The present invention provides methods for treatment or prophylaxis of viruses, particularly influenza virus, by administration of agents, particularly neutralizing antibodies or active fragments thereof, directly to the respiratory tract, including by intranasal or inhalation administration. The invention provides compositions suitable for intranasal or inhalation treatment and administration. The invention includes methods for treatment or prophylaxis combining intranasal or inhalation administration with intraperitoneal or intravenous administration of antibodies.