> 1) Did that 1957-58 vaccine use existing tech? My understanding is that other RNA vaccines and therapies were already under FDA trials with ~10 year time-fram

> 1) Did that 1957-58 vaccine use existing tech? My understanding is that other RNA vaccines and therapies were already under FDA trials with ~10 year time-frames since the method is new. Our scientific knowledge in 1957 was limited at best. The double-helix was discovered just a half-decade before. Today, we understand in-depth most of the mechanisms of action involved. There just isn't a comparison here. The COVID19 vaccine is far safer than what we put together in 1957, no question. > 2) Why is sequential better, because it is considered safer? It's safer to the original research subjects, but not to the general public. For general safety, you don't find out more by going slowly. You generally learn strictly more from a human study than an animal one, and you learn more from a large study than from a small one. The point of an animal study before first-in-man is to not endanger a human subject. Small groups come before big ones to pick off things which might e.g. harm 10% of subjects. And so on. The decision was made to skip that step, slightly raising the risk of the subjects, in order to save millions of lives. Part of that is we had pretty darned good reason to believe the vaccine was safe, and part of that was the grave risk. > 3) Yes, short-term we know it is extremely safe. But there are zero people that have had the vaccine much over 1 year. Long-term effects are unlikely but it's just not scientifically correct to say that this vaccine is better studied than any other just because of the number of doses administered. Duration matters a lot. Not so much: - We have historical evidence. Do you know of any vaccine in the history of mankind which had long-term effects not visible the first few months? I don't. - We understand mechanisms of action pretty well at this point. Your body gets all sorts of junk thrown at it all the time -- random polens, plastics from your water bottle, randomly mutating cold viruses, and so on. There just isn't any reason to believe a new vaccine is any more dangerous than a random bug bite. Indeed, we understand the stuff going into the vaccine a lot better than we do a random bug.