A British report has revealed that at least 10 people have died in 2011 following side-effects after being administered the flu vaccine.
In 2011, there were 10 deaths linked to the vaccine, compared with 18 during 2008-2010, the Daily Express reported.
In total, 458 cases of suffering from side-effects were reported last year, up four-fold from a total of 108 cases in 2009.
The side-effects include asthma attacks and chest infections.
The Medicines and Healthcare Products Regulatory Agency, however, said the increase may be because more people are logging their concerns rather than an actual rise in adverse reactions.
The Department of Health said serious side-effects of the flu vaccine were rare but warned people they may have a slight temperature and aching muscles for a few days after the jab.
The department said vaccination remained the best way to protect against a number of life-threatening diseases, including flu. Last year, more than 10 million doses of flu vaccine were given out in England, but there were just 0.004 percent reports of side-effects.