Inactivated COVID-19 vaccines (that is, vaccines using virus copies that have been killed - live vaccines would be ones where the virus has been weakened) have

Inactivated COVID-19 vaccines (that is, vaccines using virus copies that have been killed - live vaccines would be ones where the virus has been weakened) have been a thing for some time. IIRC China used a lot of them. My understanding is that they're not quite as good as mRNA in terms of efficacy (though I haven't looked this up in some time.)