At hynny, mae’r JCVI yn cynghori, yn amodol ar ystyriaeth briodol gan y timau a fydd yn rhoi’r brechiadau o ba mor ymarferol fydd gwneud hynny, y dylid, fel mesur eilradd, cynnig ail ddos o'r brechlyn COVID-19 Pfizer-BioNTech o leiaf 12 wythnos wedi’r dos cyntaf i bob plentyn a pherson ifanc rhwng 12 a 15 oed. Gellir lleihau'r bwlch ar gyfer y grŵp hwn (a phobl ifanc 16-17 oed) i o leiaf 8 wythnos rhwng dosau os bydd y data epidemiolegol sy'n dod i’r amlwg yn cefnogi hyn.
In addition, JCVI advises, as a secondary measure, that subject to appropriate consideration by deployment teams regarding feasibility, all children and young people aged 12 to 15 years should be offered a second dose of the Pfizer-BioNTech COVID-19 vaccine at a minimum of 12 weeks from the first dose. The interval for this group (and 16-17s) may be reduced to at least 8 weeks between doses if supported by the emerging epidemiological data.