Major Differences Between TIV and LAIV

Influenza Prevention and Control Recommendations

Published for the 2010-11 Influenza Season; Adapted for the 2011-12 Influenza Season

TIV contains inactivated viruses and thus cannot cause influenza. LAIV contains live attenuated influenza viruses that have the potential to cause mild signs or symptoms related to vaccine virus infection (e.g., rhinorrhea, nasal congestion, fever, or sore throat). LAIV is administered intranasally by sprayer, whereas TIV is administered intramuscularly by injection. LAIV is licensed for use among nonpregnant persons aged 2-49 years; safety has not been established in persons with underlying medical conditions that confer a higher risk for influenza complications. TIV is licensed for use among persons 6 months and older, including those who are healthy and those with chronic medical conditions.

During the preparation of TIV, the vaccine viruses are made noninfectious (i.e., inactivated or killed) (8). Only subvirion and purified surface antigen preparations of TIV (often referred to as "split" and subunit vaccines, respectively) are available in the United States. Standard-dose TIV preparations contain 7.5 mcg HA antigen per vaccine strain (for children aged <36 months) or 15 mcg of HA antigen (for persons aged ≥36 months) per vaccine strain (i.e., 22.5 mcg or 45 mcg total HA antigen).

Information about a new formulation of trivalent inactivated vaccine that is given intradermally (into the skin) for adults aged 18 through 64 years is available in the 2011-2012 recommendations.