A health worker applies a dose of the AstraZeneca vaccine during the first day of a three-day COVID-19 vaccination campaign for people over age 35 in the Complexo da Maré favela of Rio de Janeiro, Brazil, Brazil, Thursday, July 29, 2021. Some recipients will be monitored to study the rate of protection the vaccines provide and the extent to which virus variants are circulating. (Photo by Bruna Prado/AP Photo)

A man walks pat sculptures with face masks on along an alley in Beijing on August 3, 2021. (Photo by Noel Celis/AFP Photo)

A British RAF Typhoon aircraft escorts a C130 transport plane on its way to Jordan for an airdrop of paratroopers from the U.K.'s 16th Air Assault Brigade as part of an exercise conducted jointly with Jordanian soldiers on Wednesday, June 23, 2021. (Photo by Petros Karadjias/AP Photo)

A reconstruction of the first Neanderthal in the Netherlands, nicknamed Krijn, is on display in the National Museum of Antiquities in Leiden, The Netherlands, 06 September 2021. Krijn's face has been worked on for years by the brothers Adrie and Alfons Kennis. (Photo by Bart Maat/EPA/EFE)

Chile's Mary Dee Vargas (L) reacts after defeating Brazil's Larissa Farias compete in their Judo Women's –48 kg Bronze Medal contest during the Lima 2019 Pan-American Games in Lima on August 8, 2019. (Photo by Guadalupe Pardo/Reuters)

Men dressed in protective suits stand around the coffin of Kenyan doctor Daniel Alushula who died of coronavirus disease (COVID-19), during his funeral in the village of Khumusalaba, in Kakamega county, Kenya on November 13, 2020. (Photo by Baz Ratner/Reuters)

A flight crew from China Airlines, wearing protective masks, stand in the international terminal after arriving on a flight from Taipei at Los Angeles International Airport (LAX) on February 28, 2020 in Los Angeles, California. The World Health Organization (WHO) has raised the global coronavirus risk level to “very high”. (Photo by Mario Tama/Getty Images)

A woman shouts slogans as she marches to Congress to commemorate International Women's Day in Buenos Aires, Argentina, Monday, March 9, 2020. (Photo by Natacha Pisarenko/AP Photo)