An influenza vaccine, commonly referred to as a flu shot, is a dose of inactivated flu virus that can help prevent influenza. The Centers for Disease Control, or CDC, recommends that children, pregnant women, people over age 50 and people of all ages who have a chronic health condition be vaccinated against the flu each year. While most side effects, such as soreness or a low-grade fever, are mild and resolve quickly, there are a few rare and potentially serious side effects of the influenza vaccine that you should be aware of.
Allergic Reaction
The CDC reports that rarely, a severe allergic reaction may occur after vaccination with the flu shot. Symptoms of such a reaction include wheezing, dizziness, hives and trouble breathing. People who are allergic to eggs may be at a higher risk of an allergic reaction than the general population, and should not receive the influenza vaccine. If you notice any of these symptoms after a vaccine, seek emergency care immediately, and be sure to tell all doctors who may give you a vaccine in the future.
Guillain-Barre Syndrome
Guillain-Barre syndrome, or GBS, is another possible yet very rare complication of the influenza shot. GBS can occur after any type of illness as well as after a vaccine. Symptoms include weakness, tingling, difficulty speaking and swallowing, low blood pressure and lack of bladder control. There is no cure for GBS, but the Mayo Clinic states that most cases resolve within a year. Treatments that may speed up the recovery period include plasma exchange and intravenous immunoglobulin.
Oculorespiratory Syndrome
According to the CDC, occasionally symptoms affecting the eyes or respiratory system present themselves after a patient receives an influenza vaccine. Oculorespiratory syndrome, or ORS, is characterized by the development of one or more symptoms within 24 hours of receiving the vaccine. These symptoms include red eyes, facial swelling, wheezing, difficulty breathing and sore throat. If you have these symptoms, you should report them to your doctor so that a report can be filed with the Vaccine Adverse Effects Reporting System (VAERS). Most people who develop ORS after one flu vaccine can be revaccinated at another time without incident.
