If your reason for not being able to receive a dose of COVID-19 vaccine fits one of the 4 “Not Medically Appropriate” reasons, you can apply for a ‘Blanket Waiver.
If the reason is based on religion or moral convictions, it does not fall under the Blanket Waiver category but you can file an individual exemption request to USCIS if you are opposed to all vaccines; not just Covid 19. You must have refused to be vaccinated for all vaccines.