True statement about influenza A is -
The viral or antigen is composed of at least two coded proteins hemagglutinins and neuraminidase. Both are strain-specific and is capable of great variation. REF:ANANTHANARAYAN AND PANIKER'S TEXTBOOK OF MICROBIOLOGY 9TH EDITION PAGE NO-498
It has a double stranded segmented RNA
Pandemic are caused by antigenic drift
Nucelocapsid antibody is not specific
Hemagglutinin and Neuraminidase is strain specific
Virology