Two things can be true;

1. There is a virus that escaped a lab (There is ample evidence supporting this hypothesis). The virus had a very low mortality rate, but could affect certain risk groups. As the virus evolved, it became much less virulent, and (unvaccinated) people built up immune protection from it.

2. The "vaccines" contains a novel mRNA technology with lipid nanoparticles that spreads into your every vessel and organ. They contain a sequence which tells your body to create a toxic spike protein (modelled after the surface spike on the original Wuhan virus), which the immune system then targets for elimination. This spike is not easily degraded, it lingers on for months to years and causes a lot of systemic disease. We don't know if there is an off-button for the vaccinated.