Government workers wearing personal protective equipment on a street in the locked-down part of the Jordon district on January 24, 2021 in Hong Kong, China. Hong Kong government locked-down tens of thousand of residents to contain a worsening outbreak of the coronavirus. Residents tested negative for Covid-19 can now leave and re-enter the area and the restriction is expected to lift by midnight. (Photo by Anthony Kwan/Getty Images)





A worker wearing a face mask and face shield to help curb the spread of the coronavirus uses a loud speaker to ask a masked passenger to keep distancing in the line at the South Train Station in Beijing, Thursday, January 28, 2021. Efforts to dissuade Chinese from traveling for Lunar New Year appeared to be working. Beijing's main train station was largely quiet on the first day of the travel rush and estimates of passenger totals were smaller than in past years. (Photo by Andy Wong/AP Photo)





Travelers wearing face masks to protect against the spread of the coronavirus walk with their luggage at the Beijing Railway Station in Beijing, Thursday, January 28, 2021. (Photo by Mark Schiefelbein/AP Photo)





Workers wearing face masks and face shields to help curb the spread of the coronavirus assist masked passengers to board their trains at the South Train Station in Beijing, Thursday, January 28, 2021. (Photo by Andy Wong/AP Photo)





A traveller wearing protective gear to help curb the spread of the coronavirus sits alone on the bench as he waits for his train at the South Train Station in Beijing, Thursday, January 28, 2021. (Photo by Andy Wong/AP Photo)





A traveler wearing a face mask to protect against the spread of the coronavirus carries his luggage as he walks out of an exit at the Beijing Railway Station in Beijing, Thursday, January 28, 2021. (Photo by Mark Schiefelbein/AP Photo)





A woman wearing a face mask and face shield to help curb the spread of the coronavirus prepares to board her train at the South Train Station in Beijing, Thursday, January 28, 2021. (Photo by Andy Wong/AP Photo)





Travelers are screened before entering the Wuchang train station at the start of the annual Lunar New Year travel in Wuhan in central China's Hubei province on Thursday, January 28, 2021. Efforts to dissuade Chinese from traveling for Lunar New Year appeared to be working as Beijing’s main train station was largely quiet and estimates of passenger totals were smaller than in past years. (Photo by Ng Han Guan/AP Photo)





This aerial photo shows bullet trains parked at a station in preparation for the upcoming Lunar New Year travel peak in Nanjing, in eastern China's Jiangsu province on January 27, 2021, as authorities have encouraged people to stay put during the Spring Festival to curb the spread of of COVID-19 coronavirus. (Photo by AFP Photo/China Stringer Network)





A security officer wearing a mask and a cap with the Chinese national flag guards the entrance after the World Health Organization team arrive at an exhibition about the fight against the coronavirus in Wuhan in central China's Hubei province on Saturday, January 30, 2021. The World Health Organization team investigating the origins of the coronavirus pandemic visited another Wuhan hospital that had treated early COVID-19 patients on their second full day of work on Saturday. (Photo by Ng Han Guan/AP Photo)





Customers wearing face mask shop for decorations, ahead of the Chinese Lunar New Year, following the coronavirus disease (COVID-19) outbreak, in Hong Kong, China on January 28, 2021. (Photo by Tyrone Siu/Reuters)





Security guards wearing face masks carry a giant balloon in the shape of a fish ahead of the Chinese Lunar New Year festivity at Yu Garden, following the coronavirus disease (COVID-19) outbreak in Shanghai, China on January 29, 2021. (Photo by Aly Song/Reuters)





Qiaonan village makes use of the advantages of broad tidal flat and rich water resources to develop goose and duck industry, so as to increase the villagers' income in Sanhe Town, Hongze District, Huai 'an City, east China's Jiangsu Province, 25 January 2021. (Photo by Rex Features/Shutterstock)





Residents wearing masks to help curb the spread of the coronavirus queue up at a popular food stall in Wuhan, China, Tuesday, January 26, 2021. The central Chinese city of Wuhan, where the coronavirus was first detected, has largely returned to normal but is on heightened alert against a resurgence as China battles outbreaks elsewhere in the country. (Photo by Ng Han Guan/AP Photo)





Security personnel block journalists after the World Health Organization team arrive at the Baishazhou wholesale market on the third day of field visit in Wuhan in central China's Hubei province on Sunday, January 31, 2021. WHO says the team plans to visit hospitals, markets and laboratories in a politically charged mission as China seeks to avoid blame for alleged early missteps. A single visit by scientists is unlikely to confirm the virus’s origins. (Photo by Ng Han Guan/AP Photo)





A worker wearing a face mask carries red lanterns, ahead of the Chinese Lunar New Year, following the coronavirus disease (COVID-19) outbreak, in Hong Kong, China on January 28, 2021. (Photo by Tyrone Siu/Reuters)





A resident wearing a mask sits outside the clinic entrance of the Hubei Provincial Hospital of Integrated Chinese and Western Medicine also known as the Hubei Province Xinhua Hospital where a World Health Organization team of researchers arrive on its first field trip in Wuhan in central China's Hubei province on Friday, January 29, 2021. The World Health Organization team of researchers emerged from their hotel Thursday for the first time since their arrival in the central Chinese city of Wuhan to start searching for clues into the origins of the COVID-19 pandemic. (Photo by Ng Han Guan/AP Photo)





A security camera is seen on an advertising billboard in Hong Kong on January 26, 2021. (Photo by Peter Parks/AFP Photo)





A man wearing a face mask to help curb the spread of the coronavirus browses his smartphone while stretching his leg at a public park in Beijing, Tuesday, January 26, 2021. Countries must cooperate more closely in fighting the challenges of the pandemic and climate change and in supporting a sustainable global economic recovery, Chinese President Xi Jinping said on Monday in an address to the World Economic Forum. (Photo by Andy Wong/AP Photo)