WHO provisional recommendation on influenza A(H7N9) vaccine virus

Overview

Since the novel A(H7N9) virus seems to be able to transmit from animals to humans more readily than avian A(H5N1) influenza viruses, and little or no immunity against the novel virus exists in the human population, WHO is actively working with its Member States and partners on effective responses and preparedness. As part of these activities, candidate vaccine viruses have been developed and made available by the WHO GISRS.