Dr Judy Hart, of Public Health Wales, said that since "two-thirds" of the 61 people contacted were born before 1970, they're thought to be safe - since it's likely they were exposed to it during childhood.
Attention has been focused on the younger group.
"Take up of the MMR vaccination did dip because of adverse publicity. There are a group of children in the UK whose parents maybe felt they wanted to wait a while to be sure" said Dr Hart.
"I'd like to encourage them to realise you can have the catch up of missed doses of vaccine at any age"
More top news
Mainly dry with lengthy clear spells overnight and just a few showers likely, especially in the north and west.
Ysgol Uwchradd Caergybi became the UK's first comprehensive 65 years ago. Academies are now dominant in England, but certainly not in Wales.
Dry for most, but a few showers likely.