Mae byrddau iechyd eisoes wedi cael dros 80,000 o ddosau o'r brechlyn ar gyfer y rhaglen brechu mewn ysgolion erbyn y gwyliau hanner tymor - mae hynny'n ddigon ar gyfer 46% o gyfanswm nifer y plant a frechwyd mewn ysgolion y llynedd. Mae'n bosibl y gall Lloegr barhau â'u rhaglen brechu mewn ysgolion am gyfnod hwy, ond mae hynny oherwydd yn gyfrannol y byddant wedi defnyddio llai o'r stoc a ddyrannwyd yn gyfrannol iddynt ym mis Hydref.
Over 80,000 doses of vaccine had already been received by health boards for the school programme by the half term break – this is sufficient for 46% of the total number of children vaccinated last year in schools. England may be able to carry on with their schools programme for longer, but that is only because they will have used proportionately less of their allocated stock in October.