Liam Neeson, Orlando Bloom and Priyanka Chopra Jonas were among the signatories to the letter
Nearly 30 celebrities, from singer Katy Perry to footballer David Beckham, called on the G7 Tuesday to share Covid-19 vaccines with poorer countries ahead of a summit in Britain this weekend.
The entertainment and sports figures urged the seven countries - France, Italy, the UK, Canada, Japan, Germany, and the United States - to pledge at least 20% of their supply between June and August, amounting to 150 million doses.
"The world has spent a year and a half battling the Covid-19 pandemic, but the virus is still spreading in many countries and producing new variants with the potential to put us all back where we started," the missive warned.
"This means more school closures, more healthcare disruptions, and greater economic fallout -- threating the futures of families and children everywhere," it said.
Among the other signatories on the letter, which included a number of UNICEF goodwill ambassadors, were actors Liam Neeson, Orlando Bloom, Priyanka Chopra Jonas, and Whoopi Goldberg.
Singers Billie Eilish and Angelique Kidjo plus football star Sergio Ramos, Formula One driver Fernando Alonso and tennis star Andy Murray also signed the letter.
Britain is hosting the G7 summit in Cornwall in southwestern England starting Friday.