Prince Harry and Meghan Markle just called out the entire G20 for this important reason

The Duke and Duchess of Sussex are determined to do things their way.

After stepping down from their roles as senior working royals and swapping Frogmore Cottage for sun-soaked Montecito, the couple have been exploring different ways to use their celebrity for the good of others – from launching their global nonprofit, Archewell Foundation, to their appearance at Global Citizen Live, in which they called for vaccine equity.

Now, the Sussexes have penned a candid open letter to G20 leaders claiming that promises of vaccine donations from nations are not reaching the globe's most vulnerable.

Ahead of the two-day G20 summit, which will see leaders from the world's richest nations convene in Rome this weekend, Meghan and Harry called said leaders out for lack of action on the issue of vaccine equity, writing that access to the COVID-19 vaccine is a "fundamental human right".

Though environmental issues are expected to be high on the G20 agenda ahead of COP26 kicking off in Glasgow on Sunday, the world's recovery from the pandemic is also likely to be a point of discussion at the summit.

Co-authoring the letter with Dr Tedros Adhanom Ghebreyesus, the WHO director-general, Meghan and Harry certainly didn't mince their words, writing: "When the leaders of the world's wealthiest nations met at the G7 Summit in June, they collectively announced that one billion doses of COVID-19 vaccines would be sent to low and-middle-income countries to help vaccinate the world.

"Pharmaceutical companies have pledged almost the same. Yet, as several nations still don't even have enough vaccines for their own health workers, the world is left asking, where are the doses?

The letter found high profile supporters in the likes of Dr Seth Berkley of Gavi, the Vaccine Alliance, and Chelsea Clinton of the Clinton Foundation.

This is far from the Sussexes' first time using their platform to pressure political leaders, though.

Just last week, Meghan made headlines for an open letter she penned to US Congress, in which she called for paid parental leave as a national right, and opened up about her own early career financial struggles, writing: 'I worked all my life and saved when and where I could – but even that was a luxury – because usually it was about making ends meet and having enough to pay my rent and put gas in my car.'

Sadly, Meghan and Harry will not be attending COP26 in Glasgow next week, though other senior royals, including the Duke and Duchess of Cambridge, will undertake a number of engagements at the summit. Her Majesty the Queen will also miss the landmark event, following doctors' advice to rest for the next two weeks.