The U.S. Centers for Disease Control and Prevention, or CDC, recommends influenza vaccinations for almost everyone over the age of six months for the 2010-2011 flu season. The intranasal, or nasal spray, form of the vaccine contains three strains of live attenuated, or weakened, flu virus. In addition to the 2009 H1N1 virus that caused the 2009 epidemic, the nasal spray includes an influenza B strain and an H3N2 virus. These live viruses can cause some significant side effects.
Fever
Fever is a common complaint after the flu nasal spray, and Consumer Reports suggests using acetaminophen or ibuprofen to control body temperature. Any high fevers or persistent temperature elevations should be reported to the doctor.
Gastrointestinal Problems
Children may complain of mild abdominal pain, vomiting or diarrhea after receiving the intranasal flu vaccine. If these symptoms worse or persist, contact the child's physician.
Respiratory Complaints
The CDC says children and teens may have mild cough, running nose or nasal congestion after receiving the nasal flu spray. Adults may experience these symptoms along with a sore throat. If these effects continue or worsen, notify a health care provider, Consumer Reports recommends. The live form of influenza vaccine is contraindicated in individuals with cerebral palsy or seizure disorders who can't handle additional breathing problems.
Anaphylaxis
Because the flu vaccine is grown in eggs, people with significant allergies to eggs or egg products may develop a life-threatening allergic response called anaphylaxis within a few minutes to a few hours after receiving the nasal flu vaccine. Contact emergency medical services for facial and lip swelling, hives, weakness, dizziness or difficult breathing, says the CDC.
Neurological Complications
The flu nasal spray has been associated with mild neurological symptoms like headache, which should go away with acetaminophen or ibuprofen. The live vaccine is also linked to more serious symptoms like irritability, marked fatigue or weakness, listlessness and significant behavioral changes. If these symptoms occur, seek medical care immediately, says Consumer Reports.
Overwhelmed Immune System
The nasal flu vaccine contains weakened flu viruses that can't cause influenza in healthy individuals, according to the CDC. However, the live intranasal vaccine is not approved for people with weakened immune systems, those with chronic health conditions like asthma or diabetes, children under the age of 2 years, adults over the age of 50 or others whose immune systems can't respond effectively to the vaccine.
