The level of immunity in Ireland 'isn't enough' to stop measles outbreaks if we were to get an influx of cases, the HSE has warned.
The health service is beginning its measles catch-up programme from today.
Five cases have been confirmed here so far this year while outbreaks have been reported across Europe.
It is estimated around 10% to 20% of the population are not vaccinated against measles and this catch up programme is targeting them.
It is aimed particularly at children and those in their 20s along with underserved groups like migrants.
The HSE says people who have two doses do not need more top-ups but anyone who does not have two or is unsure if they have any should get both jabs.
Babies cannot get the vaccine until they're 12-months-old but the HSE says they would have natural immunity if their mother was vaccinated.
Director of the National Immunisation Office Dr Lucy Jessop told The Pat Kenny Show they are concerned about people travelling.
"In Ireland thankfully we've only had five cases so far reported this year," she said.
"But we do know that there are large outbreaks ongoing in the UK - particularly around Birmingham - there are outbreaks in other countries like Romania and Cyprus.
"We are concerned that the level of immunity in Ireland isn't enough to stop outbreaks if we were to have a lot of cases coming in to Ireland.
"That's why we are now offering free MMR vaccines to those people who have missed out so that they can catch up and make sure they're immune to measles".
A person getting a vaccine shot, 6-9-18. Image: Tero Vesalainen / AlamyDr Jessop said complications from measles can be fatal in some cases.
"It's an extremely infectious virus, one of the most infectious viruses that we have," she said.
"You can become quite unwell with a high fever, cough, a high temperature - but then it's really the complications that we're particularly worried about.
"At least one-in-five people will be admitted to hospital, you can get lung infections from measles and also brain infections; there's encephalitis.
"Sadly one or two people will die for every 1,000 cases, so it can be fatal - not just for babies and young children but also for adults, particularly someone who may be immunocompromised would be more at risk".
Dr Jessop said there can be some small side effects from the vaccine but they don't last long.
"All vaccines have small amounts of side effect but they are short-lived," she said.
"For example sore arms, and then some people several days after getting the vaccine may get a small rash as well," she added.
Anyone who believes they may the symptoms of or been exposed to the measles virus should phone ahead before attending for a vaccine.
The first symptoms of measles are:
- cold-like symptoms such as aches and pains, a runny nose, sneezing and a cough
- sore, red eyes that may be sensitive to light
- a temperature of 38 degrees Celsius or above (fever)
- small grey-white spots in your mouth
- loss of appetite
- tiredness, irritability and a general lack of energy
Additional reporting: Stephanie Rohan
