The Duke and Duchess of Sussex were both set to join famous names in music, film and politics at the Vax Live event in California.
But while Harry made his first public appearance since his grandfather Prince Philip’s funeral to address the crowd, his partner did not join him in person.
He received a standing ovation from the crowd, before delivering a speech praising the selfless efforts of frontline workers during the pandemic.
“Tonight is a celebration for all of you here, the vaccinated frontline workers in the public and the millions of frontline heroes around the world,” he told the audience.
“You have spent the past year bravely and selflessly fighting to protect us all.
“You have served and sacrificed, you have put yourself in danger and you have acted courageously, knowing the costs. We owe you an incredible debt of gratitude. Thank you. “
The couple serve as campaign chair for the event, encouraging donations to Covax, an organization that works to provide vaccines for low- and middle-income countries.
Hosted by Selena Gomez, the show is scheduled to air on May 8 with musical performances by Jennifer Lopez and Foo Fighters.
Other famous guests include Ben Affleck, Chrissy Teigen and talk show host Jimmy Kimmel.
US President Joe Biden and First Lady Jill Biden also made an appearance at the event, with a video message.
Harry and Meghan said in a joint statement ahead of the event: “Over the past year our world has experienced pain, loss and struggle – together. We must now recover and heal – together.
“We cannot leave anyone behind. We will all benefit, we will all be safer, when everyone, everywhere, has equal access to the vaccine.
“We must pursue a fair distribution of vaccines and, in this, restore faith in our common humanity. This mission could not be more critical or more important. “
Harry recently returned to the UK to attend the funeral of his grandfather, the Duke of Edinburgh.
Meghan remained in the United States, having been advised not to fly during the pregnancy of their second child.