They all went through at least phase III, even Russia's Sputnik vaccine (even though they announced it as a success before they had their phase III completed).
The Merck/Pasteur vaccine was abandoned after stage 1. The Sanofi vaccine had poor stage 1 results, but they seem to be indicating that they plan to continue development with a much later projected laucnh date. I don't know if that is because they mean they're trying a different candidate entirely or if they're making changes to the failed one.
Well, yes, my assumption was that he was asking about the vaccines that are currently in use. The fraction of drugs/treatments, broadly speaking, that make it past stage 3, is <1%.
Not sure why the downvotes, it's a legitimate question. So there's a phase to see if there are huge side-effects in humans, then a phase to see what dosage to use for effectiveness, then a larger (tens of thousands) phase to get enough data to justify using it on millions of people. I think there are normally more phases after that when you're not in a pandemic.
