That's not talked about much, is it? I heard one medical expert say that -- once -- earlier on and since then, nada. The whole process of developing a vaccine, as I understand it, needs to be developed and not just "make a vaccine". Mice for testing, cultivating the virus, understanding side-effects and risks, screening methods and procedures and so on aren't the same as the process of influenza vaccines. So, yes, a year is ridiculously short and Trump idiotically insists that it's just a few months. As a result, people in charge tell him and everybody else "a year or year and a half" because that's the minimum time if we got lucky at the start to identify a vaccine, all tests go swimmingly well and making billions of doses of the vaccine is not difficult. Because the baby in chief can't accept anything else.
One person was quoted as saying yesterday, this virus will be "stalking humanity" for some time and requires invention rather than using a known technology. The schedule is event driven and not based on time. It could take a year and a half (not likely) or it take decades (also not likely).