And please don’t say WHEN it comes out as there may never be one IF it comes out would be more appropriate. Unfortunately a lot of people including the government are taking modern medicine/science for granted and assume there will be a vaccine
The corollary of this is "don't say when IT comes out". There could be many different vaccines.
There are hundreds of different vaccines in development. There are different dosing protocols, different strains of the virus, and differences in the human population.
There will be a balance to strike between mild symptoms for lots of people to save severe symptoms for a few. Some vaccines may be expensive to produce or only available in small quantities. Some might need repeated doses.
To pass a phase III clinical trial, a vaccine needs to work better than a control vaccine. It doesn't mean that it is perfect.