A child wearing a face mask to help curb the spread of the coronavirus holds a dinosaur shaped balloon walks at a public park in Beijing, Sunday, May 16, 2021. (AP Photo/Andy Wong)

Linda Zeigler, of nurse with St. Clair Health, administers the Pfizer COVID-19 vaccine to Jameson Cooley, 12, of Shadyside in Pittsburgh, Pa., at a clinic organized by St. Clair Health and the Carnegie Boys and Girls Club to vaccinate youth ages 12 and older, Saturday, May 15, 2021, in Carnegie, Pa. (Alexandra Wimley/Pittsburgh Post-Gazette via AP)

Myat Myat, of Pittsburgh, Pa. second from right, receives a second dose of the COVID-19 vaccine, as her children Theinlar Soesan, 11, Lawon Kyai, 3, and Naylen Yeng, 8, look on, at a clinic organized by Age-Friendly Greater Pittsburgh, Free the Vaccine and Lively Pittsburgh to serve the Bhutanese community, Saturday, May 15, 2021, at Whitehall Presbyterian Church in Whitehall, Pa. The clinic featured a pop-up experience including Bhutanese music, samosas and chai, and a Polaroid photo opportunity to encourage people to get vaccinated. (Alexandra Wimley/Pittsburgh Post-Gazette via AP)

A woman enjoys the sun at Plaka beach on the Aegean island of Naxos, Greece, Friday, May 14, 2021. Greece launched its tourism season Friday amid a competitive scramble across the Mediterranean to lure vacationers emerging from lockdowns. (AP Photo/Thanassis Stavrakis)

Britain's Prime Minister Boris Johnson speaking at a press conference about the ongoing coronavirus outbreak, in London, Friday, May 14, 2021. (AP Photo/Matt Dunham, Pool)

The employee of a pub rolls a stack of chairs onto the market place in Heidelberg, Germany, Saturday, May 15, 2021. After months of lockdown, the Southwest is loosening the reins on Corona rules significantly. From Saturday on, openings in gastronomy, tourism and leisure are possible. (Uwe Anspach/dpa via AP)

A man receives the second shot of the AstraZeneca COVID-19 vaccine from a health worker at a vaccination center in Lahore, Pakistan, Sunday, May 16, 2021. (AP Photo/K.M. Chuadary)

Several bodies are seen buried in shallow graves on the banks of Ganges river in Prayagraj, India. Saturday, May 15, 2021. Police are reaching out to villagers in northern India to investigate the recovery of bodies buried in shallow sand graves or washing up on the Ganges River banks, prompting speculation on social media that they were the remains of COVID-19 victims. (AP Photo/Rajesh Kumar Singh)

A child eats from a pot as she eyes the camera in the Penha Brasil favela where families have started relocating during the coronavirus pandemic in Sao Paulo, Brazil, Saturday, May 15, 2021. Over 200 families live in the Penha Brasil community, one of the new slums that are sprouting up around Brazil's largest city, inhabited mostly by newly unemployed workers who lost their jobs and homes as a result of the pandemic. (AP Photo/Andre Penner)

Britain's Home Secretary Priti Patel receives her first dose of the Moderna Covid-19 vaccine from Dr. Vin Diwakar at Guys Hospital in London, Saturday May 15, 2021. (Stefan Rousseu/PA via AP)

FILE - IN this Dec. 21, 2020 file photo, A family walks past Cinderella Castle in the Magic Kingdom, at Walt Disney World in Lake Buena Vista, Fla. Florida's major theme parks are adjusting their face mask policies after the federal government loosened its recommendations as more people get vaccinated for the coronavirus. Visitors to Walt Disney World and Universal Studios-Orlando were allowed Saturday, May 15, 2021 to remove their masks when they are outdoors except when they are on attractions, in line or riding a tram or other transportation.(Joe Burbank/Orlando Sentinel via AP, File)

People wait for their turn to receive the second shot of the AstraZeneca COVID-19 vaccine at a vaccination center in Lahore, Pakistan, Sunday, May 16, 2021. (AP Photo/K.M. Chuadary)

Linda Zeigler, of nurse with St. Clair Health, administers the Pfizer COVID-19 vaccine to Anita Murphy, 12, of Brookline, at a clinic organized by St. Clair Health and the Carnegie Boys and Girls Club to vaccinate youth ages 12 and older, Saturday, May 15, 2021, in Carnegie, Pa. (Alexandra Wimley/Pittsburgh Post-Gazette via AP)

Bodies of suspected Covid-19 victims are seen in shallow graves buried in the sand near a cremation ground on the banks of Ganges River in Prayagraj, India, Saturday, May 15, 2021. (AP Photo/Rajesh Kumar Singh)

Empty vials of the Pfizer-BioNTech, Moderna and AstraZeneca COVID-19 vaccine lie in a box during a vaccine campaign at the Vaccine Village in Ebersberg near Munich, Germany, Saturday, May 15, 2021. (AP Photo/Matthias Schrader)

Policemen stand next to the bodies buried in shallow graves on the banks of Ganges river in Prayagraj, India, Saturday, May 15, 2021. Police are reaching out to villagers in northern India to investigate the recovery of bodies buried in shallow sand graves or washing up on the Ganges River banks, prompting speculation on social media that they were the remains of COVID-19 victims. (AP Photo/Rajesh Kumar Singh)