By Devik Jain
(Reuters) - London stocks slipped on Friday, set for their first weekly loss this month on doubts over the efficacy of AstraZeneca's COVID-19 vaccine and concerns over a post-Brexit trade deal with the European Union.
The blue-chip FTSE 100 index fell 0.7%, while the domestically focussed mid-cap FTSE 250 lost 0.9%, with industrial, consumer staples and real-estate stocks among the biggest drags.
A Bloomberg report said AstraZeneca was likely to run an additional global trial to assess the efficacy of its COVID-19 vaccine using a lower dosage, amid questions over the results of its late-stage study. The drugmaker's shares were down 0.1%.
"The positive developments surrounding the three leading vaccine candidates formed a metaphorical three-legged stool on which risk appetite rested. But signs that one of those legs could be coming loose, triggered a wobble in risk assets," said Han Tan, market analyst at FXTM.
"The market reaction of late underscores how sensitive investor sentiment is to news surrounding the COVID-19 vaccine."
UK shares have sharply rebounded from their October fall in the past three weeks on vaccine cheer, but concerns over a hit to economic growth from a double whammy of surging coronavirus cases and stalemate over a Brexit-trade deal have pushed both the indexes for the first weekly loss in four.
EU's chief negotiator Michel Barnier said differences on fisheries, state aid and future dispute resolution remain in Brexit trade talks, as he was set to travel to London late on Friday in a last-ditch attempt to clinch a trade deal.
In company news, Daily Mirror publisher Reach Plc jumped 4.3% after saying its 2020 performance was above market expectations, bolstered by strong digital growth.
Marks and Spencer (LON:MKS) fell 2% after Goldman Sachs (NYSE:GS) downgraded the company's shares to "neutral".
Pub operator J D Wetherspoon slipped 2.5% after saying its 366 pubs will remain closed.