Gydag ychydig dros draean o'r rhai sy'n gymwys wedi cael eu brechiad atgyfnerthu COVID-19, dywedodd Dr Frank Atherton ei bod yn hanfodol bod y rheini sy'n wynebu'r risg uchaf o salwch dros y gaeaf yn derbyn y gwahoddiad i gael brechlyn COVID neu'r ffliw.
With just over a third of all those eligible having received their COVID-19 booster vaccination, Dr Frank Atherton said it was vital those most at risk of winter illnesses took up the offer of a COVID or flu vaccine when they are invited.