Inhaled Zanamivir for the Prevention of Influenza in Families

Influenzaviruses are frequently transmitted within households. In some epidemics, up to 50 percent of households have one or more members who become infected. The average secondary attack rates among family members is 25 percent, 1 although family composition, the circulating viral strain, and the presence or absence of exposure outside the household 2 influence the likelihood of secondary cases. Amantadine and rimantadine selectively inhibit the ion-channel function of the M2 protein of influenza A viruses. 3 These drugs have been used for postexposure prophylaxis in households, with reductions in influenza among family members (household contacts) of the index patient ranging from 3 to . . .