Is there any evidence of medicine is stagnating?

I don't believe I'd agree with that. Medicine makes constant, relentless progress, but it doesn't do so evenly across the board. Yes, Polio was the big killer in the 1950s, and it was solved with an effective vaccine. But look at the progress made in treatment of heart disease. In the 50s, heart disease was simply a killer. You brought in a heart attack patient, put them on bedrest, and they either lived or they died. Today, interventional cardiology is doing absolutely amazing things at fixing diseased or damaged hearts. What used to be a sure death sentence, or something that you leave you as a cardiac cripple, is today often nothing more than a couple of hours in the cath lab, and you go home the next day, good as new. We didn't have CAT scans or MRI machines in the 50s, but look at the progress in diagnosis and treatment they have enabled. Cancer is not one single disease, but hundreds of different diseases, yet every now and then a complete cure is found for one of them. AIDS has been reduced from a lethal and fast killer to more of a chronic condition. Tuberculosis was all but wiped out with the discovery of Streptomycin (but it's returning today). Many parasites that were previously untreatable are today quite easily treatable, relieving a lot of suffering in tropical countries. Schistosomiasis comes to mind; it used to require very complicated filtration of the bloodstream to remove the parasites; today a couple of doses of Praziquantl and the person is quickly cured. The list goes on and on. Eye surgery and prosthetic lens implants. Hearing implants. New treatments for burns. It goes on and on. And all of those things have come about in the past 20, 30, 40 years. I'm sure 40 years from now they'll be curing things that are completely untreatable today. The BIG advances will be in genetic engineering. Lots of good things to come from that field.