"The World Health Organization is committed to defeating the coronavirus pandemic with science and public health measures, and supporting the health workers who are on the frontlines of the response", said Tedros Adhanom Ghebreyesus, Director-General of WHO, making Monday's announcement of the event.

The live broadcast – which will air on Saturday, 18 April 2020 and feature the real-life experiences of doctors, nurses and families living through the pandemic will include an all-star line-up of artists curated in collaboration with Lady Gaga.

Among those performing will be Alanis Morissette, Andrea Bocelli, Billie Eilish, Billie Joe Armstrong of Green Day, Burna Boy, Chris Martin, David Beckham, Eddie Vedder, Elton John, FINNEAS, Idris and Sabrina Elba, J Balvin, John Legend, Kacey Musgraves, Keith Urban, Kerry Washington, Lang Lang, Lizzo, Maluma, Paul McCartney, Priyanka Chopra Jonas, Shah Rukh Khan and Stevie Wonder.

Stars align

Jimmy Fallon of 'The Tonight Show', Jimmy Kimmel of 'Jimmy Kimmel Live' and Stephen Colbert of 'The Late Show with Stephen Colbert', will host the event, with friends from Sesame Street on hand to unify and inspire people to support the global COVID-19 response.

Funding pledges from philanthropists and corporate partners will go to the COVID-19 Solidarity Response Fund for WHO to equip frontline health care workers with masks, gowns and other vital equipments, as well as to local charities providing food, shelter and healthcare to those most in need.

UN Secretary-General António Guterres stressed that the entire UN system is fully mobilized, supporting country responses, placing supply chains at the world's disposal and advocating for a global ceasefire. "We are proud to join forces with 'One World: Together At Home' to help suppress the transmission of the virus, minimize social-economic impacts on the global community and work together now to advance Global Goals for the future", he said. "We are in this together and we will get through this together."

Hugh Evans, Co-Founder and CEO of Global Citizen, said the broadcast aims to be a source of unity and encouragement. "Through music, entertainment and impact, the global live-cast will celebrate those who risk their own health to safeguard everyone else's", he said.

Speaking at a press conference in Geneva, Dr. Ghebreyesus announced that WHO is issuing guidance and criteria to help countries decide whether to recommend the use of medical and non-medical masks to prevent the spread of COVID-19.

"First and foremost, medical masks must be prioritized for health workers on the front lines of the response," he said, expressing concern that the mass use of medical masks by the general population could exacerbate the global shortage for people who need them most. "In some places, these shortages are putting health workers in real danger."

In healthcare facilities, WHO continues to recommend the use of medical masks, respirators and other personal protective equipment for health workers. In the community, it recommends the use of medical masks by people who are sick and those caring for a sick person at home.

He said countries could consider using masks in communities where other measures, such as cleaning hands and physical distancing are more difficult to achieve because of lack of water or cramped living conditions. Masks, if worn, must be used safely and WHO has guidance on how to put on, take off and dispose of masks.

What is clear is that there is limited research in this area. He encouraged countries considering the use of masks for the general population to study their effectiveness. "Mask or no mask, there are proven things all of us can do to protect ourselves and others. Keep your distance, clean your hands, cough or sneeze into your elbow, and avoid touching your face."

'One World: Together At Home' will broadcast live on Saturday, April 18, 2020 at 5pm, PDT/8pm, EDT/12am GMT airing on ABC, NBC, ViacomCBS Networks, iHeartMedia and Bell Media networks and platforms in Canada.

Internationally, UK-based channel BBC One will run a version of the programme on Sunday April 19, 2020. Additional international broadcasters include beIN Media Group, MultiChoice Group and RTE.

It will also be a multi-hour digital broadcast streaming online on multiple global platforms, including: Alibaba, Amazon Prime Video, Apple, Facebook, Instagram, LiveXLive, Tencent, Tencent Music Entertainment Group, TIDAL, TuneIn, Twitch, Twitter, Yahoo and YouTube.