I'd err on the side of caution.
I like ramping sets on a return from illness. Do the first set at 5-10% below your last healthy VD. Ramp up from there. If you feel like complete shit...just stay at that 5-10% reduced load for sets across.
If someone's returning from a really shitty bout of flu (or something as sucky), the initial set might be a 20% drop
Eta: total voodoo alert: I honestly think the physiology of (stress/recovery/adaptation) is different training through (or at the tail end of illness). I've always had huge breakthroughs following illness (if I actually muster the will to lift cautiously through the illness).