Coronavirus locking: how to lift restrictions?

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When can I see my family? Do you have friends? Have an evening? A holiday? Or even go back to work? When can children go back to school?

The blockages have been essential to contain the spread of the coronavirus, but they are causing enormous disruption and distress in life around the world.

So when can they be lifted?

Governments have to make big decisions – when to act, what restrictions to lift, how to contain the virus instead, and how to balance saving lives today with long-term damage to society.

It’s going to be a long journey – don’t think it’ll all be over in a few weeks.

“Basically we have a lot of not-so-good options, it won’t be a day and everything will change, but things could open up,” Dr Adam Kucharski of the London School of Hygiene and Tropical told the BBC Medicine. .

  • When will the epidemic end and life return to normal?

Why can’t we just lift the lock?

We cannot just go back to normal after the peak of cases or even after they are reduced to very low levels.

The best estimate of the proportion of infected (and potentially immune) people in the UK is only 4%. In other words, more than 63 million people are still vulnerable to infection.

If we just lift the lock, another explosive outbreak is inevitable.

The fundamentals of the virus have not changed either – one infected person will pass it on, without locking, to three others on average.

Reducing these infections by 60 to 70% is what it takes to reduce cases. For the moment, that means cutting our human contact by that amount.

If we lift the social distancing measures, then something else has to happen to remove the virus instead or at least prevent people from ending up in intensive care.

Flexibility?

There can be easy gains if countries already reduce infections by more than 70%.

“There is evidence that many locked out countries have exceeded this, in China, it is 80-90%,” said Dr. Kucharski.

A high number now makes it possible to quickly classify cases.

But it is also an opportunity to lift some of the current restrictions without causing a spike in cases.

China, particularly in the epicenter of the pandemic – Wuhan, has experienced a severe and prolonged lockdown, including the closure of public transportation. It is not yet known how much leeway other countries may or may not have.

Why don’t we have more tests?

The massive increase in virus detection tests allows for a strategy called “find and destroy.”

You identify the cases. Test anyone with whom they have come into contact. And isolate them before they become infectious.

It is remarkably similar to the approach taken at the start of the outbreak when there were relatively few imported cases chased.

Do it successfully enough and it will reduce the virus’s ability to spread and mean that we don’t need such a strict set of restrictions on daily life.

“At the moment, it takes, on average, a 60 to 70 percent reduction in social interactions to stop the increase in the epidemic,” said Dr. Kucharski.

“If we can bring it down to 30%, it gives you a lot more to play with. “

But even massive testing is not normal life.

You would need other measures to control the disease and these should be maintained over the long term as the fundamentals (a spreading virus and a vulnerable population) would not change.

“This is a more moderate version of our current situation,” said Dr. Kucharski.

It is also intensive work that must be done quickly to stay one step ahead of the infection (this is where we talk about a smartphone application to identify cases) and the method is the most viable when cases are at low levels.

  • UK plans virus detection app to help lockdown

What about protecting people at risk?

Another strategy is called “improved armor”.

Instead of trying to remove the coronavirus from all walks of life, you could aim to stop it altogether for those most at risk.

Age and other medical conditions significantly increase the risk of death from Covid-19.

Lockdown keeps critical care units from being overwhelmed, but ensuring that vulnerable groups are not infected could achieve the same goal even if cases spread more widely among young and healthy people.

Professor Mark Woolhouse of the University of Edinburgh said: “Very roughly, for 80% of us who are not vulnerable, it is a nasty virus, it is certainly a serious health problem, but that would not overwhelm the health care system and not lock up society.

“If we really strengthen this shielding, if we make a very strong shield, it allows you to buy a lot more space and it can mean that you can relax certain measures permanently. “

We are already protecting vulnerable people and asking them to stay at home for 12 weeks.

The improvement could mean that all staff in hospitals, nursing homes or anyone visiting the elderly undergo regular testing to make sure they are free from the virus. Ideally, antibody tests would show that they are immune to it.

The danger of having more viruses circulating in the community may be more difficult to control and then these “shields” will be under intense pressure.

What locking measures could be lifted?

Some restrictions have less effect on the virus than others.

“There are certain interactions and activities that are overall less risky,” said Dr. Kucharski.

He argues that the lifting of different restrictions can be classified into three broad categories – those that pose a low, moderate and substantial risk of increasing the transmission of the virus.

Low risk includes outdoor exercise, which has been restricted in some countries.

Moderate would include the reopening of some non-essential stores or occasional meetings with people outside the household.

Substantial increases could come from the lifting of advice on working at home, the reopening of schools or the isolation of sick people and the quarantine of households.

“I think the order in which things are entered will be reflected in the order in which things are lifted,” he said.

But the measures to be lifted will constitute a difficult balance. It should be a combination of social and economic benefits versus the impact on the spread of the virus.

Professor Neil Ferguson of Imperial College London said: “We want to find a set of policies that keep the virus removed

“Without a doubt, the measures will probably be targeted by age, by geography and we will have to introduce higher test levels at community level in my opinion to really isolate the cases more effectively and identify where transmission occurs.” “

Immunity passports?

The idea of ​​passports or immunity certificates is always around – if you’ve had the disease, you have a test and if you have antibodies that can kill the virus, then you can go about your daily business.

However, there are a number of scientific challenges.

We do not have a specific antibody test. We do not know how long the immunity could last. And we don’t know that even if antibodies stop you from getting sick, they are enough to stop you from harboring the virus and spreading it to others.

When and where to lift?

Professor Ferguson suggested that the measures could start to be lifted by the end of May.

But there is also a decision on how far we go with removing the virus after we get past the peak.

We could lower the levels as low as possible and this will greatly limit the ability of the virus to rebound in a second wave. But the compromise keeps the lock on longer.

Or we could leave the lock earlier and accept a higher number of cases, which creates its own problems.

There is also a decision on whether to maintain a UK-wide approach to lift the foreclosure or whether the measures could vary regionally, or even within cities, to focus on where epidemics occur.

What could change the balance?

The biggest thing that could happen is a vaccine – if people were vaccinated, there would be no need for social distancing. We think it’s over a year away.

If a vaccine doesn’t show up (people have hope, but it needs development at unprecedented speed), the concept of collective immunity can come into effect.

This would happen when so many people have been infected (up to 70% of the population) that the virus can no longer cause large epidemics.

Effective drugs would also make a huge difference. If they could prevent Covid-19 from going from a cough or fever to a serious illness requiring intensive care, then having a large number of cases would be less of a problem. Again, we are awaiting the results of the clinical trials.

  • Are we getting closer to a vaccine or medication?
  • When will the epidemic end and life return to normal?

We could get closer to normality, or at least normality for some, in the coming months. But we are all still in the long run.

Follow James on Twitter.



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