Vaccine Safety Monitoring Ensures Continued Safety, Part 2 of 3

October 27, 2010

By Claudia Vellozzi, M.D., M.P.H., Deputy Director, Immunization Safety Office, Centers for Disease Control and Prevention, HHS

In my previous post, I introduced vaccine safety monitoring as one of the high standards set by the United States for the safety of flu vaccines. Vaccine safety monitoring is an important part of the annual influenza vaccination program. Safety monitoring allows us to detect any potential adverse events as early as possible to help ensure that influenza vaccination remains safe. The two systems that have been used over the years to monitor vaccine safety are the Vaccine Adverse Event Reporting System (VAERS) and the Vaccine Safety Datalink (VSD).

• VAERS is a voluntary reporting system that helps us to look for possible safety concerns. VAERS receives reports from anyone who experienced or is aware of a health problem following vaccination. VAERS can detect potential concerns that can be studied in other systems, but VAERS alone generally cannot determine if a vaccine caused an adverse event.
• VSD is a collaboration between CDC and 8 health systems that include immunization and health information for about 9 million people. VSD can be used to help determine whether a vaccine is associated with an adverse event.

Data from studies conducted over the past 2 decades, including studies using information from VAERS and VSD, show that influenza vaccines have a strong track record for safety and have been safely given to millions of people. This was also true of the 2009 H1N1 influenza vaccine; more than 80 million doses of 2009 H1N1 vaccine were given and we found the safety profile was consistent with previous seasonal influenza vaccines.

In my next post, I will share some of the results from a VAERS study on the 2009 H1N1 flu vaccination.