Mr Jenrick, the Secretary of State for Housing, Communities and Local Government, delivered the press conference on Sunday, March 29, alongside deputy chief medical officer Dr Jenny Harries.
He also joined Mr Johnson and Dr Harries during a briefing the week before.
Here, we take a look at Mr Jenrick's political career so far.
Who is Robert Jenrick?
Born in Wolverhampton, Mr Jenrick, 38, grew up in Shropshire and Herefordshire.
He went to Wolverhampton Grammar School before going to study history at St John's College, Cambridge.
While he was there, he was news editor of the student newspaper Varsity in 2001, before graduating in 2003.
He went on to study at the University of Pennsylvania in the US, before gaining a graduate diploma in law from The College of Law in the UK in 2005 and completing a legal practice course at BPP Law School in 2006.
He qualified as a solicitor in 2008, before pursuing a career in business a few years later.
Before he was elected to Parliament to represent Newark in 2014, he was a director at London art auction house Christie's.
Political career highlights
Mr Jenrick first ran for election for the Conservatives in 2010 in Newcastle-Under-Lyme, but lost out to the Labour candidate by 1,582 votes.
He was elected to the Conservative seat of Newark in 2013 after the resignation of Patrick Mercer.
At a by-election in 2014, he retained the seat with a majority of 7,403 - the strongest peacetime by-election result for the Conservative Party in Government for more than 40 years.
Mr Jenrick was elected to the House of Commons Health Committee shortly after winning his seat in 2014.
In 2015, he was appointed Parliamentary Private Secretary (PPS) to employment minister Esther McVey.
He was re-elected in the 2015 general election with 57 per cent of the vote.
He was then appointed PPS to Michael Gove and then his successor Liz Truss in 2016.
Mr Jenrick was against the UK leaving the EU during the 2016 referendum, according to the Spectator.
In 2018, he was appointed Exchequer Secretary to the Treasury by then Prime Minister Theresa May, becoming the youngest minister in the Government.
Then, in July 2019, Mr Jenrick was appointed Housing Secretary by Mr Johnson, becoming the youngest member of the Cabinet.
What has he announced in relation to coronavirus?
On Sunday, March 29, Mr Jenrick announced that all parts of the UK have been put on "emergency footing", which he said was "unprecedented in peacetime".
"We haven’t done anything like this since the Second World War," he said. "This means that we’re establishing strategic co-ordination centres across the whole country."
The co-ordination centres will involve senior members of the all the emergency services and also the armed forces.
He also said 50,000 emergency packages including cereal, fruit, tinned goods, teabags, biscuits, toiletries and other essentials will have been sent out to vulnerable people in self-isolation by the end of this week.
The Government has delivered 170 million masks, 42.8 million pairs of gloves, 32 million aprons, 182,000 gowns and 2.3 million pairs of eye protectors to 58,000 NHS trusts and centres, he added.