These are the UK coronavirus stories you need to know about Sunday.
Prime Minister Boris Johnson has been admitted to hospital for tests. Downing Street issued a statement saying: "On the advice of his doctor, the Prime Minister has tonight been admitted to hospital for tests.
"This is a precautionary step, as the Prime minister continues to have persistent symptoms of coronavirus 10 days after testing positive for the virus."
Deaths of Two More Healthcare Workers Announced
There were another 621 hospital COVID-19 deaths announced today, a smaller rise than Saturday, bringing the total to 4934.
NHS England said of those who died in England, patients were aged between 33 years and 103 years old. Twenty-nine of the 555 patients (aged between 35 and 95 years old) had no known underlying health condition.
The COVID-19 deaths of two more healthcare workers were reported today.
In a statement, Lance McCarthy, chief executive, The Princess Alexandra Hospital NHS Trust, said she was "a long-standing member of our maternity team who will be remembered for her professionalism and commitment to the women she supported."
He added: "Her loss will be felt by the maternity team and colleagues from across the organisation."
Her family also issued a statement: "As a family, our hearts are broken at the loss of our loving, wonderful and caring mum, sister, daughter and grandmother."
It continued: "What we also know is how proud she was to be an NHS midwife. Lynsay followed her dream and trained as a midwife later in life. It was a role she committed herself to and saw the midwifery team at the Princess Alexandra Hospital as her other family. She was a very well-respected midwife who supported many hundreds of women as they welcomed their babies into the world."
Jacqueline Dunkley-Bent, chief midwifery officer for England, said: "Lynsay was clearly a highly regarded midwife whose dedication to women, babies and their families will be remembered and cherished by her own family and her colleagues - my deepest thoughts are with them, her children, grandchildren, parents and siblings."
Nursing assistant John Alagos, 24, worked at Watford General Hospital in Hertfordshire, and died on Friday.
The hospital's chief nurse, Tracey Carter, said: "John was very popular and will be missed greatly by his colleagues."
His mother told The Mail on Sunday her son had not been wearing the right protective clothing at work and had been doing a longer shift due to staff shortages.
The hospital said: "We have always kept our staff updated on the latest PPE guidance to make sure they have the right level of protection."
Scotland's CMO Warned by Police
Scotland's CMO, Dr Catherine Calderwood, apologised "unreservedly" for not following her own stay at home advice after being photographed visiting her family’s second home in Fife.
She was later visited by police officers and warned about her conduct.
In a statement, she said: "While there are reasons for what I did, they do not justify it and they were not legitimate reasons to be out of my home."
She continued: "I understand that I did not follow the advice that I am giving to others, and I am truly sorry for that."
Police Scotland Chief Constable, Iain Livingstone, said in a statement: "The legal instructions on not leaving your home without a reasonable excuse apply to everyone."
First Minister Nicola Sturgeon defended her CMO, saying her advice was "invaluable," and that: "All of us, including me, will make mistakes in these unprecedented times we're living in."
However, it was later announced that Dr Catherine Calderwood will no longer front Scotland's COVID-19 briefings.
Update: Dr Calderwood resigned on Sunday evening. In a statement, she said: "The First Minister and I have had a further conversation this evening and we have agreed that the justifiable focus on my behaviour risks becoming a distraction from the hugely important job that Government and the medical profession has to do in getting the country through this coronavirus pandemic. Having worked so hard on the government's response, that is the last thing I want."
She continued: "It is with a heavy heart that I resign as Chief Medical Officer."
On Saturday, we reported how patients were told not to attend Watford General's emergency department "until further notice, even in an emergency". West Hertfordshire Hospitals NHS Trust said the critical incident was due to problems with oxygen and was stood down at 2230 last night: "The issues experienced today have been resolved and a safe level of oxygen was maintained throughout the duration of the incident."
Dr Jenny Harries, deputy chief medical officer for England, told the Downing Street daily briefing: "We have a system of flagging where there are potential risks or problems before they actually become a significant problem. It is the strength of our system that we have these flags going off at regular intervals."
She continued: "There is no insufficiency of oxygen and I think the public should not be concerned that if they become ill and need a hospital admission that care is available to them."
Longleat Safari Park announced that Lord Bath of Longleat, 87, died after testing positive for COVID-19.
Health Secretary Matt Hancock addressed the issue of people breaking lockdown rules: "We've included exercise as one of the things that you can leave your home to do because exercise is good for our physical and our mental health. But please do not bend or break this rule. We can't rule out further steps.
"But I don't want anyone to think that any changes to the social distancing rules are imminent. Because the vast majority are following the rules."
The Royal College of Physicians (RCP) has released results of a survey of 2513 members over 24 hours.
Twenty-two per cent were still unable to access necessary PPE.
Only 31% are able to access COVID-19 testing for themselves if they have symptoms, and 12.5% said testing was available for household members with symptoms.
The poll showed 21.5% in London, and 18.3% in the rest of England, were taking time off from their normal work schedule. The main reason was being ill with suspected COVID-19 symptoms, followed by self-isolating because someone in their household has symptoms (18.5% London, 25% rest of England).
In a statement, RCP president, Professor Andrew Goddard, said: "These figures are a stark indication of the incredibly difficult situation facing our members working in the NHS.
"The government’s current strategy to deliver testing that would support NHS staff to return to the workforce as quickly as possible clearly isn’t working.
"The fact that only 78% of respondents could access the PPE they needed is a big concern and we must aim to get to 100% as soon as possible.
"We welcome promises made this week to increase COVID-19 testing to 100,000 a day by the end of April, but NHS and social care staff and their households need tests now and progress has been far slower than the system requires. If it wants to build confidence, the Government must publish its plan, timeline and the challenges it expects."
On Sunday, Matt Hancock said 27,000 former health care professionals had now signed up to return to the NHS frontline.
Doctors Association UK claimed that some nurses are having to hold their breath because they aren't sure they have adequate protective equipment.
The Intensive Care National Audit & Research Centre released its latest ICU audit data.
Prof Duncan Young, professor of intensive care medicine, University of Oxford, analysed the data for the Science Media Centre: "By midday on Friday it recorded 2621 admissions of patients with COVID-19 infections to ICUs in England, Wales and Northern Ireland. The majority are still being treated in an ICU.
"As in the previous report, the patients are predominantly male (73%), with an average age of 60. The largest number of cases are still in London, Thames Valley and South-east regions.
"The number of patients who have left ICU has increased quite considerably since the last report. Data are available on 690 discharges. Of these half were discharged alive and half died on the ICU. Data are available on a smaller number of discharged patients (388) who had required treatment with a ventilator (artificial ventilation). Only a third of these patients survived to leave an ICU. ICNARC supplies comparator data for non-COVID-19 viral pneumonia where the mortality of patients treated in an ICU was 22%. In general patients with the acute respiratory distress syndrome (ARDS), which causes a similar deterioration in lung function requiring artificial ventilation, have less than 20% mortality.
"The relative ineffectiveness of artificial ventilation might suggest that COVID-19 causes a particularly treatment-resistant form of pneumonitis. It is also possible that in some patients COVID-19 is causing multi-organ failure of which the respiratory failure is the presenting problem but may not always be the cause of death – but there are no data on this yet."
On Sunday, Matt Hancock said: "There are currently over 2336 spare critical care beds for the NHS in England, and over 9000 ventilators are now available to NHS coronavirus patients across the country."
On ventilators, he added: "The goal continues to be to keep ramping it up to the 18,000 target that we've set, and we don't expect … to need 18,000. But I want to keep the ramp up going because I always want to keep the supply ahead of the need."
In a rare recorded TV address broadcast tonight at 8 pm, the Queen will thank NHS frontline workers, care workers, and those carrying out essential roles. She'll say: "I hope in the years to come everyone will be able to take pride in how they responded to this challenge. And those who come after us will say that the Britons of this generation were as strong as any. That the attributes of self-discipline, of quiet good-humoured resolve and of fellow-feeling still characterise this country."
The TV crew was reported to have worn masks and gloves and kept at a safe distance for the recording.