COVID-19 | Nations that hoard possible Covid-19 vaccines while excluding others will deepen the pandemic, World Health Organisation (WHO) chief Tedros Adhanom Ghebreyesus said on Tuesday, issuing a last-ditch call for countries to join a global vaccine pact.

The WHO has an Aug 31 deadline for wealthier nations to join the "Covax Global Vaccines Facility" for sharing vaccine hopefuls with developing countries. Tedros said he sent a letter to the WHO's 194 member states, urging participation.