Dim ond ar ddiwedd yr haf neu ddechrau'r hydref y bydd y rhan fwyaf o oedolion iau wedi cael eu hail ddos o frechlyn COVID-19 a bydd ganddynt lefel uchel o amddiffyniad o hyd. Bydd manteision cynnig brechiadau atgyfnerthu i’r grŵp hwn yn cael eu hystyried pan ddaw rhagor o wybodaeth i law.
Most younger adults will only have received their second COVID-19 vaccine dose in late summer or early autumn and they will still have a high level of protection. The benefits of booster vaccination in this group will be considered when more information becomes available.