Sorry for the delay in replying to you, I haven't read the board for a while.
I did speak to David about my relapse. Part of his explanation is copied below.
Relapse in the first six months of treatment (and perhaps longer) seems to remain a possibility even where Chlamydia pneumoniae is the prime culprit. This may be because relapse is due to simultaneous local mass cell-death of oligodendrocytes, the cells which make and maintain myelin. There seems to be two immunological components which prompt this sudden cell-death: locally high levels of antibodies to a chlamydial protein, hsp60, and sudden high levels of the host-protein, gamma-interferon. Though the antibiotics prevent the germs from making hsp60, antibodies to it can take months to subside. Any acute viral infection (such as flu) can cause an elevation of gamma-interferon. So a window of vulnerability exists.
As the relapse was triggered by a nasty dose of the flu, the explanation seems valid to me.
In short, and for the moment, I am continuing with the regimen. There aren't any real alternatives for me anyway.
Should I get accepted for the Campath trial then that may change, but that's a decision for another day.