British Prime Minister Boris Johnson described early stage clinical trial data on an AstraZeneca COVID-19 vaccine as very positive on Monday. 'This is very positive news. A huge well done to our brilliant, world-leading scientists & researchers at @UniofOxford,' Johnson said, on Twitter, linking to a report on the data. 'There are no guarantees, we're not there yet & further trials will be necessary - but this is an important step in the right direction.'
