A local wears a plastic water bottle with a cutout to cover her face, as she walks on a footbridge in Hong Kong on January 31, 2020, as a preventative measure following a virus outbreak which began in the Chinese city of Wuhan. The World Health Organization, which initially downplayed the severity of a disease that has now killed 170 nationwide, warned all governments to be “on alert” as it weighed whether to declare a global health emergency. (Photo by Anthony Wallace/AFP Photo)

A mother reacts as she pleads with police to allow her daughter to pass a checkpoint for cancer treatment after she arrived from Hubei province at the Jiujiang Yangtze River Bridge in Jiujiang, China, February 1, 2020. (Photo by Thomas Peter/Reuters)

Chinese paramilitary guards monitoring passengers as they head to their train to travel to their hometowns for the “Spring Festival” or Lunar New Year at Nantong Railway Station in Jiangsu province, near Shanghai Travellers taking part in the world' s largest annual human migration must be home by January 27 to usher in the new year on January 28. (Photo by AFP Photo/Stringer)

Wellcome trust employee Zoe Middleton poses behind an artwork entitled “My Soul” by Katharine Dowson, which consists of a laser etched lead chrystal glass formation in the shape of a brain, and was created using the artists own MRI Scan, at Wellcome Collection on March 27, 2012 in London, England. (Photo by Dan Kitwood/Getty Images)

An employee in a bookshop adjusts packaged cigarettes which have to be sold in identical olive-brown packets bearing the same typeface and largely covered with graphic health warnings, with the same style of writing so the only identifier of a brand will be the name on the packet, in Sydney on December 1, 2012. A new world-first law forcing tobacco companies to sell cigarettes in identical packets came into effect Saturday in Australia in an effort to strip any glamour from smoking and prevent young people from taking up the habit. (Photo by William West/AFP Photo)

The Facebook website is displayed on a laptop computer on May 9, 2011 in San Anselmo, California. An investigation by The Pew Research Center found that Facebook has become a player in the news industry as the popular social media site is driving an increasing amount of traffic to news web sites. (Photo Illustration by Justin Sullivan/Getty Images)

Settled snow is seen covering houses and Cecil Peak on New Zealand's lower South Island on November 4, 2011 in Queenstown, New Zealand. The unseasonal weather is not expected to clear until tomorrow, with snow continuing to fall. (Photo by Teaukura Moetaua/Getty Images)

A prototype of a new nano spaceship is displayed during a press conference held by Israel's Space IL organisation on December 8, 2011 in Ehud, Israel. Israeli President Shimon Peres participated in the event unveiling Space IL's latest prototype nano spaceship with the aim of launching a Israeli robotic spacecraft that will land on the moon and raise funds for scientific education in Israel. (Photo by Ilia Yefimovich/Getty Images)