AstraZeneca shares trade at early November levels on vaccine data questions       

AstraZeneca is likely to run an additional global trial to assess the efficacy of its vaccine using a lower dosage

Questions about the data from AstraZeneca's phase 3 trial have raised the possibility that early approval of the vaccine may be delayed

Shares in AstraZeneca, the British drugs firm that is developing a vaccine with Oxford University, rose slightly on Friday but continue to trade below levels of early November, as questions emerged about the way it announced the results of its phase 3 trial earlier in the week.                      

The World Health Organisation (WHO) needs to evaluate coronavirus vaccines and their immune responses based on more than just a press release, Kate O’Brien, WHO’s director of immunisation vaccines and biologicals, said on Friday.