WHO moved to re-tagged swine flu as Influenza A(H1N1), IMHO, probably due to several reasons:
1. more of human-human transmission, rather than from the swine. apology to the porcine society.
2. virus cannot be transmitted by eating pork, therefore may unnecessary put the pork industry in jeopardy.
3. it is believed to be a new strain which combined bird, swine and common human influenza, by right should be call bird-swine-human flu (quite a mouthful, i guess)
4. it is rather difficult for a Muslim to be labelled as a swine-flu patient.
Once, people asked me, what's with the H & the N?
Here's the thing.
Virus is a very simple thing. It consist of the shell and the core. The shell is protein encoded by the core, which is the DNA or RNA.
To multiply itself, it will need a living cells, for by itself, virus is not a living thing.
Flu virus labelled as A, B, C as there are difference in its RNA segments and protein coding, and was further differentiated by its H & N.
H is for haemaglutinin. haem-blood, aglutinin-clump together. Haemaglutinin is simply a glycoprotein on influenza virus responsible for binding the virus to the cells that is being infected. So far, at least 16 subtypes of H had been recognized H1 to H16.
Once the virus is in, it will start to multiply and multiply and multiply and multiply until the cells is bloody loaded with viruses and they're ready to break out and chill.
That's where the N comes in.
N is for neuraminidase. neuraminidase is an enzyme on the surface of influenza viruses that enables the virus to be released from the host cell, but cutting one of the structures of the cell membrane.