Prince Harry and Meghan Markle have used their son Archie’s second birthday as a fundraising call for “vaccine equity.”

Accompanying a filtered new photograph of Archie, with his back to the camera and holding balloons, Harry and Meghan write on the website for their charity Archewell: “We have been deeply touched over the past two years to feel the warmth and support for our family in honor of Archie’s birthday. Many of you donate to charities on his behalf, and mark the occasion by giving back or doing an act of service—all through the goodness of your hearts. You raise funds for those who need it most, and continue to do so organically and selflessly. We remain incredibly grateful.”

The couple write of the impact of the coronavirus pandemic. “As of today, around 80 percent of the nearly one billion COVID-19 vaccine shots that have been given were administered in wealthier countries. While we may feel that normalcy is around the corner, we remind ourselves that in much of the world, and especially in developing countries, vaccine distribution has effectively yet to start.”

Asking the reader “to contribute whatever you can—if you have the means to do so,” Harry and Meghan say they want “to bring vaccines to families in the world’s most vulnerable places.” A donation of $5, through charitable matching, becomes $20—the equivalent of four vaccine doses, they say.

“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. Even a small contribution can have a ripple effect. Together, we can uplift, protect, and care for one another.”

The rest of the royal family—including the queen, Prince Charles, and Prince William and Kate Middleton—wished Archie happy birthday on social media.