Health chiefs are warning that measles is far from beaten in an area battling an epidemic and protection too low to stop the disease spreading.
A programme to vaccinate thousands of people.. across the greater Swansea area has been hailed a success.
Despite this, Public Health Wales warns it is wrong to say the battle against the disease has been won.
"The Gwent area is a particular concern" says Dr Richard Roberts.
"We know that around 10, 000 children have missed the dose of MMR - many of them young teenagers - and they really need to come forward."
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.