MONEYWEB app instead? The world needs single servings. By Emma Court, Bloomberg 2 May 2021 08:49 Image: Bloomberg The rapid development of Covid-19 vaccines is one of medicineâs greatest achievements, but distribution hasnât been easy. Vials full of doses often must be kept in extreme cold, and once opened have to be used quickly, sometimes prompting health workers to run out into the street looking for someone to take the leftovers. Now vaccination campaigns in the US and some other countries are moving from mass demand to more targeted efforts to reach the hesitant — and doctors want easier ways to deliver shots.