FluMist Immunization Decreased Flu Related Absenteeism One Year After Administration in a School Based Immunization Program in Alachua County, Florida

BACKGROUND: Schools are virus exchange system ultimately spreading the virus to the whole community. Children are “super spreaders”. They shed more virus and do so for longer periods of time than adults. Computer models have suggested that immunizing school children could protect the whole community. This study assessed if there was a decrease in flu related school absenteeism one year after FluMist was administered at a time when the inactivated vaccine was shown to be only 40% effective.

METHODS: 25% (n=5,198) of Alachua County K-8 school children were immunized with FluMist during the fall of 2006. A year later, flu related absenteeism was evaluated for a thirteen week period (January 7th -April 13th,2008). This time frame was determined by the health department as the height of a flu outbreak. Children in grades kindergarten and 10-12 acted as controls for this time period, having not received the vaccine.

RESULTS: Absenteeism of students in grades 1-9 (75.6%), 25% of whom had been immunized, was lower than the control (78.3%), who had not been immunized (P=<.0001).

CONCLUSION: FluMist immunization decreased school absenteeism during a flu outbreak one year after vaccine administration, even though the virus had shifted. Given the apparent boarder protection provided by FluMist, immunizing school children might reduce the severity of the next flu pandemic.