The Pass The Mic project from the ONE Campaign aims to highlight the need for a global response to the COVID-19 crisis and will see stars give experts and frontline workers a direct line to their millions of followers to help spread the word.
Stranger Things actress Brown, 16, has over 33 million followers on Instagram.
She is among the celebrities who will be handing over their accounts for one day, telling their fans, “The last person you need to hear from right now is me.”
Experts including David Anderson, director of quality at Nightingale Hospital, Manchester, and Aya Chebbi, youth envoy of the African Union, will be on hand to explain why a global effort will be crucial in order to eradicate the virus.
Specialists such as Jen Kates of Global Health & HIV Policy will share their views, based on data, science and facts, in a bid to raise awareness of what is going on on the frontline in the battle to beat the disease.
Oscar-winning actress Julia Roberts, 52, will be the first celebrity to Pass The Mic, handing her 8.7 million followers over to American infectious disease expert Dr Anthony Fauci on Thursday 21 May.
Other stars who will be taking part include Penelope Cruz, Shailene Woodley, David Oyelowo, Alan Cumming, Naomi Ackie and Robin Wright.
Rita Wilson, who along with her husband Tom Hanks recently recovered from coronavirus, is also reported to be taking part.
ONE is a global movement campaigning to end extreme poverty and preventable disease by 2030.
The #passthemic takeovers will continue on Instagram, Facebook and Twitter throughout May and into June.