AstraZeneca backs its Covid-19 shot as nations battle new surges

Germany has ordered a strict lockdown over Easter to control a spike in cases

Vaccination programmes are being ramped up around the world, including with the shot developed by AstraZeneca and the University of Oxford

AstraZeneca has said it is standing by its coronavirus vaccine after a US agency raised concerns about trial results that showed the shot to be highly effective in preventing Covid-19.

AstraZeneca had published results from its US trials on Monday, showing the vaccine to be 79 percent effective in preventing Covid-19, but the US National Institute for Allergies and Infectious Diseases raised concerns that the results were outdated.