Boris Johnson vows to have a test and trace system ready on Thursday

January 31: First confirmed cases in the UK are two Chinese nationals staying in York. 

February 1: China reports asymptomatic cases of coronavirus. 

February 21: Government experts conclude at a meeting that the disease is still only a ‘moderate’ threat to the UK. 

March 12: The UK shelves efforts to test and ‘contact trace’ everyone with symptoms on March 12, as the government’s response moves from ‘containment’ into a ‘delay’ phase.

Instead people who think they have the illness are urged to self-isolate unless their conditions became so severe they need medical help. 

Chief Medical Officer Chris Whitty said: ‘It is no longer needed to identify every case, so we will pivot testing capacity to identify people in hospitals with symptoms to ensure they don’t pass it on.’

March 13: Chief Scientific Officer Patrick Vallance suggests the strategy is not to ‘suppress’ coronavirus completely but ‘reduce the peak’ as up to 60 per cent get infected. He says that means the UK will ‘build up some kind of herd immunity so more people are immune to this disease’. 

March 16: Boris Johnson urges Britons to follow ‘social distancing’ guidelines as well as isolating when they have symptoms, in a change of policy after modelling found the death toll could be much higher than previously estimated. 

March 17: Patrick Vallance tells a Commons committee testing numbers should be higher. ‘I think we need a big increase in testing, and that is what I am pushing for very hard.’ 

March 18: Amid growing criticism, the PM declares that there will be a big expansion of tests from under 5,000 a day to 25,000. He also sets an ambition of 250,000 tests a day, although this includes potential mass antibody tests for whether people previously had the disease.

March 21: Downing Street sends an email to research institutions begging for machines needed to process testing samples. No10 denies this was the first time it had raised the idea. 

March 27: Mr Johnson and Matt Hancock announce they have tested positive for coronavirus. Prof Whitty goes into self-isolation with symptoms.  

March 29: Cabinet ministers Matt Hancock and Michael Gove hail news that the UK is now carrying out 10,000 tests a day. 

April 1: It emerges the UK has still not carried out 10,000 tests in a day, despite apparently having the capacity to do so.

April 2: Matt Hancock sets a target of 100,000 tests a day by the end of the month. At the same time a goal of 25,000 tests a day by the middle of April is quietly dropped.

April 5: The PM’s official account causes confusion by tweeting that the target is for 100,000 people to be tested a day, rather than 100,000 tests as other ministers have suggested.

Many people need more than one test in a day for clinical reasons, such as to confirm results. 

April 6: Mr Johnson is admitted to hospital as his symptoms fail to subside. 

April 30: Mr Hancock declares victory with 122,000 tests in a day. However, it emerges that the government has been counting tests posted out but not actually completed.

That is despite Mr Johnson and others stating the numbers are for tests ‘carried out’.

The numbers tumble below the target again in the following days, although the government insists capacity remains in place.

May 5: Trials of an NHSX app to track who has been in proximity to infected people begin on the Isle of Wight. 

Chief scientific officer Patrick Vallance admits ramping up testing earlier would have been ‘beneficial’. 

May 18: It emerges the app will not be ready for national use by ‘mid-May’ as planned, although Downing Street insists track and trace can start without it.

Mr Hancock announces that everyone over the age of five displaying coronavirus symptoms can now apply for a test, although key workers and patients will be prioritised. 

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