A health worker receives a dose of the Sinopharm coronavirus vaccine at a clinic in Basra, Iraq, Wednesday, March 3, 2021. (AP Photo/Nabil al-Jurani)

A cyclist passes in front of an ambulance by an infectious diseases hospital in Warsaw, Poland, on Thursday, March 25, 2021. Amid a sharp spike in new infections and hospitalizations that are bringing the health care to its limits, Poland has stepped up pandemic measures for two weeks starting Saturday, including fewer people to be allowed into churches at the holiday time. (AP Photo/Czarek Sokolowski)

FILE - In this Dec. 2, 2020, file photo, Arizona Republican Gov. Doug Ducey arrives for a news conference to talk about the latest Arizona COVID-19 information in Phoenix. Ducey is prohibiting government mask mandates and allowing bars and nightclubs shuttered for months to open their doors without restrictions. Ducey's move Thursday, March 25, 2021, leaves in place few of the restrictions he implemented to curb the spread of the coronavirus. (AP Photo/Ross D. Franklin, Pool, File)

President Joe Biden walks at the end of his first formal news conference in the East Room of the White House, Thursday, March 25, 2021, in Washington. (AP Photo/Evan Vucci)

FILE - In this Wednesday, March 24, 2021 file photo, a vial of the AstraZeneca COVID-19 vaccination on a table prior to Croatia's Parliament Speaker Gordan Jandrokovic and Prime Minister Andrej Plenkovic being vaccinated, in Zagreb, Croatia. AstraZeneca says that its COVID-19 vaccine is strongly effective even after counting additional illnesses in its disputed U.S. study. The announcement late Wednesday was the latest in an extraordinary public rift with American officials. The drugmaker said it had recalculated data from that study and concluded the vaccine is 76% effective in preventing symptomatic COVID-19, instead of the 79% it had reported earlier in the week. (Admir Buljubasic/Pool via AP, File)

A health workers waits to conduct tests for COVID-19 at a roadside camp in Mumbai, India, Thursday, March 25, 2021. (AP Photo/Rajanish Kakade)

An egg vendor waits for customers at a deserted market in Budapest, Hungary, Thursday, March 25, 2021. Hungary, with the world's highest per capita death rate, set a record for daily deaths on Thursday with 252, bringing the death toll to nearly 19,000 in the country, which has a population of less than 10 million. (AP Photo/Laszlo Balogh)

FILE - In this March 10, 2021, file photo, California Gov. Gavin Newsom addresses the media during a visit to a vaccination center in South Gate, Calif. California is expanding its vaccine eligibility to anyone 50 and over starting in April and anyone 16 and over on April 15. Gov. Newsom said Thursday, March 25, 2021, that California expects to receive 2.5 million doses a week in the first half of April and more than 3 million a week in the second half of the month. (AP Photo/Marcio Jose Sanchez, File)

Parishioners attend a Mass relayed via loudspeaker outside Our Lady of Sorrows in the Queens borough of New York on Sunday, March 21, 2021. The Rev. Manuel Rodriguez says more than 100 parishioners of the Roman Catholic church have died from COVID-19. (AP Photo/Jessie Wardarski)

A man visits the archaeological site of Babylon, Iraq, Sunday, March 21, 2021. (AP Photo/Hadi Mizban)

Stephany Martinez wipes tears from her eyes as she talks about losing her grandparents to the coronavirus, while sitting next to her mother, Reyna Martinez, at Our Lady of Sorrows Roman Catholic church in the Queens borough of New York on Friday, March 5, 2021. Both are parishioners of the church. (AP Photo/Jessie Wardarski)

A retractable needle is seen after a person receives a vaccine at Mercedes-Benz Stadium on Thursday, March 25, 2021, in Atlanta. Gov. Brian Kemp said all Georgians 16 and older will be eligible to receive the COVID-19 vaccine. (AP Photo/Brynn Anderson)

Boxes of the Pfizer vaccine are unloaded at the Sarajevo Airport, in Bosnia, Thursday, March 25, 2021. A plane carrying 24.000 Pfizer vaccines, part of the international COVAX initiative to ensure vaccine access for low- and middle-income countries, delivered the first COVAX vaccines to Bosnia. (AP Photo/Kemal Softic)

Pakistani planes flyover during a military parade celebrating Pakistan National Day celebrations, in Islamabad, Pakistan, Thursday, March 25, 2021. The military parade in the capital showcased short and long-range missiles, tanks, jets drones and other hardware. (AP Photo/Anjum Naveed)

A man wearing a decorated face mask, poses for a photo in Budapest, Hungary, Thursday, March 25, 2021. Hungary, with the world's highest per capita death rate, set a record for daily deaths on Thursday with 252, bringing the death toll to nearly 19,000 in the country, which has a population of less than 10 million. (AP Photo/Laszlo Balogh)

FILE - In this Sunday, April, 19 2020, file picture Volunteers wearing protective outfits light candles during the Orthodox Easter service, held without any worshipers due to COVID-19 restrictions in Bucharest, Romania. As Romania battles against a surge of COVID-19 infections authorities announced on Thursday March 25, 2021, that Easter celebrations in the deeply Christian country will physically go ahead this year. (AP Photo/Vadim Ghirda, File)

British Prime Minister Boris Johnson, center, sits with children drawing of a bunch of bananas during a visit to the Monkey Puzzle Nursery in Greenford, west London, Thursday, March 25, 2021. (Jeremy Selwyn/Pool Photo via AP)

German Chancellor Angela Merkel addresses the German parliament Bundestag ahead of an European Union summit at the Reichstag building in Berlin, Germany, Thursday, March 25, 2021. (AP Photo/Markus Schreiber)

Community educator Asha Brown, left, tries to persuade Leo Baylor, standing right, to be vaccinated against COVID-19, in Chicago on Tuesday, Feb. 23, 2021. Brown, a respiratory therapist, was enlisted by Saint Anthony Hospital to promote vaccination in hard hit Black and brown neighborhoods. Baylor expressed reluctance but wanted more information. (AP Photo/Teresa Crawford)