is a serious attempt to quantify the damage to work, income, business, mental health and other health, social life and civil liberties, “he insisted.

What modeling suggests

The modeling presented to the Scientific Pandemic Influenza Group (SPI-M) on Modeling Advising the Ministry of Health could reduce the remaining coronavirus deaths this year from 19,900 to 12,100 if a circuit breaker is imposed. It suggests that you can do it. Hospitalization was reduced from 132,400 to 66,500.

If school It turns out that the store remains open and the death toll could drop to 15,600.

Graham Medley, a professor of infectious disease modeling at the London School of Economics and Tropical Medicine and Sage, one of the authors of the paper, said circuit breakers could only “kick a can” by delaying death until late 2021. I admitted that there is.

However, Professor Medley said the NHS would definitely save lives by not overloading and being able to provide other routine care.

Timing issues

SPI-M recommended imposing a blockade in the United Kingdom from October 24th. This happens at the same time as school. half period And it helps limit further confusion to the child’s education.

Professor Medley argued that it was likely too late for a circuit breaker in October, but December is an option, giving people and businesses time to prepare.

The pre-planned aspect of the circuit breaker is considered one of the strengths of the concept.

Liam Smyth, a professor of clinical epidemiology at the London School of Economics and Tropical Medicine, previously stated:

“In addition, it will reduce the need for last-minute policy changes that people find very destructive and confusing.”

Multiple circuit breaks?

The circuit breaker description focuses on a 2-3 week load to reduce the forward transmission rate, which is represented by the “R” value.

However, Sage acknowledges that multiple circuit breaks may be required to keep the case level low.

Paul Hunter, a professor of medicine at the University of East Anglia’s Norwich School of Medicine, said that if such a temporary measure reduced the current Covid-19 case’s increase of 6% per day to just 3%, the country would “It will return to the square about a week after the circuit breaker is over.”

“To keep the case numbers constant at the current level, we need to install a circuit breaker for a couple of weeks each month, all other things being equal,” he added.

He acknowledged that the potential improvements in NHS Test and Trace and the advent of effective vaccines have brought more value to short-term circuit breakers.

“Otherwise, is it better to have one blockade for the next six weeks or three two-week blockades over the next three months?” Asked Professor Hunter.

Use a circuit breaker

Scientists warn that short-term circuit breakers may have only temporary effects unless supportive measures are taken.

Sage argues that two weeks of rigorous action could set the epidemic back for more than about 28 days, but cases could increase again as regulations and behavior return to pre-circuit break levels. There is sex.

The need to supplement the measures was emphasized by one senior source who stated that existing measures were “frankly useless” and not sufficient where the number of cases was increasing rapidly.

Jonathan Ball, a professor of molecular virology at the University of Nottingham, said: “It’s clear that outbreaks need to be interrupted in order to give time for other interventions, especially those related to testing and contact tracing, to work.”

If this was not done, the country risked a “flip-flop between blockade and mitigation,” he warned.

Learn from abroad

Israel has relaxed its coronavirus restrictions this week after a month-long blockade.

The country has recorded more than 303,000 infections since the beginning of the Covid-19 pandemic, killing more than 2,200 and recovering 272,000.

Although daily infections have been reported to have decreased, there are still restrictions, including meetings that are limited to 20 people outdoors and 10 people indoors.

New Zealand’s one-month blockade imposed on March 26 rapidly curtailed the case and the country was praised for its effectiveness.

On April 18, New Zealand recorded 13 new cases, but there were no double-digit days until August 12.

Public compliance

Scientists warn that the success of circuit breakers depends on the public’s willingness to comply with the new rules.

According to a YouGov survey released last week, 54% said the government felt that the government should introduce a blockade in September, but only 28% of 4,222 adults opposed it.

One of the problems pointed out by experts is that there is a gap of about 10 or 14 days before the impact of new measures can be seen on infection rates.

One senior source said the population needed to be able to confirm that it was possible to reverse the increase in cases.