Flu shots are most effective at preventing severe influenza with complications. People who live with or provide care to those at high-risk including doctors, nurses, therapists, etc. Anyone who wishes to reduce their risk of influenza and its complications. The vaccine virus is grown in eggs and a trace of egg protein may remain in the final vaccine. People with severe egg allergy should be vaccinated only if their health care provider believes it is necessary and if the vaccine is given under close observation by a health care provider.
Most people have little or no reaction to the vaccine.
One in four might have a swollen, red, tender area where the vaccination was given. A much smaller number might also develop a slight fever within 24 hours and many have chills, a headache, or feel a little sick. This occurs more often in children than adults. People who already have a respiratory disease may find their symptoms worsened. Usually none of these reactions lasts for more than a couple of days.