The five schools with the highest numbers of unvaccinated or under-vaccinated pupils are being visited by vaccination nurses between tomorrow and Friday.
Letters will be distributed to parents of children who are believed to need MMR vaccinations, to ask for their consent.
Abertawe Bro Morgannwg University Health Board is again holding drop-in clinics at hospitals this Saturday, for a third weekend running.
Aneurin Bevan Health Board has confirmed it will hold clinics for a second consecutive Saturday, in Newport, Abergavenny and Ystrad Mynach.
2013 is expected to be the worst year for measles in the UK for the past two decades. Read more about the illness and how it is treated.
If the Government's top adviser on immunisation thinks the risk of an emergency in England is a possibility, I believe him.