why can people who have taken tamiflu not take part in the H1N1 trials?

[dikkertjedap]

???

You can't take part in the trial if you have had swine flu that's why. Nothing sinister.

Thanks - But what if it was given preventatively?

Doesn't matter, it could be residual in your body still and effect the results and if you've been exposed to swine flu you may already have antibodies. Ideally they want people who haven't been infected.

Funnily enough we received our invites recently as well.

Yes - antiviral prophylaxis is against the disease but you could still have been sub-clinically infected.

One of the things about the one-dose trials in the UK and US is that a significant proportion of volunteers had pre-existing antibodies to swine flu.