A woman leaves a pharmacy store as a notice is seen on its door that reads "masks and effervescent tablets sold out" in Shanghai, China January 22, 2020.

Workers in protective suits check the temperature of passengers arriving at the Xianning North Station on the eve of the Chinese Lunar New Year celebrations, in Xianning, a city bordering Wuhan to the north, in Hubei province, China January 24, 2020.

A picture released by the Central Hospital of Wuhan shows medical staff attending to patient at the The Central Hospital Of Wuhan Via Weibo in Wuhan, China on an unknown date. THE CENTRAL HOSPITAL OF WUHAN VIA WEIBO/Handout via REUTERS

A visitor wearing a mask walks outside the Shanghai Disney Resort, that will be closed during the Chinese Lunar New Year holiday following the outbreak of a new coronavirus, in Shanghai, China January 24, 2020.

A security guard wears a mask at a shopping mall in the Nanjing Pedestrian Road, a main shopping area, in Shanghai, China January 24, 2020.

A man wearing a protective mask is seen on a subway in Shanghai, China January 23, 2020.

People stand in front of the closed gate of Lama Temple, with a notice saying that the temple is closed for safety concerns following the outbreak of a new coronavirus on its gate, in Beijing, China January 24, 2020.

A security guard sits at the entrance of a closed temple in Shanghai, China January 24, 2020.

Workers dismantle decorations after the temple fair for the Chinese Lunar New Year in Ditan Park was canceled in Beijing, China January 24, 2020.

A man wearing a protective mask walks at Ditan Park in Beijing, China January 24, 2020.

A worker sanitizes the square in front of the Hankou Railway Station, closed after the city of Wuhan was locked down following the outbreak of a new coronavirus, in Wuhan, Hubei province, China January 23, 2020. China Daily via REUTERS

Police officers wearing masks check the boot of a car for smuggled wild animals at an expressway toll station following the outbreak of a new coronavirus, on the eve of the Chinese Lunar New Year celebrations, outside Wuhan, Hubei province, China January 24, 2020.

Chinese paramilitary officers wearing masks stand guard at an entrance of the closed Hankou Railway Station after the city was locked down following the outbreak of a new coronavirus in Wuhan, Hubei province, China January 23, 2020. China Daily via REUTERS

Workers dismantle x-ray machines and walk-through metal detectors after the temple fair for the Chinese Lunar New Year in Ditan Park was canceled in Beijing, China January 24, 2020.

People line up outside a drugstore to buy masks in Shanghai, China January 24, 2020.

Police officers wearing masks check the boot of a car for smuggled wild animals following the outbreak of a new coronavirus, at an expressway toll station on the eve of the Chinese Lunar New Year celebrations, in Xianning, a city bordering Wuhan to the north, Hubei province, China January 24, 2020.

People wearing masks work at a hospital in Wuhan, Hubei province, China January 22, 2020, in this still image taken from video. China News Service/via REUTERS

A security officer in a protective mask checks the temperature of a passenger following the outbreak of a new coronavirus, at an expressway toll station on the eve of the Chinese Lunar New Year celebrations, in Xianning, a city bordering Wuhan to the north, Hubei province, China January 24, 2020.

A staff member from a local sanitation and epidemic prevention team checks body temperature of a passenger in a car at a toll station in Wuhan, Hubei province, China January 23, 2020. China Daily via REUTERS

Officials monitor thermal scanners at a temperature monitoring station at Portas do Cerco in Macau, China, January 8, 2020. Picture taken January 8, 2020. MACAU SAR HEALTH BUREAU/Handout via REUTERS.

A man wearing a mask is seen at the Nanjing Pedestrian Road, a main shopping area, in Shanghai, China January 24, 2020.

A man holding an umbrella walks past excavators at the construction site where the new hospital is being built to treat patients of a new coronavirus following the outbreak and the city’s lockdown, on the outskirts of Wuhan, China January 24, 2020. cnsphoto via REUTERS.