Coronavirus: London shuts down 40 tube stations

London shut down 40 tube stations in an effort to combat the spread of coronavirus, according to media reports.

The move comes as the United Kingdom ramps up its efforts to combat coronavirus, having previously resisted calls to implement stringent lockdown measures.

On the same day the country's defense ministry announced up to 20,000 military personnel would be put on standby in preparation to combat the virus.

Read more:

The UK response to coronavirus: ‘Herd immunity’ and its risks explained

Coronavirus lockdown in London? UK’s Johnson says ‘we will rule nothing out’

UK Prime Minister Boris Johnson refused to rule out lockdown measures on Thursday.

“We’ve always said we’re going to do the right measures at the right time,” he said.

“A lot of people are making a real heroic effort to comply with the advice we’ve given, but as I’ve said ... we keep everything under continuous review.”

Is the UK changing its approach?

The UK initially did not follow other countries and rushed to contain the virus using all means necessary. In contrast to other countries such as Italy and France, schools remained opened, and public gatherings permitted.

The aim of the strategy was to spread out the peak of the virus, ensuring that it did not spike at once, and to ensure that the population became immune to it in the long run.

Sir Patrick Vallance, the chief scientific adviser to the government, told Sky News last week that the UK’s strategy was to “suppress” the virus rather than completely “get rid of it” – a long-term strategy in which a certain amount of the population is allowed to contract the disease once to build immunity to it a second time.

The strategy outlined by Vallance is known as building “herd immunity.”

Human bodies fight infectious diseases through their immune systems, which often retain a immunological memory of a disease once they recover from it, allowing it to better fight off the disease when coming into contact with it again in the future.

Herd immunity refers to the state in which the majority of the population – the herd – has contracted and survived a disease, and is therefore immune to contracting and spreading it a second time.

However, the strategy has significant risks. The major problem with trying to achieve herd immunity is that tolerating the spread of the disease will inevitably infect and kill a significant part of the population, which could potentially be avoided by containing the disease.

Of the 40 million people that Vallance said would need to contract the disease for the UK to achieve herd immunity, around 80 percent or 32 million are expected to experience only mild symptoms. However, this still leaves the remaining 8 million with severe symptoms. Even with a low mortality rate, at least 300,000 people could die.

With the latest measures, it now seems that the UK government is moving towards more of a lockdown strategy, aimed at limiting human contact when possible.