It has also recommended pregnant women should continue to be vaccinated in September, if delaying until October would mean they risk missing out on vaccination.
Mae wedi argymell hefyd y dylid parhau i frechu menywod beichiog ym mis Medi, os bydd oedi tan fis Hydref yn golygu y byddant mewn perygl o golli'r cyfle i gael eu brechu.