both the Moderna and Pfizer-BioNTech vaccines should be used with equal preference in the COVID-19 booster programme.
ni ddylid gwahaniaethu rhwng y brechlynnau Moderna a Pfizer-BioNTech wrth ddewis pa un i’w ddefnyddio fel rhan o’r rhaglen brechiadau atgyfnerthu COVID-19.