I have little to no faith in a vaccine because (AS I SEE IT) if you look at the flu vaccine, it's great at fighting LAST YEAR'S flu. This thing is mutating and by the time there's a vaccine it won't be nearly as effective against the current strain of C-19. Will be better than nothing, but i think people relying on a vaccine are putting all their eggs in 1 basket. I'll welcome any healthcare provider to set me straight on that though, as i'm not only not an expert, i'm not in the healthcare field.
Drawing any comparisons between the seasonal flu vaccine and the attempts to develop a Covid-19 vaccine is a serious mistake.
Flu is short for influenza. There are multiple subtypes of influenza. Each spring, experts at the CDC (I think other groups are also involved; too lazy to check) meet. They analyze all the data they have on various outbreaks of influenza (mostly in Asia), to determine what configuration should be used for that year's flu vaccine in the USA.
There are 4 subtypes of influenza: A, B, C, and D. Only A- and B-type cause major problems for humans. C-type causes a very minor issue for humans, while D-type does not affect humans; it mostly causes issues for cattle.
A-type is the one that causes the biggest problems for humans. Scientists look at two proteins on the surface of the virus -- hemagglutinin (H) and neuraminidase (N). There are 18 different H subtypes (H1 through H18) and 11 different N subtypes (N1 through N11). If you do the calculations, you can see that there are theoretically 198 different influenza A subtype combinations of the different proteins. So far, only @ 130 have been identified in nature, but there is always a fear that a mutation will occur and a new combo will take place.
Keep in mind, there does not exist a flu vaccine that you take one time, and it affords you immunity from the flu for the rest of your life. That's because of all the aforementioned different types of permutations The experts, to the best of their ability, configure the vaccine to what they see is occurring in various hot spots. Most years, they get it right. Some years, they get it wrong, so to speak, and what they have configured does not really afford a lot of protection against the type of combination that is present in flu season. (There is, I believe, a universal flu vaccine that is in Phase II testing. If it's successful (hardly a given) it would replace the seasonal flu vaccine and you would likely only have to take it one time and be protected against all types of influenza.)
The COVID-19 virus is a coronavirus. As such, it doesn't really behave like the influenza (which is not a coronavirus). Many of the vaccine candidates in the pipeline are based on work that was done in the past decade on the MERS and the SARS viruses, which are also coronaviruses.
The weakness (so to speak) of the COVID-19 coronavirus is that it has one protein on its surface. While there have been some mutations of COVID-19, they also exhibit that same protein. Several of the current vaccine candidates are arrayed against that protein. At this point, it's not clear what is the most effective means of fighting that protein. There are multiple possibilities, and the testing will figure out which one is the most effective AND does not cause any harm to humans. (Or, some of the other vaccine candidates, which don't focus on that protein, will prove to be the most effective.)
I tried to simplify the scientific aspect of this as much as I could. Hopefully, I presented it in a way that makes sense to a non-scientist.
I'd also add that nobody in science is putting all their baskets, so to speak, in a vaccine. Independent labs and pharma companies around the globe are working frantically to come up with effective treatments for Covid-19. They are all aware that the fastest a vaccine has ever been developed, from concept to approval, is four years. With all the focus on Covid-19, there is hope that this timeframe can be reduced for a vaccine. Those working on effective treatments are trying to come up with something that can work until a vaccine is available, and also realize that due to the challenges of developing a vaccine, an effective treatment may be the best bet we have for quite some time.