Two families who gave permission to be photographed, maintain social distancing while talking to each other outside a home in Hampstead, north London, Sunday May 3, 2020, as the UK continues in lockdown to help curb the spread of the coronavirus. The highly contagious COVID-19 coronavirus has impacted on nations around the globe, many imposing self isolation and exercising social distancing when people move from their homes. (Victoria Jones / PA via AP)

FILE - In this April 17, 2020 file photo, a couple wearing face masks to help protect against the spread of the new coronavirus walks in the rain at the Gyeongbok Palace, the main royal palace during the Joseon Dynasty, in Seoul, South Korea. Nervous travelers, spotty air service, health risks _ the battered global tourism industry is facing unprecedented uncertainty in the wake of the new coronavirus. Millions of workers are laid off or furloughed, and it will likely take years for the industry to get back to the strong demand it was seeing just six months ago. (AP Photo/Ahn Young-joon, File)

Livia and Lorenza enjoy the sun with their daughter Sara at Islands Brygge in Copenhagen on Sunday, May 3, 2020. Marked areas on the grassland help people keep distance from each other, with about 40 m2 area marked out for a maximum of 10 people, to limit the spread of coronavirus infection, seen with 48 mm telephoto lens. (Ida Guldbaek Arentsen / Scanpix via AP)

People in a sparsely populated Hyde Park, with the Serpentine lake, in central London, as the UK continues in lockdown to help curb the spread of the coronavirus, Sunday May 3, 2020. The highly contagious COVID-19 coronavirus has impacted on nations around the globe, many imposing self isolation and exercising social distancing when people move from their homes. (Yui Mok / PA via AP)

In this photo taken on Saturday, May 2, 2020, doctors attend to a patient inside the intensive care unit for people infected with the new coronavirus, at a hospital in Moscow, Russia. A Russian epidemiologist says the sharp increase in coronavirus infection cases recorded over the past week reflects increased testing. Russia on Sunday reported more then ten thousand new cases, nearly double the new cases reported a week ago and the first time the daily tally went into five digits.(AP Photo/Sophia Sandurskaya)

Marina and Andrea enjoy the sun with their daughter Sara at Islands Brygge in Copenhagen on Sunday, May 3, 2020. Marked areas on the grassland help people keep distance from each other, with about 40 m2 area marked out for a maximum of 10 people, to limit the spread of coronavirus infection, seen with 24 mm telephoto lens. (Ida Guldbaek Arentsen / Scanpix via AP)

A cyclist watches Greylag geese walk past in a sparsely populated Hyde Park area of central London, as the UK continues in lockdown to help curb the spread of the coronavirus, Sunday May 3, 2020. Many Greylag Geese from eastern Sweden, Finland and east central Europe migrate to winter in southern Europe, some in London. The highly contagious COVID-19 coronavirus has impacted on nations around the globe, many imposing self isolation and exercising social distancing when people move from their homes. (Yui Mok / PA via AP)

A woman wearing a home made face shield and mask walks a dog in Piccadilly Circus, central London, Sunday, May 3, 2020. The highly contagious COVID-19 coronavirus has impacted on nations around the globe, many imposing self isolation and exercising social distancing when people move from their homes. (AP Photo/Matt Dunham)

A woman wearing a home made face shield and mask walks a dog near Piccadilly Circus in central London, Sunday, May 3, 2020. The highly contagious COVID-19 coronavirus has impacted on nations around the globe, many imposing self isolation and exercising social distancing when people move from their homes. (AP Photo/Matt Dunham)

A customer has his temperature taken before entering the Loon Fung Chinese supermarket on Gerrard Street in London's Chinatown district, Sunday, May 3, 2020. The highly contagious COVID-19 coronavirus has impacted on nations around the globe, many imposing self isolation and exercising social distancing when people move from their homes. (AP Photo/Matt Dunham)

Mounted police patrol on horses as people exercise on a seafront promenade in Barcelona, Spain, Sunday, May 3, 2020. Spaniards have filled the streets of the country to do exercise after seven weeks of confinement to their homes to fight the coronavirus pandemic. People ran, walked, or rode bicycles under a brilliant sunny sky in Barcelona on Saturday, where many flocked to the maritime promenade to get as close as possible to the still off-limits beach. (AP Photo/Emilio Morenatti)

A jogger stops to tie his shoelace next to a recently painted NHS (National Health Service) Superman design mural by street artist Lionel Stanhope during the coronavirus lockdown, in the Waterloo area of London, Sunday, May 3, 2020. The highly contagious COVID-19 coronavirus has impacted on nations around the globe, many imposing self isolation and exercising social distancing when people move from their homes. (AP Photo/Matt Dunham)

In this photo taken on Saturday, May 2, 2020, doctors work inside the intensive care unit for people infected with the new coronavirus, at a hospital in Moscow, Russia. A Russian epidemiologist says the sharp increase in coronavirus infection cases recorded over the past week reflects increased testing. Russia on Sunday reported more then ten thousand new cases, nearly double the new cases reported a week ago and the first time the daily tally went into five digits.(AP Photo/Sophia Sandurskaya)

In this photo taken on Saturday, May 2, 2020, a doctor looks a et a computer screens of a tomography scan machine at a hospital in Moscow, Russia, Saturday, May 2, 2020. A Russian epidemiologist says the sharp increase in coronavirus infection cases recorded over the past week reflects increased testing. Russia on Sunday reported more then ten thousand new cases, nearly double the new cases reported a week ago and the first time the daily tally went into five digits.(AP Photo/Sophia Sandurskaya)