It’s dog eat dog in the world of COVID-19 vaccines.

That’s the fear of global health agencies planning a scheme to bulk-buy and equitably distribute vaccines around the world. They are watching with dismay as some wealthier countries have decided to go it alone, striking deals with drugmakers to secure millions of doses of promising candidates for their citizens.

The deals - including those agreed by the United States, Britain and the European Union with the likes of Pfizer, BioNtech, AstraZeneca and Moderna - are undermining the global drive, experts say.