Avian influenza A(H9N2) virus in poultry worker, Pakistan, 2015
Avian influenza A(H9N2) virus isolated from a poultry worker in Pakistan in 2015 was closely related to viruses detected in poultry farms. Observed mutations in the hemagglutinin related to receptor-binding affinity and antigenicity could affect cross-reactivity with prepandemic H9N2 vaccine strains.