There is also research that suggests that getting a regular flu shot may increase the chance of getting H1N1, so it's possible that the interaction between the various flus and vaccines is more complicated than we thought.
Mayhaps or not... via twitter @aetiology (epidemiologist) -- seasonal + H1N1 vaccine: good or bad? New study contradicts unpublished Canadian data: http://bit.ly/6FP2g (sounds like both are preliminary)...