Found this:
Ramsey and Higbee were placed on the reserve/COVID list after testing positive. That knocked them out of Monday night's game and made them questionable for the Rams' Week 15 tilt with the Seahawks.
If Ramsey and Higbee are vaccinated, then they will have to be asymptomatic and test negative for COVID twice no less than 24 hours apart to be eligible to play against Seattle. If they are unvaccinated, then they will be ineligible to play.
It appears Higbee's test may have been a false positive as he had two negative tests following his initial positive test. If his PCR test comes back negative, then he can return to the team Tuesday.