Indeed, Bob, that's one of the points made in the Dutch paper I believe: that the supposed lack of genetic variability could equally well be explained by vaccine-transmission rather than by contamination. Somebody observed somewhere that the Hue paper could turn out to be a massive own goal, for precisely that reason. The vaccine theory seems to have gained massively more credibility recently, with some unexpected voices taking it much more seriously - perhaps it's slowly becoming possible to think the unthinkable?
One point that doesn't compute for me, about this whole genetic variability argument of Hue's, is that it's only based on an analysis of the very small number of isolates that have been found so far, at this very early stage in the understanding of XMRV - mostly in prostate cancer. How can it have the implications claimed, that the small number of XMRV isolates that have been sequenced are so similar, when we have no idea what other variants there may be knocking around as well that just haven't been detected yet because the primers don't match for those variants? Surely the similarity of the sequences isolated could just be a consequence of the testing methods used so far, the samples chosen for full sequencing, or the methods of isolation which might only pick up those particular specific strains? Something along those lines is surely at least a possibility?
And the other thing about it...I get the point that a live virus is expected to vary quite a bit - that's why Alter and Lo's PMLVs were taken as strong confirmation of the WPI - but hold on, weren't they saying back when Lo/Alter was published that (McClure) "let's be clear, this is a different virus" - and so those PMLV-like sequences can't have anything to do with it because they're different (though very, very similar)? So first we're told it can't be right because there's too much variation in the sequences found so far, and then we're told it can't be right because the sequences in one of the strains found are all too similar...sounds like another Catch-22 to me...
Re: Snow Leopard's important point, which is indeed a good point, touching on the co-factors: the reported findings of very high association with chronic lyme and mold sensitive patients are very suggestive to me. They suggest to me that one thing that XMRV is doing is enabling certain types of infections to remain chronic infections. So Lyme disease is well understood, Chronic Lyme isn't accepted though...but the point is that the XMRV is making a Lyme infection have chronic effects. Similarly, fungal infections are well understood, but permanent acquired mold sensitivity is also not accepted...but again the XMRV could be what makes the condition chronic. And the same could apply to certain types of viral infections: with XMRV knocking around, the body can never fully clear them. The potential mechanisms for this to happen seem so obvious and easy to imagine that it rather leaps off the page: if XMRV infects specific types of B or T cells, associated with specific types of antigens, perhaps because those antigens happen to active at the time of XMRV infection, then whenever your body tries to fight that particular type of infection, XMRV comes out to play.
How tedious that we've all been obliged to spend so much of our time and energy digging deep, deep, deep into tedious political arguments about theoretical contamination possibilities, instead of exploring the much more fascinating detail of how XMRV might work, and how it fits in with all the other things we know about this whole spectrum of diseases. I return to a year-old theme: if you tested a whole bunch of different conditions for XMRV through WPI, and checked out which ones were associated, and the detail of which types of patients were infected, then you'd learn an immense amount of clues about what it is and how it works from the overall pattern. Anybody could do that, very cheaply in research terms, by sending their samples to VIPdx (assuming they'd take them under those conditions - and nobody has said they refused to) - yet it's all been left to the WPI, so that they know so much more about the whole thing - the world is basically handing them a monopoly on this science. And you could get to the truth about CFS/XMRV reliably and quickly by methods like that, by challenging VIPdx labs to test your own samples blind, instead of doing your own contaminated studies and concluding that means the WPI are contaminated as well - which blatantly proves nothing and didn't get past anyone! Those who aren't asking the right questions in the right way, do rather suggest that they very much don't want to know the answers...