1 / 10Volunteers of Pfizer's coronavirus vaccine candidate have reported 'severe' hangover after receiving the first shot of the vaccine and said it left them with headaches, fever and muscle aches.2 / 10The side effects such as 'severe hangover', headache and muscle pain from the Pfizer coronavirus vaccine have been reported days after the US pharmaceutical giant and its German partner, BioNTech, announced the vaccination was 90 per cent effective against the Covid-19 infection.3 / 10According to a report by Daily Mail, Pfizer has enrolled more than 43,500 people in six countries as volunteers for the clinical trials of its coronavirus vaccine in the hunt for an effective drug against the Covid-19 infection.4 / 10Several volunteers have reported side effects like 'severe hangover' and 'headache' and also said the Pfizer coronavirus vaccine shots 'left them aching all over'.5 / 10A volunteer, Glenn Deshields, 44, said the Pfizer vaccine shot made him feel like he had a 'severe hangover'. But, he said, the symptoms quickly cleared up6 / 10Another volunteer, identified as Carrie, said she received her first shot of the Pfizer coronavirus vaccine way back in September and another in October.7 / 10Carrie said she experienced a 'headache, fever and aches all over her body'. After the second shot, these became 'more severe', she was quoted as saying by the report. Another volunteer, Deshields said he suffered side effects similar to a 'severe hangover'.8 / 10Pfizer on Monday declared that an early peek at its vaccine data suggests the shots maybe 90 per cent effective at preventing Covid-19, indicating the company is on track later this month to file an emergency use application with US regulators.9 / 10Pfizer Inc PFE.N Chief Executive Officer Albert Bourla sold $5.56 million worth of company shares on Monday, the day the drugmaker said its coronavirus vaccine was 90 per cent effective based on interim trial results, a regulatory filing showed.10 / 10Bourla authorized the sale of the shares on Aug. 19, provided the stock was at least at a certain price, as part of a predetermined plan, the company said. Bourla sold 132,508 shares at $41.94 per share, according to a Securities and Exchange Commission filing late Tuesday. Israel will sign a provisional deal with Pfizer Inc PFE.N on Friday to receive 8 million doses of the drugmaker's still-experimental coronavirus vaccine from January, the Israeli health minister said.