Indexes close in the negative
The S&P 500 and Dow Jones indices closed lower on Monday as Walt Disney (NYSE:DIS) shares fell, while Alexion Pharmaceuticals jumped on news of a $39 billion takeover offer from AstraZeneca (LON:AZN), which would be one of the biggest deals of the year.
The Pfizer-BioNTech vaccine, was delivered to health facilities across US states on Sunday and mass vaccination began on Monday.
Vaccinations are seen as crucial to ending the COVID-19 pandemic.
Shares in Disney are down 3.65% and Pfizer (NYSE:PFE) is down almost 5%.
Jake Dollarhide from the Longbow Asset Management company said: "While the whole market is happy, optimistic, bullish about the start of vaccination in the US, I think the average investor understands that its application and widespread distribution will not be a wand, will not go as fast as we would like".
Shares in Alexion Pharmaceuticals soared to a 4.5-year high following AstraZeneca's $39 billion takeover offer. AstraZeneca shares are down 8%.
Walt Disney shares fell after BMO Capital Markets downgraded the company following the release of its reports and said Netflix (NASDAQ:NFLX) had once again "won the competition for consumer choice". Netflix shares are up almost 4%.
The Dow Jones Industrial Average fell 0.48% to 29,900.96 points and the S&P 500 fell 0.32% to 3,651.92. The Nasdaq Composite rose 0.61% to 12,453.96.