Cardiff and Vale University Health Board says it has emerged, after last weekend's clinics at Cardiff Royal Infirmary and University Hospital Llandough, that many parents "are still not recognising the implications" for older children.
It is not planning to hold any more weekend clinics, saying "they are not the most effective way of targeting the children and young people most at risk".
Our aim is to prevent the outbreak coming to Cardiff and the Vale of Glamorgan so we need to focus our attention and resources on vaccinating those children and young people who missed vaccination as part of the routine childhood immunisation programme.
Many of children and young people in the 10-19 year-old age group are still not protected against measles.
This is why we are targeting our resources on those activities we believe will deliver the most beneficial results, rather than delivering further open access clinics.
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.