The CDC recommends routine annual influenza vaccination for all persons 6 months of age and older. When vaccine supply is limited, vaccination efforts should focus on those groups with health conditions associated with increased risk of influenza complications [40••] . Antiviral drugs should not be used as a substitute for influenza vaccination. Their adjunctive use is appropriate in certain targeted populations at high risk for complications of influenza who are close contacts with suspected or confirmed cases [ Table 1 ]. Postexposure prophylaxis should only be used when antivirals can be started within 48 h of the most recent exposure. Recommended duration is 7 days after exposure, and the CDC recommends a minimum of 2 weeks for control of influenza outbreaks in long-term care facilities (i.e., nursing homes with elderly) and hospitals [70••] . The choice to offer post-exposure prophylaxis to otherwise healthy unvaccinated adults should be weighed against the risk of promoting antiviral drug resistance [41••, 1••].