There is an urgent need for the development of more modern techniques of vaccine production . Dr. Carlos Del Rio : Canada and Mexico have responded well to swine flu outbreak . He says cross - border cooperation is crucial to successful battle against disease . Key question is why Mexico 's cases have been more deadly , he says . Del Rio : Key factor may be presence of pneumonia in those who died .
Dr. Carlos Del Rio : Canada and Mexico have responded well to swine flu outbreak . He says cross - border cooperation is crucial to successful battle against disease . Key question is why Mexico 's cases have been more deadly , he says . Del Rio : Key factor may be presence of pneumonia in those who died .