Perhaps the anti-inflammatory effects of COX-2 inhibitors might conceivably provide some symptomatic relief to fibromyalgia patients, and even have some benefits for disease pathogenesis.
However, from what I have read, it seems that the COX-2 pathways plays an important role in viral replication for a number of viruses.
This study mentions that:
It is particularly telling that rhesus cytomegalovirus actually possesses genes which enable it to make its own fake (homolog) COX-2. This shows that it is very important for this virus to have high levels of COX-2 for its survival.
Another interesting thing which that study found is that inhibition of either COX-1 or COX-2 caused a moderate inhibition of pseudorabies virus growth (25-fold to 30-fold), but when both COX-1 and COX-2 were inhibited simultaneously, either with a nonspecific COX inhibitor or with a combination of specific COX-1 and COX-2 inhibitors, pseudorabies virus yields were
dramatically reduced (greater than a 200,000-fold reduction).
Note that the pseudorabies virus which the researchers studied is similar to herpes simplex.