Those are great questions. However, the Republican party made it so companies can fire employees for any reason. Any reason. Including not getting a vaccine.
When you prioritize the business over the worker, you get decisions like this. A vaccinated worker is far far less likely to get sick. And won't spread the virus to others. It's a simple business decision.
Reap what you sow.
Also, the vaccine is safe. Here's a medical study based on the medical records of 800,000 people. Not self-reporting. Their tracked records. The heart inflammation? 2 per 100,000. https://www.nejm.org/doi/10.1056/NEJMoa2110475