If you're interested in a readable explainer about the SARS2 vaccines in development, here is a "Tweetorial".
I've been following the programs very closely, and this immunologist is describing the clinical data accurately. He has a much more detailed Nature article as well, linked in the Tweet.
https://twitter.com/florian_krammer/status/1310372301314101250
I expect that in about 4-6 months, most of us will start having the opportunity to get vaccinated. Clinical trial failure remains possible, but I think odds are that some (enough) of these programs succeed.