Swedish climate change activist Greta Thunberg, Isabelle Axelsson and German Luisa Neubauer take part in a climate strike protest during the 50th World Economic Forum (WEF) annual meeting in Davos, Switzerland on January 24, 2020. (Photo by Denis Balibouse/Reuters)

Wu Lingling, a nurse from Central Hospital of Shanghai Fengxian District says goodbye to her husband Zhao Kun before leaving for Wuhan at Shanghai South Railway Station in east China's Shanghai, January 27, 2020. A team comprised of 50 medical workers from 40 hospitals in Shanghai left for Wuhan City on Monday to aid the novel coronavirus control efforts there. (Photo by Ding Ting/Xinhua News AgencyAlamy Live News)

An unidentified man brandishes a gun during a protest against a new citizenship law outside the Jamia Millia Islamia University in New Delhi, India, January 30, 2020. The gunman went live on Facebook to warn he was taking his “final journey” before firing at the protest. (Photo by Danish Siddiqui/Reuters)

A model performs on the catwalk of the Lambertz Monday Night event at Alter Wartesaal in Cologne, Germany, 03 February 2020. (Photo by Friedemann Vogel/EPA/EFE)

Indian students with face painted pose for a photo during an inter-college face painting competition at the Government Sardar Vallabh Bhai Patel Polytechnic College in Bhopal, India, 17 February 2020. Over fifty people participated in the event and made face paintings on various issues including the coronavirus or COVID-19. (Photo by Sanjeev Gupta/EPA/EFE)

Costumed revelers pose in front of the Chapell bridge on the opening day of the carnival in Lucerne, Switzerland, 20 February 20​20. The carnival takes place in Lucerne from 20 to 25 February 2020. (Photo by Alexandra Wey/EPA/EFE)

People wear masks to help guard against the Coronavirus in downtown Tehran, Iran, Sunday, February 23, 2020. On Sunday Iran's health ministry raised the death toll from the new virus to 8 people in the country, amid concerns that clusters there, as well as in Italy and South Korea, could signal a serious new stage in its global spread. (Photo by Ebrahim Noroozi/AP Photo)

U.S. President Donald Trump holds news conference on the coronavirus outbreak at the White House in Washington, U.S., February 26, 2020. (Photo by Carlos Barria/Reuters)