Abertawe Bro Morgannwg University Health Board will offer MMR vaccines at drop-in clinics at hospitals in Swansea and Bridgend today.
The clinics will be held in the area's four main hospitals - Singleton and Morriston in Swansea, Neath Port Talbot and the Princess of Wales in Bridgend between 10am and 4pm.
It's after latest figures from Public Health Wales revealed the number of confirmed cases of measles reached 942.
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.