Nasal flu vaccine beats shots for young children

By Anthony J. Brown, MD

NEW YORK (Reuters Health) - A new vaccine called CAIV-T that is squirted into the nose offers greater protection against influenza infection in children than does the current FDA-approved injectable vaccine, according to study findings presented this week at the Pediatric Academic Societies meeting in San Francisco.

CAIV-T, short for Cold Adapted Influenza Vaccine Trivalent, is closely related to the already approved nasal vaccine FluMist. The major difference is that the newer vaccine is now refrigerator stable and capable of being easily stored.

In the largest head-to-head flu vaccine study ever conducted, 8457 children, between 6 months and 5 years of age, were randomly assigned to receive CAIV-T or injectable flu vaccine. The bulk of subjects had never been vaccinated before.

"CAIV-T was dramatically more effective than the injectable vaccine," lead researcher, Dr. Robert Belshe, from St. Louis University, told Reuters Health. The number of confirmed flu cases in the CAIV-T group was less than half that seen in the injectable vaccine group, he added.

Compared with the injectable vaccine, CAIV-T provided better protection against circulating flu strains that matched, as well as those that did not match the recommended vaccine strain. CAIV-T was particularly effective against these latter "mismatched" flu stains, Belshe noted.

Given its close similarity to FluMist, the approval process for CAIV-T could be accelerated, Dr. Belshe said. FluMist is currently approved for use in people between 5 and 49 years of age, whereas the application for CAIV-T will seek an indication for use in children under 5, he added.