That’s what Sinovac and Sinopharm are, but the have reportedly very low efficacy.
It takes a long time to develop an inactivated virus vaccine because you have to culture a lot of live virus, first for development and testing and then for production.
Also, you can’t just inject dead virus, the immune system will ignore it because it’s dead so you have to find an adjuvant that will work to make the immune system sit up and take notice. That bit can take a lot of testing of various combinations and strengths and probably why the rushed Chinese vaxxes are pretty worthless.
Novavax is producing a subunit vaccine which uses purified pathogen pieces but it’s not available yet, still processing its EUA application.
Interesting. Thank you.