The dollar has dropped over 2.2% so far this month as global market sentiment has soared on Joe Biden’s US election victory and news of progress in the development of coronavirus vaccines, lowering demand for the safe-haven currency.But sentiment became more mixed after numerous scientists increased concerns regarding the success rate for the vaccine developed by British drugmaker AstraZeneca.AstraZeneca announced on Monday that its vaccine was 70% efficient in pivotal trials, and could possibly be up to 90% effective-the most recent in a slew of positive vaccine announcements which had fueled investor confidence.At 0831 GMT, the dollar was at 91.953 in opposition to a basket of currencies, down 0.1% on the day and close to its lowest in three months. Market price-action was limited on Thursday by the Thanksgiving holiday in the US, which will be operating on lessened trading hours on Friday.