The skyline is photographed during sunset as the spread of the coronavirus disease (COVID-19) continues in Frankfurt, Germany, April 18, 2021. REUTERS/Kai Pfaffenbach

A man wearing a protective mask walks past the European Central Bank (ECB) during sunset as the spread of the coronavirus disease (COVID-19) continues in Frankfurt, Germany, April 18, 2021. REUTERS/Kai Pfaffenbach

Locks are seen on a bridge as the spread of the coronavirus disease (COVID-19) continues in Frankfurt, Germany, April 18, 2021. REUTERS/Kai Pfaffenbach

The skyline is photographed during sunset as the spread of the coronavirus disease (COVID-19) continues in Frankfurt, Germany, April 18, 2021. Picture taken with zoom effect during long time exposure. REUTERS/Kai Pfaffenbach

A woman wearing a protective mask walks past the European Central Bank (ECB) during sunset as the spread of the coronavirus disease (COVID-19) continues in Frankfurt, Germany, April 18, 2021. REUTERS/Kai Pfaffenbach

A woman talks on her mobile phone by a cement play structure at Vincent Lugo park during the outbreak of the coronavirus disease (COVID-19), in San Gabriel, California, U.S., April 16, 2021. Picture taken April 16, 2021. REUTERS/Mario Anzuoni

A boy rests on a cement play structure shaped like a whale at Vincent Lugo park during the outbreak of the coronavirus disease (COVID-19), in San Gabriel, California, U.S., April 16, 2021. Picture taken April 16, 2021. REUTERS/Mario Anzuoni

A girl slides down on a cement play structure at Vincent Lugo park during the outbreak of the coronavirus disease (COVID-19), in San Gabriel, California, U.S., April 16, 2021. Picture taken April 16, 2021. REUTERS/Mario Anzuoni

A group of people play a drinking game in Hyde Park, as coronavirus disease (COVID-19) lockdown restrictions ease in London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People walk through Hyde Park, as coronavirus disease (COVID-19) lockdown restrictions ease in London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People play volleyball in Hyde Park, as coronavirus disease (COVID-19) lockdown restrictions ease in London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People play volleyball in Hyde Park, as coronavirus disease (COVID-19) lockdown restrictions ease in London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People gather in Hyde Park, as coronavirus disease (COVID-19) lockdown restrictions ease in London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People queue at an ice cream truck in Hyde Park, as coronavirus disease (COVID-19) lockdown restrictions ease in London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People walk through Hyde Park, as coronavirus disease (COVID-19) lockdown restrictions ease in London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People gather in Hyde Park, as coronavirus disease (COVID-19) lockdown restrictions ease in London, Britain, April 18, 2021. REUTERS/Henry Nicholls

A group of people ride a boat along Regent's Canal, as coronavirus disease (COVID-19) lockdown restrictions ease in Little Venice, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

A group of people ride a boat along Regent's Canal, as coronavirus disease (COVID-19) lockdown restrictions ease in Little Venice, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

A group of people ride a boat along Regent's Canal, as coronavirus disease (COVID-19) lockdown restrictions ease in Little Venice, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

A group of people ride a boat along Regent's Canal, as coronavirus disease (COVID-19) lockdown restrictions ease in Little Venice, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

A group of people ride a boat along Regent's Canal, as coronavirus disease (COVID-19) lockdown restrictions ease in Little Venice, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

A group of people ride a boat along Regent's Canal, as coronavirus disease (COVID-19) lockdown restrictions ease in Little Venice, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People paddle board along Regent's Canal, as coronavirus disease (COVID-19) lockdown restrictions ease in Little Venice, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People paddle board along Regent's Canal, as coronavirus disease (COVID-19) lockdown restrictions ease in Little Venice, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People sit outside a waterside cafe, as coronavirus disease (COVID-19) lockdown restrictions ease in Little Venice, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

German Chancellor Angela Merkel and a relative of a victim of COVID-19 pandemic attend a memorial ceremony in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

German President Frank-Walter Steinmeier delivers a speech during a memorial ceremony for the victims of coronavirus disease (COVID-19) pandemic, in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

German Chancellor Angela Merkel and relatives of victims of COVID-19 pandemic attend a memorial ceremony in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

German Chancellor Angela Merkel and a relative of a victim of COVID-19 pandemic attend a memorial ceremony in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

German Parliament President Wolfgang Schaeuble, President of the German Bundesrat, Reiner Haseloff and relatives of victims of COVID-19 pandemic attend a memorial ceremony, in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

A child peers from their makeshift shelter as members of Somali First Aid Association (SOFA) arrive to spray disinfectants in an effort to stop the spread of the coronavirus disease (COVID-19) at a camp for the internally displaced people in Mogadishu, Somalia April 18, 2021. REUTERS/Feisal Omar

Members of Somali First Aid Association (SOFA) arrive to spray disinfectants in an effort to stop the spread of the coronavirus disease (COVID-19) at a camp for the internally displaced people in Mogadishu, Somalia April 18, 2021. REUTERS/Feisal Omar

Members of Somali First Aid Association (SOFA) spray disinfectants in an effort to stop the spread of the coronavirus disease (COVID-19) at a camp for the internally displaced people in Mogadishu, Somalia April 18, 2021. REUTERS/Feisal Omar

Members of Somali First Aid Association (SOFA) spray disinfectants in an effort to stop the spread of the coronavirus disease (COVID-19) at a camp for the internally displaced people in Mogadishu, Somalia April 18, 2021. REUTERS/Feisal Omar

The daughter of a victim of COVID-19 pandemic attends a memorial ceremony, in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

Singers of a choir are seen on a video screen as German President Frank-Walter Steinmeier and German Chancellor Angela Merkel attend a memorial ceremony for the victims of coronavirus disease (COVID-19) pandemic, in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

German President Frank-Walter Steinmeier, German Chancellor Angela Merkel and relatives of victims attend a memorial ceremony for the victims of coronavirus disease (COVID-19) pandemic, in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

German Chancellor Angela Merkel holds a candle during a memorial ceremony for the victims of coronavirus disease (COVID-19) pandemic, in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

The wife of a victim of the COVID-19 pandemic delivers a speech during a memorial ceremony for the victims of coronavirus disease (COVID-19) pandemic, in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

German Chancellor Angela Merkel holds a candle during a memorial ceremony for the victims of coronavirus disease (COVID-19) pandemic, in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

A singer of a choir is seen on a video screen during a memorial ceremony for the victims of coronavirus disease (COVID-19) pandemic, in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

German President Frank-Walter Steinmeier delivers a speech during a memorial ceremony for the victims of coronavirus disease (COVID-19) pandemic, in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

German President Frank-Walter Steinmeier stands next to a candle during a memorial ceremony for the victims of coronavirus disease (COVID-19) pandemic, in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

German President Frank-Walter Steinmeier speaks during a memorial ceremony for the victims of coronavirus disease (COVID-19) pandemic, in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

People walk along bank of the River Thames, as coronavirus disease (COVID-19) lockdown restrictions ease in Richmond, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People relax on bank of the River Thames, as coronavirus disease (COVID-19) lockdown restrictions ease in Richmond, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People relax on bank of the River Thames, as coronavirus disease (COVID-19) lockdown restrictions ease in Richmond, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People walk along bank of the River Thames, as coronavirus disease (COVID-19) lockdown restrictions ease in Richmond, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People row a boat on the River Thames, as coronavirus disease (COVID-19) lockdown restrictions ease in Richmond, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

A band plays music on the bank of the River Thames, as coronavirus disease (COVID-19) lockdown restrictions ease in Richmond, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People row a boat on the River Thames, as coronavirus disease (COVID-19) lockdown restrictions ease in Richmond, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

A musician plays music as people walk along bank of the River Thames, as coronavirus disease (COVID-19) lockdown restrictions ease in Richmond, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People walk along bank of the River Thames, as coronavirus disease (COVID-19) lockdown restrictions ease in Richmond, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

People row a boat along the River Thames, as coronavirus disease (COVID-19) lockdown restrictions ease in Richmond, London, Britain, April 18, 2021. REUTERS/Henry Nicholls

The Standard of the German President Frank-Walter Steinmeier (L) and other German state leaders are pictured at Gendarmenmarkt square ahead of a memorial ceremony for the victims of coronavirus disease (COVID-19) pandemic, in Berlin, Germany April 18, 2021. REUTERS/Christian Mang

German Chancellor Angela Merkel arrives at a memorial event for people that died from COVID-19 at the Konzerthaus concert hall in Berlin, Germany April 18, 2021. Michael Sohn/Pool via REUTERS

Jordanian Imam Eyyas Hajibi reads the Quran inside a closed mosque, amid the coronavirus disease (COVID-19) outbreak, in Amman, Jordan April 17, 2021. Picture taken April 17, 2021. REUTERS/Muath Freij

A view shows the exterior al-Husseini mosque, as mosques are closed during Friday prayers in an attempt to curb the spread of the coronavirus disease (COVID-19), in Amman, Jordan April 16, 2021. Picture taken April 16, 2021. REUTERS/Muath Freij

A view shows al-Husseini mosque, as mosques are closed during Friday prayers in an attempt to curb the spread of the coronavirus disease (COVID-19), in Amman, Jordan April 16, 2021. Picture taken April 16, 2021. REUTERS/Muath Freij

A view shows the exterior of King Abdullah Mosque as mosques are closed during Friday prayers in an attempt to curb the spread of the coronavirus disease (COVID-19), in Amman, Jordan April 16, 2021. Picture taken April 16, 2021. REUTERS/Muath Freij