Over 600 measles vaccinations were carried out over three sites within just one hour of the clinics opening this morning, according to a spokesperson for Aneurin Bevan Health Board.
The clinics are being held at locations across south and west Wales today as the measles outbreak continues.
The number of confirmed cases now stands at over 800.
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.