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
19-year-old Charlie Lee was jailed after tricking the grandfather out of nearly £50,000 in a home improvement scam.
Professor Roger Scully looks at what the latest Welsh Barometer poll tells us at the start of the election campaign
Welsh Labour members will meet later today in Ammanford for the launch of the party's general election campaign.