Press for the effectiveness of vaccine doses and the time periods after which additional doses would be needed to provide protection in the context of international travel to be kept under review.
Pwyso am i effeithiolrwydd dosau brechlynnau, a’r cyfnodau amser pan fyddai angen dosau ychwanegol i ddarparu amddiffyniad yng nghyd-destun teithio rhyngwladol, barhau i gael eu hadolygu’n rheolaidd.