What about a SARS vaccine? Vaccine studies for SARS-CoV-1 were started and tested in animal models. An inactivated whole virus was used in ferrets, nonhuman primates and mice. All of the vaccines resulted in protective immunity, but there were complications; the vaccines resulted in an immune disease in animals. No human studies were done, nor were the vaccine studies taken further because the
virus disappeared. Many factors were involved in the end of SARS-CoV-1, perhaps including summer weather, and certainly strict quarantine of all those who had contact with infected individuals, but
we don't really know why the epidemic ended. Viruses are like that, unpredictable!
Many of the vaccines being developed for SARS-CoV-2 are quite different, and many use only small portions of the virus, or the
virus RNA. This may circumvent the problems with SARS-CoV-1 vaccines that used more of the virus. Vaccine development has a large experimental component; we just have to make educated guesses and try different things and see what works. Hence, many different avenues for vaccines are being tested by different labs around the world.