Prince Harry and his wife, Meghan Markle, have issued an open letter to G20 leaders urging them to share surplus Covid-19 vaccines with low-income nations.
The couple on Friday published the joint letter, written with Dr Tedros Adhanom Ghebreyesus, director general of the World Health Organisation.
The leaders of the world's 20 biggest economies are meeting at the G20 summit in Rome at the weekend.
In June, the world's wealthiest nations made pledges at the G7 Summit to provide more than one billion doses of Covid-19 vaccines to low- and middle-income countries to help vaccinate the world.
But the WHO says only 150 million of the 1.3 billion doses have been received.
In addition, the WHO says almost seven billion doses have been administered globally but only 3 per cent of people in low-income countries have received a dose so far.
The letter from the Duke and Duchess of Sussex and the WHO urged G20 leaders to issue doses as swiftly as possible.
“Promises aren’t translating into vaccines reaching the people that need them,” they wrote.
“Among countries represented at the G20, there are a handful with millions of surplus vaccines that are destined to be wasted once they expire.
“Every discarded dose of a Covid-19 vaccine, when there are the mechanisms to donate them, should outrage us all. Each dose represents a real person — a mother, father, daughter, or son — who could have been protected.”
The letter added that despite differences, everyone at the summit shared “a common goal: to tackle global inequity".
“Today, we join with others to urge global leaders to end this devastating inequity and end this pandemic once and for all,” it said.
“We must do everything in our power to get doses to as many people who want and need them, as fast as possible, in the right order, and to have the greatest possible impact.”
Decisions made at the G20 summit this weekend may “make or break” the global target of vaccinating 40 per cent of all countries by the end of 2021, the letter said.
The Duke and Duchess of Sussex and Dr Tedros urged nations to “immediately close the 550 million-dose gap” to accelerate towards the 40 per cent coverage target by speeding up existing commitments of dose donations, pledging new ones and eliminating export restrictions on vaccines.
The letter also called on pharmaceutical companies to be held to “higher transparency standards” by including publicly shared monthly production projections and delivery schedules to help countries better plan to receive and share doses.
It also called for vaccine technology to be shared and for vaccine production barriers to be dismantled.
“We understand that the pandemic recovery is nuanced and deeply complex, but we have a window of opportunity to come together as a global community and meet our humanitarian promises,” the letter said.
“By delivering already-pledged doses, helping countries manufacture their own vaccines and prioritising vaccines for nations in need, the G20 can help ensure the world delivers on these promises.”
If the virus is allowed to spread through unvaccinated populations, the letter said, the risk of the development of new and more deadly strains increases.
“There are many crises that you — the stewards of our planet — must grapple with this weekend: the climate emergency, the state of our global economy, a recommitment to multilateralism. Yet, in many ways, making headway on these priorities depends on whether we can beat this pandemic.
“Co-operation of historic proportion is the only solution. Lives literally depend on it.”