2008 - 2009 Influenza Vaccine Strains

Both the inactivated and the live, attenuated influenza vaccine prepared for the 2008--09 season will include:

• an A/Brisbane/59/2007 (H1N1)-like virus;
• an A/Brisbane/10/2007 (H3N2)-like virus;
• a B/Florida/4/2006-like virus.

These viruses will be used because they are representative of influenza viruses that are anticipated to circulate in the United States during the 2008--09 influenza season and have favorable growth properties in eggs.

The inactivated influenza vaccine (the "flu shot") is FDA-approved for persons aged >6 months, including those with high-risk conditions, whereas the live, attenuated influenza vaccine (the nasal-spray flu vaccine) is FDA-approved for use only among healthy persons aged 2--49 years. All children aged 6 months through 8 years who are receiving flu vaccine for the first time should receive 2 doses of vaccine.  Children 6 months through 8 years who received flu vaccine for the first time during the previous influenza season, and got only one dose, should receive 2 doses this season.  Children who were given influenza baccine during any other prior flu season should receive only one dose, however.