At that time scientists knew that antibodies from people infected by the 1968 pandemic virus also reacted with an influenza strain isolated in 1963 from flu-ridden ducks.

• 那时科学家已经知道，来自1968年流感患者体内的抗体，同时可作用于1963年从带有流感病毒的鸭子体内所分离出来的病毒株。