It is likely that those in priority groups 1 to 4 and possibly cohorts 1 to 9 or wider will need a single dose of COVID-19 vaccine as a booster vaccinations.
Mae'n debygol y bydd ar y rhai yng ngrwpiau blaenoriaeth 1 hyd 4, ac o bosibl grwpiau 1 hyd 9 neu’n ehangach, angen un dos o frechlyn COVID-19 fel brechiad atgyfnerthu.