I had it (took 3 weeks to resolve completely) about 7 weeks after the jab. It was grim but I was sofa-bound rather than bed-bound for the worst part. Whether this was due to any jab benefits, or simply that I've had flu so many times over the years, I don't know. The flu I had in my 20s was the worst, with hallucinations and a real "I'm going to die" feeling. It was never as bad in my 30s and I only had it once in my 40s.