The Health Service Executive has warned Irish soccer fans travelling to Euro 2012 that they could be at risk of getting measles.
There has been a major outbreak of the highly infectious disease in Ukraine, one of the host countries.
There are also high rates of measles in other countries playing in the tournament, including France, Germany and Italy.
Dr Brenda Corcoran of the HSE's National Immunisation Office said: "It's everywhere in Europe ... and we know that in mass gatherings of large numbers of people measles can spread very easily.
"Young adults who haven't had their MMR vaccine are at risk and there's something that can be done to prevent them from getting sick.''
She urged people who have not been vaccinated to get the vaccine.
The MMR vaccine is available free from GPs, although there could be an administration fee.
