Reduced-dose influenza vaccine

To evaluate the effectiveness and safety of reduced-dose trivalent inactivated influenza vaccine in adults.

A MEDLINE search was conducted (1966-May 2006) using the key search terms inactivated, trivalent, influenza vaccine, dose, and intradermal.

Four recent studies evaluated the safety and effectiveness of reduced-dose, inactivated, trivalent influenza vaccine. Reduced doses had immunogenicity similar to that of standard dose vaccination in healthy individuals less than 60 years old. Intramuscular administration caused fewer local adverse effects compared with the other routes of administration. The differences in vaccine administration and dosing used in these studies limit the comparison of their results.

The Centers for Disease Control and Prevention does not recommend vaccinating with reduced-dose influenza vaccine. If reduced-dose vaccination is to be employed during times of vaccine shortage, it should be administered only to healthy adults under the age of 60, and the intramuscular route is preferred.