The event, led by the World Health Organization (WHO) and the nonprofit group Global Citizen, told the personal stories of teachers and healthcare, grocery, delivery, postal and other workers.
All those taking part in the event will appear remotely due to social distancing and shutdowns aimed at curtailing the spread of the disease that has killed more than 124,000 people worldwide.
"I grew up in a world where a woman who looks like me — with my kind of skin and my kind of hair — was never considered to be beautiful," said Miss Universe Zozibini Tunzi.
Posen founded the company in 2001 at the age of 20.
Effective mentoring can make youths into leaders.
Winfrey has had a positive relationship with Jewish leaders and the Jewish state stretching back at least a decade.
A powerful Golden Globes speech - and a slew of jokes - set off a wave of speculation.