I just wanted to add another response here, after thinking about it for a few days. I’ve read a papers where killed HIV vaccines etc seem promising. So, I think this is a viable strategy, but there are a few issues. As I wrote in my other comment, you are probably mainly stimulating an antibody response, but not a cellular response.
The issue with using UV, it probably a higher chance of viral re-activation. You would probably use gamma irradiation, maybe with heat and chemical treatment also. The issue with inaction is that you potentially alter the antigens.
The other issue is that RNA viruses mutate quite fast. So, you may get vaccine escape variants. This is more so an issue if vaccine distribution takes many months to roll out. Whilst at the same time the virus is circulating in the population. You may end up vaccinating everyone against one strain but not others. I am unsure but perhaps some mutation that occurs during a live attenuated vaccine may help ward against this.
P.S. in the literature, it does seem (at first glance) that killed vaccines require more doses compared to live vaccines.