Meghan Markle and Prince Harry co-signed a letter with the World Health Organisation (WHO) in a bid to get the “wealthiest” countries to help vaccinate the world’s population and end the COVID-19 pandemic.Last month, the Duke and the Duchess of Sussex announced that they had partnered with the WHO in order to open a “dialogue on the urgent need to achieve global vaccine equity.”In a letter co-signed by the WHO’s Director-General, Dr Tedros Adhanom Ghebreyesus, the former royals demanded leaders from richer nations that will be present at this year’s G20 summit, to “end the Covid crisis” by “working to vaccinate the world's population”.