More than 3,000 people in Merthyr and Rhondda Cynon Taf were given the MMR vaccine in an attempt to stem the spread of measles.
But Public Health Wales says it's still concerned that only half of these were given to people aged between 10 and 18 - the group hardest hit by the outbreak.
Figures today revealed there have been a total of 1,292 cases reported across Wales since the beginning of November 2012.
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.