The common flu shot reactions include swelling, soreness and redness at the point of injection, body aches and low grade fever. Some people are concerned about more serious flu shot adverse reactions. The Center for Disease Control and Prevention (CDC) says that more serious flu shot reactions are rare and that the benefits of vaccination outweigh the risks.
Many doctors and researchers believe that some serious influenza shot adverse reactions occur because of an ingredient called thimerosal. Thimerosal is a mercury-based preservative and a known neuro-toxin, meaning that it damages or destroys nerve cells in the brain. Some researchers believe that there is a link between thimerosal and autism. They believe that a noted increase in autism over the last several years was caused by adverse flu shot reactions.
Some researchers and doctors believe that Alzheimer's disease may also be counted among flu shot adverse reactions. One doctor's research concluded that a person who had five consecutive influenza vaccines between the years 1970 and 1980 was ten times more likely to develop Alzheimer's than a person who had none, one or two. Since Alzheimer's does not develop immediately following a flu shot, there is no solid evidence that it can be counted among flu shot reactions. There is only speculation and theory.
The CDC states that there is "no convincing evidence" that mercury or thimerosal has caused any flu shot adverse reactions other than redness or swelling at the point of injection. For those who are concerned that thimerosal may cause flu shot reactions, preservative free vaccinations are available. Even vaccines labeled preservative free may contain trace amounts of mercury, but the amount is so low that it can not act as a preservative and can therefore be labeled preservative free.
Anyone who is allergic to chicken eggs could have serious flu shot adverse reactions.
The influenza viruses used in the vaccines are grown inside chicken egg cells. The CDC advises that flu shot reactions caused by allergies will occur within the first few hours of receiving the shot. Flu shot adverse reactions caused by allergies may include accelerated heart rate, breathing problems, hoarseness, wheezing, hives, paleness, weakness or dizziness. Anyone with these symptoms should see a doctor immediately.
One of the very rare, but serious flu shot reactions is Guillain-Barre syndrome.Guillain-Barre syndrome may occur as a result of flu shot adverse reactions in one in a million cases. It was first linked to swine flu vaccinations. The syndrome can cause temporary paralysis and sometimes permanent nerve damage. The CDC advises that anyone who developed the syndrome within 6 weeks of receiving a flu shot should not take the vaccine subsequently. Further, anyone who has had flu shot adverse reactions due to allergies in the past should not take the vaccine.
Anyone who experiences anything other than the common flu shot reactions should have their doctor fill out a Vaccine Adverse Event Reporting System form. This form helps the CDC evaluate the safety of the vaccine and make advisements concerning possible flu shot adverse reactions.