Lots of variables in that, but unlikely we'll get enough people vaccinated by end of year for that to be the reason we're able to get back to football (not saying we won't get back to football, but vaccine in 6months likely won't be the reason):
- September is the absolute earliest you're going to get phase 3 data from Moderna (most advanced US program). More likely it'll be end of year/early next year, but there's a possibility politics will play into it and Trump administration will push to have early data published pre-election. Assuming that early data is good enough for approval (risky - but this whole process has been risky), then the earliest you have distribution is October.
- Problem is manufacturing capacity (and the potential politics around it). Moderna has said they'll be able to do 500M doses annually...eventually (and you need 2 doses/person 1 month apart, so capacity for 250M people). Likely won't be there right away and there's questions on how it'll be allocated by country (does US take all initial capacity for itself? share with others assuming it's first or one of the first?). I'm guessing they won't have that capacity until early 2021. That means whatever capacity they do have will be allocated to high risk people (elderly, healthcare workers, etc.)
- There are other programs that are not too far behind (J&J, AstraZeneca, etc.) that'll help with capacity, but also unlikely to have meaningful impact by end of 2020
Of course, the above all assumes that the vaccines work. We only have phase 1 data from Moderna, and it's just antibody data. The FDA has said antibody levels are not sufficient to prove a vaccine works. There's been several examples of vaccines where antibody data looked good but actually immunity wasn't good (RSV, and i believe SARS is the other one). I'd google Ken Frazier's comments (Merck CEO) if you want to learn more about that. It's promising, but we're still in the 3rd inning of this game, and Moderna's platform has never had an approved product and was only tested on 45 people.