Are there any traditional (attenuated) COVID vaccines in the works? What is their status?

[Ocelot II]

6. A traditional vaccine would actually be less safe than the mRNA vaccines

because traditional vaccines use killed or weakened viruses; in other words, the virus' DNA is injected into you, which forces your body to develop an immune response. mRNA vaccines, however, don't use any viral DNA at all. They are the product of years of research on CRISPR sequences, which can be spliced into a cell's messenger RNA, which creates various proteins. The mRNA vaccines specifically target the spikes on the virus that it uses to invade cells with, so your body recognizes the proteins that make those spikes and develops immune responses to just that material. No viral DNA, which could make more viruses, is used.