In birds, the virus replicates primarily in the intestinal tract, whereas in mammals, it replicates primarily in the respiratory tract.At the time I was making the argument that nobody had any clue concerning the probablities concerning mutations necessary to get the one to aerosolize into the other form.
Concerning HIV & influenza "superinfection" there are even greater unknowns with respect to probablities.
That notwithstanding, I believe that MA's concern with regards NA prophalaxis of the clinically immunodepressed may warrant concern.
If a mutagenically active influenza virion - trans species and high degree airborn transmisivity vector - arises akin to canine parvo-virus, circa early 1970's, we're in a world of hurt. That being said: I'm skeptical that's going to have anything to do with fusion of HIV & influenza virion.
My greatest concern is that a confluent and virulent strain of avian & human influenza arises having symptoms akin to canine parvo-virus, albeit pneumo-thoracic hermoraghic.
Even at mere 20% fatality that will be a complete and total nightmare.