Second doses, which are important for longer term protection, are also beginning to be rolled out with almost 70,000 people having had theirs already.
Mae’r ail ddosau, sy’n bwysig i sicrhau diogelwch hirdymor yn erbyn y feirws, hefyd yn cael eu cyflwyno ac mae mwy na 70,000 o bobl eisoes wedi cael eu hail ddos.