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."