Bird Flu is just another strain of the influenza virus. The strain commonly referred to as the Bird Flu in the news is the H5N1 strain. Currently this strain of influenza principally infects birds, but it is capable of infecting mammals, but does not spread well from mammal to mammal.
The influenza virus family is characterize by a rapid mutation rate. This is one of the reasons that there is a different influenza vaccine every year, the bug that was going around last year is not the same as the bug that is going around this year.
The strain of the H5N1 virus that is causing so many problems in Southeast Asia is mutating as well. The death rate in bird flocks is decreasing in some areas. While this may sound like a good thing, it means that the chances of the virus spreading from flock to flock is increasing because birds are living longer with the virus and are able to transmit it to other birds for a longer period of time.
The concern that the international medical community has is that the strain could mutate into a form that is readily transmissible from human to human. This is most likely to occur when a human that is infected with a human transmissible flu virus is also exposed to an H5N1 strain. This is most likely to happen in small family farm settings where there is closer contact between the birds and humans.
Once an H5N1 strain of the flu virus becomes readily transmissible between humans we will likely end up with a world wide flu pandemic. The reason is that there has been no human transmissible H5N1 strain for so long that no one has an acquired immunity to the strain. The only way to stop the quick spread of the new human transmissible strain of H5N1 would be to vaccinate a very large portion of the earth’s population. Unfortunately, a good vaccine cannot be developed until the strain becomes transmissible so that we can create the vaccine specifically for that strain. Vaccine production takes six months to a year from the time the strain is identified. By that time a very large number of people will have come down with the bird flu and many will have already died.
There is work on going for a vaccine that will be pretty close to right one. It will not give good protection against the eventual pandemic strain, but it will give some protection. Hopefully, it will be good enough to reduce the number of people that will die. Similarly there are some anti-viral medications that seem to treat the the current incarnation of the H5N1 virus in some of the people that have been infected. Work is on-going to stockpile these drugs so that they will be available in large quantities to treat the hundreds of thousands, maybe millions, of people that will probably be infected by the disease.
All of these pandemic prevention steps are costly. Large portions of the population of the earth will not be able to afford the almost good enough vaccine, nor the anti-viral medications. It is important, though that those people be provided the protections, maybe even before the people who can afford them (the United States, Europe, Japan and South Korea), because it is in those poorer nations that the pandemic will actually start.