Scientific studies and ongoing monitoring continue to show that flu vaccines are safe for use and offer the best defense modern medicine currently has at its disposal to protect against the flu and its serious complications. These vaccines protect against the three influenza viruses that experts predict will be most common during the upcoming season. The 2011-2012 flu vaccine protects against an influenza A (H3N2) virus, an influenza B virus, and the 2009 H1N1 influenza virus.
The CDC reports that the flu vaccines are safe for pregnant women, that they do not cause miscarriage during pregnancy and can be given during any trimester. However, it is recommended that pregnant women do not use the nasal spray vaccine.
Some people should not get the flu vaccine such as children younger than six months old and anyone who has ever had a severe allergic reaction to a flu vaccine. People with known severe allergic reactions to eggs should consult with a doctor with expertise in the management of allergic conditions before receiving a flu vaccine. And, a history of Guillain-Barré syndrome (GBS) that occurred within six weeks after receiving a flu vaccine is considered to be a precaution for receipt of flu vaccines.
The CDC and FDA are monitoring the safety of 2011-2012 flu vaccines through the Vaccine Adverse Event Reporting System (VAERS). VAERS is the nation's frontline system to detect potential vaccine safety problems. VAERS receives reports from anyone who knows about or has experienced a health problem following flu vaccination. Although VAERS cannot determine if a flu vaccine caused a health problem (or adverse event), the system can detect patterns of potential concern that might require investigation. The CDC also manages the Vaccine Safety Datalink (VSD) Project. The VSD Project contains information on more than nine million people and is used to assess whether certain health outcomes are more likely to occur after flu vaccination than would be expected. VSD also is used to conduct other immunization safety studies when needed, as indicated by medical literature reviews, reports to VAERS, changes in immunization schedules, or the introduction of new vaccines. See the FDA announcement.