The Duke and Duchess of Sussex have asked supporters to make a donation to a vaccine equity campaign to mark their son Archie's second birthday.
Eschewing the traditional release of a new photograph to mark the occasion, the couple instead urged the public to give money to a global vaccine-sharing scheme, stating that "even a small contribution can have a ripple effect."
They said: "We cannot think of a more resonant way to honor our son’s birthday. If we all show up, with compassion for those we both know and don’t know, we can have a profound impact.
"Together, we can uplift, protect, and care for one another."
Donations will go Gavi, the Vaccine Alliance that co-founded Covax, which is distributing the coronavirus vaccine to the developing world.
The move is in stark contrast to the way they chose to mark Archie's first birthday, when they released a touching video of the Duchess, 39, reading the toddler a story, Duck! Rabbit!
It is also a notable contrast to the way the Duke and Duchess of Cambridge mark their own children's birthdays by releasing a new photograph usually taken by the Duchess.
In a statement posted on their Archewell website, the Sussexes said they had been "deeply touched" by the warmth and support shown for their family since Archie was born.
They said they were incredibly grateful to all those who donate to charities on his behalf or "mark the occasion by giving back or doing an act of service — all through the goodness of your hearts."
They said that although in some places, it felt that "normalcy is around the corner", others continue to suffer from the impact of the pandemic.
"We will not be able to truly recover until everyone, everywhere, has equal access to the vaccine," they said.
"And with that intention, we are inviting you to contribute whatever you can — if you have the means to do so — to bring vaccines to families in the world’s most vulnerable places.
"For a donation of just $5, you can cover the cost of a dose for someone in need. And because we were able to secure matching support from a number of organisations, that $5 you give will automatically turn into $20 — covering the cost of four doses. Every single dollar counts — not only will it help save lives but it will help save families and communities."
The couple were last week named “campaign chairs” of Vax Live, a star-studded event in Los Angeles billed as “the concert to reunite the world.”
The Duke appeared on stage at the concert last weekend to promote the vaccine and call on businesses to “donate dollars for doses”.
The event, featuring an array of celebrities and politicians from US President Joe Biden to Jennifer Lopez, was likened to LiveAid, the 1985 concert that raised millions for famine relief in Africa.
The heavily pregnant Duchess has pre-recorded a message that will be shown in the televised broadcast of the event in the US on Saturday.
Archie Harrison Mountbatten-Windsor was born on May 6 2019 at 5.26am, weighing 7lb 3oz.
A few days after his birth, his parents proudly showed him to the world, before the Queen and Duke of Edinburgh were introduced to him for the first time.
Meghan's mother, a yoga instructor and social worker, was pictured at the gathering and she has been a constant presence in the Sussexes' lives.
The Royal family has not seen Archie since autumn 2019, shortly before they left the UK but posted messages on social media on Thursday with pictures of him as a baby.
The Queen and the Prince of Wales wished Archie "a very happy 2nd second birthday" while the Prince of Wales and the Duchess of Cornwall, as well as the Duke and Duchess of Cambridge, all posted celebratory messages.
Meghan recently revealed her son and husband and their special bond was the inspiration behind her first children's publication, The Bench.