Probably a bit but not too much. You need to be totally sure that the vaccine is safe, it does not make things worse, and it actually works. Imagine vaccinating the population and ending the suppression stage, to only find out that the vaccine does not work.
Apparently, the only way to know this for sure is testing, testing, and testing. Start with a few people (while animal testing is going in parallel), then do a few dozens of people, then do for thousands of people (while vaccinating as many people with placebo vaccines to see the difference). Then wait. And then wait more. And then start mass-producing it, giving it first to people who are in high-risk categories (or in case of US, those that have top insurances).
All the researchers are saying that 12-18 months is actually a miracle. It typically takes 10-20 years.