According to the Centers for Disease Control and Prevention (CDC), influenza affects 5 to 20 percent of the population each year. The best way to prevent seasonal flu is to get vaccinated every year. The flu vaccine is available as an intramuscular injection (shot) or as an intranasal spray. Both types have potential symptoms that should be considered when scheduling an appointment for a flu vaccination.
Local Site Reaction
Both the injection and the intranasal vaccine are associated with local site reactions. For the injection, up to 64 percent of adults and children complained of injection site reactions consisting of localized muscle pain, tenderness, redness and swelling, which according to product literature provided by FDA-approved vaccine manufacturer Sanofi-Pasteur, persisted for up to 2 days. For the intranasal vaccine (Flu Mist), manufacturer MedImmune reported that more than 10 percent of adults and children complained of runny nose or nasal stuffiness after being vaccinated.
Flu-like Symptoms
More than 10 percent of people who receive the flu vaccine report transient mild flu-like symptoms. In clinical studies done by CSL Biotherapies Inc., makers of the Afluria seasonal flu vaccine, the most common complaints were headache (26 percent), malaise (20 percent), generalized muscle aches (13 percent), nausea (6 percent), chills or shivering (3 percent), temperature above 99.9 degress F (1 percent) and vomiting (1 percent).
Among people who received the intranasal vaccine, according to manufacturer MedImmune LLC., the most common symptoms were runny nose (44 percent), headache (40 percent), sore throat (28 percent), tiredness or weakness (26 percent), muscle aches (17 percent), cough (14 percent) and chills (6 percent).
For both vaccines, children reported a broader range of symptoms, including irritability, rhinitis, fever, loss of appetite, vomiting, diarrhea, headache, muscle aches and sore throat.
Guillain-Barre Syndrome
Guillain-Barre syndrome (GBS) is an autoimmune disease in which the body makes antibodies that attack sites on the peripheral nerves. One in 100,000 people who received the swine flu vaccine in 1976 and one to two in a million people who received the seasonal flu vaccine between 1992 and 1994 developed GBS.
According to the National Institute of Neurological Disorders and Stroke, the initial symptoms of GBS include muscle weakness and tingling that begins in the legs and moves progressively up the body. In severe cases, a person may be completely paralyzed and require mechanical ventilation to breathe because of paralysis of the diaphragm. In 90 percent of patients, symptoms peak at approximately three weeks. Between 5 and 6 percent of people with GBS die. Among those who survive, recovery often takes months, and nearly one third of patients report residual weakness up to 3 years later.
