Protesters holding a banner and flags demonstrate against the government measures to curb the spread of the coronavirus disease (COVID-19), in Berlin, Germany, May 1, 2021. The banner reads, "no to capital. resistance globally. left against corona arbitrariness". REUTERS/Christian Mang

Oleg Verniaiev, a gymnast of the Ukrainian Olympic team that will compete in the Tokyo 2020 Olympics, gives a thumbs-up as he receives a dose of the Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 30, 2021. REUTERS/Valentyn Ogirenko

Maryna Bekh-Romanchuk, a long jumper of the Ukrainian Olympic team that will compete in the Tokyo 2020 Olympics, receives a dose of the Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 30, 2021. REUTERS/Valentyn Ogirenko

Oleg Verniaiev, a gymnast of the Ukrainian Olympic team that will compete in the Tokyo 2020 Olympics, waits before receiving a dose of the Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 30, 2021. REUTERS/Valentyn Ogirenko

Daria Bilodid, a judoka of the Ukrainian Olympic team that will compete in the Tokyo 2020 Olympics, poses for a picture after receiving a dose of Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 30, 2021. REUTERS/Valentyn Ogirenko

Ihor Radivilov, a gymnast of the Ukrainian Olympic team that will compete in the Tokyo 2020 Olympics, poses for a picture after receiving a dose of the Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 30, 2021. REUTERS/Valentyn Ogirenko

Ihor Radivilov, a gymnast of the Ukrainian Olympic team that will compete in the Tokyo 2020 Olympics, receives a dose of Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 30, 2021. REUTERS/Valentyn Ogirenko

A nurse prepares a dose of the Sinovac's CoronaVac COVID-19 vaccine at a drive-in vaccination center, as the spread of the coronavirus disease (COVID-19) continues, in Antiguo Cuscatlan, El Salvador, April 29, 2021. REUTERS/Jose Cabezas

A man gets a dose of the Sinovac's CoronaVac COVID-19 vaccine at a drive-in vaccination center, as the spread of the coronavirus disease (COVID-19) continues, in Antiguo Cuscatlan, El Salvador, April 29, 2021. REUTERS/Jose Cabezas

A man reacts as he gets a dose of Sinovac's CoronaVac COVID-19 vaccine at a drive-in vaccination center, as the spread of the coronavirus disease (COVID-19) continues, in Antiguo Cuscatlan, El Salvador, April 29, 2021. REUTERS/Jose Cabezas

A woman gets a dose of the Sinovac's CoronaVac COVID-19 vaccine at a drive-in vaccination center, as the spread of the coronavirus disease (COVID-19) continues, in Antiguo Cuscatlan, El Salvador, April 29, 2021. REUTERS/Jose Cabezas

People arrive to get a dose of Sinovac's CoronaVac COVID-19 vaccine at a drive-in vaccination center, as the spread of the coronavirus disease (COVID-19) continues, in Antiguo Cuscatlan, El Salvador, April 29, 2021. REUTERS/Jose Cabezas

A man gets a dose of the Sinovac's CoronaVac COVID-19 vaccine at a drive-in vaccination center, as the spread of the coronavirus disease (COVID-19) continues, in Antiguo Cuscatlan, El Salvador, April 29, 2021. REUTERS/Jose Cabezas

A nurse prepares to administrate a dose of the Sinovac's CoronaVac COVID-19 vaccine at a drive-in vaccination center, as the spread of the coronavirus disease (COVID-19) continues, in Antiguo Cuscatlan, El Salvador, April 29, 2021. REUTERS/Jose Cabezas

A man get a dose of the Sinovac's CoronaVac COVID-19 vaccine at a drive-in vaccination center, as the spread of the coronavirus disease (COVID-19) continues, in Antiguo Cuscatlan, El Salvador, April 29, 2021. REUTERS/Jose Cabezas

A woman gets a dose of the Sinovac's CoronaVac COVID-19 vaccine at a drive-in vaccination center, as the spread of the coronavirus disease (COVID-19) continues, in Antiguo Cuscatlan, El Salvador, April 29, 2021. REUTERS/Jose Cabezas

A citizen receives the second dose of Sinovac's CoronaVac coronavirus disease (COVID-19) vaccine during a vaccination day in Rio de Janeiro, Brazil April 26, 2021. REUTERS/Ricardo Moraes

A citizen receives the second dose of Sinovac's CoronaVac coronavirus disease (COVID-19) vaccine during a vaccination day in Rio de Janeiro, Brazil April 26, 2021. REUTERS/Ricardo Moraes

Donations for people with vulnerability to food insecurity are pictured as citizens wait to receive a dose of AstraZeneca's coronavirus disease (COVID-19) vaccine or second dose of Sinovac's CoronaVac during a vaccination day in Rio de Janeiro, Brazil April 26, 2021. REUTERS/Ricardo Moraes

Donations for people with vulnerability to food insecurity are pictured as citizens wait to receive a dose of AstraZeneca's coronavirus disease (COVID-19) vaccine or second dose of Sinovac's CoronaVac during a vaccination day in Rio de Janeiro, Brazil April 26, 2021. REUTERS/Ricardo Moraes

Nailda Felipe dos Santos, 65, receives the Sinovac CoronaVac coronavirus disease (COVID-19) vaccine at home, as healthcare workers administer the vaccine to elderlies who cannot leave home, in the Rocinha slum in Rio de Janeiro, Brazil April 16, 2021. REUTERS/Pilar Olivares

Raimunda Pereira de Sousa, 65, reacts after receiving the Sinovac CoronaVac coronavirus disease (COVID-19) vaccine at home, as healthcare workers administer the vaccine to elderlies who cannot leave home, in the Rocinha slum in Rio de Janeiro, Brazil April 16, 2021. REUTERS/Pilar Olivares

A medical worker shows a syringe with the Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) at a clinic in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

A medical worker fills a syringe with the Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) at a clinic in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

A medical worker fills a syringe with the Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) at a clinic in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

A medical worker shows a vial with the Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) at a clinic in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

A medical worker shows a vial with the Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) at a clinic in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

A medical worker fills a syringe with the Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) at a clinic in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

A medical worker holds a vial with the Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) before filling a syringe at a clinic in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

A medical worker shows a vial with the Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) at a clinic in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

Ukrainian Health Minister Maksym Stepanov speaks with Anna Ilina, a member of the Ukrainian Olympic shooting team that will compete in the Tokyo 2020 Olympics, as she waits before receiving a dose of Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

Oksana Kovalchuk and Daria Tykhova, members of the Ukrainian Olympic shooting team that will compete in the Tokyo 2020 Olympics, receive the Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

Oleh Tsarkov, a member of the Ukrainian Olympic shooting team that will compete in the Tokyo 2020 Olympics, receives a dose of Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

Oleh Omelchuk, a member of the Ukrainian Olympic shooting team that will compete in the Tokyo 2020 Olympics, receives a dose of Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

Ukrainian Health Minister Maksym Stepanov speaks with Anna Ilina, a member of the Ukrainian Olympic shooting team that will compete in the Tokyo 2020 Olympics, as she receives a dose of Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

Oleh Omelchuk, a member of the Ukrainian Olympic shooting team that will compete in the Tokyo 2020 Olympics, waits before receiving a dose of Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

Oleksandr Petriv, a member of the Ukrainian Olympic shooting team that will compete in the Tokyo 2020 Olympics, waits before receiving a dose of Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

Serhiy Kulish, a member of the Ukrainian Olympic shooting team that will compete in the Tokyo 2020 Olympics, receives a dose of Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

Oleksandr Petriv, a member of the Ukrainian Olympic shooting team that will compete in the Tokyo 2020 Olympics, receives a dose of Chinese-developed CoronaVac vaccine against the coronavirus disease (COVID-19) in Kyiv, Ukraine April 15, 2021. REUTERS/Valentyn Ogirenko

A health worker applies a dose of the Sinovac's CoronaVac coronavirus disease (COVID-19) vaccine in a vaccination center in San Salvador, El Salvador, April 13, 2021. REUTERS/Jose Cabezas

A woman is moved to an observation area after receiving a dose of the Sinovac's CoronaVac coronavirus disease (COVID-19) vaccine in a vaccination center in San Salvador, El Salvador, April 13, 2021. REUTERS/Jose Cabezas

People wait in an observation area after receiving a dose of the Sinovac's CoronaVac coronavirus disease (COVID-19) vaccine in a vaccination center in San Salvador, El Salvador, April 13, 2021. REUTERS/Jose Cabezas

A health worker prepares a dose of the Sinovac's CoronaVac coronavirus disease (COVID-19) vaccine in San Salvador, El Salvador, April 13, 2021. REUTERS/Jose Cabezas

Soccer Football - Champions League - Quarter Final Second Leg - Chelsea v Porto - Ramon Sanchez Pizjuan, Seville, Spain - April 13, 2021 Chelsea's Jorginho in action with FC Porto's Jesus Corona REUTERS/Marcelo Del Pozo

Soccer Football - Champions League - Quarter Final Second Leg - Chelsea v Porto - Ramon Sanchez Pizjuan, Seville, Spain - April 13, 2021 FC Porto's Jesus Corona in action with Chelsea's Ben Chilwell and N'Golo Kante REUTERS/Marcelo Del Pozo

Soccer Football - Champions League - Quarter Final Second Leg - Chelsea v Porto - Ramon Sanchez Pizjuan, Seville, Spain - April 13, 2021 FC Porto's Jesus Corona reacts REUTERS/Marcelo Del Pozo

Soccer Football - Champions League - Quarter Final Second Leg - Chelsea v Porto - Ramon Sanchez Pizjuan, Seville, Spain - April 13, 2021 FC Porto's Jesus Corona in action with Chelsea's Ben Chilwell REUTERS/Marcelo Del Pozo

Soccer Football - Champions League - Quarter Final Second Leg - Chelsea v Porto - Ramon Sanchez Pizjuan, Seville, Spain - April 13, 2021 FC Porto's Jesus Corona in action REUTERS/Marcelo Del Pozo

Soccer Football - Champions League - Quarter Final Second Leg - Chelsea v Porto - Ramon Sanchez Pizjuan, Seville, Spain - April 13, 2021 FC Porto's Jesus Corona in action with Chelsea's Ben Chilwell REUTERS/Marcelo Del Pozo

Soccer Football - Champions League - Quarter Final Second Leg - Chelsea v Porto - Ramon Sanchez Pizjuan, Seville, Spain - April 13, 2021 FC Porto's Jesus Corona in action with Chelsea's Jorginho, Mason Mount and Ben Chilwell REUTERS/Marcelo Del Pozo

A medical worker holds a box containing vials of the EpiVacCorona vaccine against the coronavirus disease (COVID-19), developed by the Vector Institute in Siberia, at a local clinic in Saint Petersburg, Russia April 12, 2021. REUTERS/Anton Vaganov

A medical worker fills a syringe with a dose of the EpiVacCorona vaccine against the coronavirus disease (COVID-19), developed by the Vector Institute in Siberia, at a local clinic in Saint Petersburg, Russia April 12, 2021. REUTERS/Anton Vaganov

A man receives a dose of the EpiVacCorona vaccine against the coronavirus disease (COVID-19), developed by the Vector Institute in Siberia, at a local clinic in Saint Petersburg, Russia April 12, 2021. REUTERS/Anton Vaganov

A medical specialist holds a vial of the EpiVacCorona vaccine against the coronavirus disease (COVID-19), developed by the Vector Institute in Siberia, at a local clinic in Saint Petersburg, Russia April 12, 2021. REUTERS/Anton Vaganov

A medical specialist holds a vial of the EpiVacCorona vaccine against the coronavirus disease (COVID-19), developed by the Vector Institute in Siberia, at a local clinic in Saint Petersburg, Russia April 12, 2021. REUTERS/Anton Vaganov

A medical worker holds a box containing vials of the EpiVacCorona vaccine against the coronavirus disease (COVID-19), developed by the Vector Institute in Siberia, at a local clinic in Saint Petersburg, Russia April 12, 2021. REUTERS/Anton Vaganov

A medical worker fills a syringe with a dose of the EpiVacCorona vaccine against the coronavirus disease (COVID-19), developed by the Vector Institute in Siberia, at a local clinic in Saint Petersburg, Russia April 12, 2021. REUTERS/Anton Vaganov

A woman receives a dose of the EpiVacCorona vaccine against the coronavirus disease (COVID-19), developed by the Vector Institute in Siberia, at a local clinic in Saint Petersburg, Russia April 12, 2021. REUTERS/Anton Vaganov

A woman receives a dose of the EpiVacCorona vaccine against the coronavirus disease (COVID-19), developed by the Vector Institute in Siberia, at a local clinic in Saint Petersburg, Russia April 12, 2021. REUTERS/Anton Vaganov

A medical specialist holds a vial of the EpiVacCorona vaccine against the coronavirus disease (COVID-19), developed by the Vector Institute in Siberia, at a local clinic in Saint Petersburg, Russia April 12, 2021. REUTERS/Anton Vaganov