Stephen G. Baum, MD

abstract: The keystone of influenza prevention is still vaccination. The 2 available types of influenza vaccine--the inactivated vaccine, which is administered intramuscularly, and the attenuated vaccine, which is delivered via nasal spray--have efficacy rates of 70% to 80%. Unfortunately, only about 65% of persons who should receive the influenza vaccine are, in fact, vaccinated. The neuraminidase inhibitors oseltamivir and zanamivir are 70% to 90% effective in preventing influenza. These antivirals also are effective in reducing the severity of influenza symptoms and the duration of illness when administered within 48 hours of the onset of clinical disease. Some patients have difficulty in self-administering zanamivir because the inhalation process is fairly complicated. Because of the resistance pattern observed in 2005, amantadine and rimantadine are not currently recommended for prophylaxis or therapy. (J Respir Dis. 2007;28(1):21-29)