A school girl reacts as a health worker inoculates her with the dose of Pfizer-BioNTech vaccine against the Covid-19 coronavirus for the 12-15 years age group at an educational institution in Colombo on January 7, 2022. (Photo by Ishara S. Kodikara/AFP Photo)

In this photograph taken on February 18, 2016, Pakistani children ride on swings in the predominantly Pashtun Korangi District of Karachi. In a rundown district of Karachi, Rabia balks at a neighbour's proposal to vaccinate her children, demonstrating one of the biggest hurdles to eradicating polio in Pakistan by the end of the year: confused and frightened parents. (Photo by Asif Hassan/AFP Photo)

A woman wearing a protective mask is seen behind a girl dressed in a Plague Doctor Mask in Western-Ukrainian city of Lviv, Ukraine, 22 March 2020. Ukrainian Designer Anastasia Markovska sewed protective masks looking like Plague Doctor Masks, the traditional costume of Venice Carnival, for herself and her friends due to the ongoing pandemic of the COVID-19 disease caused by the SARS-CoV-2 coronavirus. In Ukraine had been 47 laboratory-confirmed cases of COVID-19, including three deaths and one recovery as Ukraine's Health Ministry announced. (Photo by Pavlo Palamarchuk/EPA/EFE)

A Guarani boy pets a puppy in the Mata Verde Bonita village, in Marica, Rio de Janeiro state, Brazil, Thursday, February 25, 2020, where healthcare workers are making the rounds with coolers containing doses of China's Sinovac COVID-19 vaccine as part of a mass immunization program aimed at inoculating all of Rio's 16 million residents by the end of the year. (Photo by Bruna Prado/AP Photo)

A health worker shows an empty syringe after inoculating a woman with AstraZeneca's COVID-19 vaccine during the first day of a nationwide three-day vaccination drive at a school in Quezon city, Philippines on Monday, November 29, 2021. There has been no reported infection so far caused by the new variant in the Philippines, a Southeast Asian pandemic hotspot where COVID-19 cases have considerably dropped to below 1,000 each day in recent days, but the emergence of the Omicron variant has set off a new alarm. (Photo by Aaron Favila/AP Photo)

A woman wearing in face mask to curb the spread of COVID-19 passes street's cafe in Kyiv, Ukraine, Friday, October 22, 2021. Coronavirus infections and deaths in Ukraine have surged to all-time highs amid a laggard pace of vaccination, which is one of the lowest in Europe. (Photo by Efrem Lukatsky/AP Photo)

Dave Woods, 47, waits on an overpass in support for trucks driving in a convoy bound for the nation's capital to protest against coronavirus disease (COVID-19) vaccine mandates, in Wabash Township, Illinois, U.S. March 1, 2022. (Photo by Cheney Orr/Reuters)

A foreign passenger wearing a protective suit poses as they prepare for their flight at Manila's International Airport, Philippines, Monday, January 18, 2021. Coronavirus infections in the Philippines have surged past 500,000 in a new bleak milestone with the government facing criticisms for failing to immediately launch a vaccination program amid a global scramble for COVID-19 vaccines. (Photo by Aaron Favila/AP Photo)