CHA 1 怎三 1 Soa2=/ 江 1三 1已 1与 1 Hon o "不了 1
21 Epidemic
where do“neW” HA and na come from? 13 types HA 9 types NA all circulate in birds pigs avian and human
22 where do “new” HA and NA come from? • 13 types HA • 9 types NA – all circulate in birds • pigs – avian and human
where do“neW” HA and na come from?
23 where do “new” HA and NA come from?
why do we not have influenza B pandemICS ? so far no shifts have been recorded oQ2o01010e no animal reservoir known
24 why do we not have influenza B pandemics? • so far no shifts have been recorded • no animal reservoir known
Resistence The particles are relative labile, not resistant to drying, etc
25 Resistence • The particles are relative labile ,not resistant to drying, etc