Thanks for posting this, Elver - it makes for very interesting reading. So lifetime exposure to avian viruses could be the reason for elderly men being more susceptible to H7N9 because of pre-existing antibodies working against them? Interesting theory, and it would explain the demographic we've been seeing. I wonder if this will hold true if the virus becomes more efficiently H2H and begins to infect people with less poultry contact who've previously been vaccinated to seasonal flu and H1N1. It hasn't yet made it out of China and Taiwan to populations with limited exposure to live or freshly killed poultry, so it'll be interesting to see if it changes it's behavior should it move into different socio-economic areas like western Europe and the US.

So basically, it isn't specific to the H1N1 vaccine but whether an accumulated exposure to flu viruses poses an increased risk. In theory, repetitive flu vaccinations would do that because you are guaranteed to be exposed to more  than if you just chanced it without. Interesting and I do wonder the same as Jacksdad...what will happen if H7N9 moves into populations that do not have the same exposure to avian influenzas

Reads that way to me.

There was another article Elver posted stating that if you had the actual h1n1 flu you had a type of super immunity to flues. It did not say if the vaccine would cause that these articles now seem to debunk that or maybe all three are speculative.  I recall the great debate over whether or not to take that vaccine, many claimed it was going to set us up for even worse sickness like injecting a ticking time bomb of sorts. Sure hope those conspiracy theorists were not correct back then. Or the most vulnerable will have a rough time, as they gave the vaccine out at first based on certain criteria if you recall, then it was also part of the flu shot the following year.  This will be important info, bc all those vaccinated before should in theory be vaccinated first then. However if taking one vaccine that was supposed to protect them ended up causing more death, I would imagine it may be a hard sell to get people to take yet another. Not good news but a good find, at least those of us who were vaccinated can try to protect ourselves in other ways.