Yes, the Pfizer vaccine will be the first to receive FDA approval but mRNA therapies/vaccines have been under development since the 90’s. Another interesting read. Note this was published in 2018, precovid.I'll add to this that Pfizer and Moderna vaccines are the 1st mRNA vaccines ever, and the long term effects of such vaccines had never been studied. The AstraZeneca and the Russian Sputnik-V vaccines are adenovirus vector vaccines, a much better-studied type.
https://www.nature.com/articles/nrd.2017.243
The effectiveness of some traditional vaccines, as we all know, can be less than ideal. The target set by the FDA for covid vaccines was 50 percent. Both mRNA vaccines blow that number apart at 95%. GSK/Sanofi just announced a delay in their vaccine development when their trials showed a lack of immune response.
It may come down to whichever vaccine an individual has access to, at least initially.