The majority of measles cases in Europe occur in the unvaccinated with kids under two the most at risk of dying, new research reveals.
One-year-olds who contracted measles were six times more likely to die from the highly contagious virus, according to data gathered from an EU study.
The findings were revealed as a major outbreak of the disease sweeps through Europe.
There has been a sharp increase in cases in the UK after unvaccinated holidaymakers returned from Europe
Public Health England has urged people to protect themselves from the viral illness after more than 250 cases were reported since the start of the year.
And with a further 90 laboratory tests are under way, that number may well rise.
Unvaccinated at risk
The majority of reported measles cases in Europe (81 per cent) were found to have occurred in non-vaccinated patients.
In the study 37,365 measles cases reported to the European Centre for Disease Prevention and Control (ECDC) from 1 January 2013 through 31 December 2017 were examined.
Most cases, 81 per cent, involved children who were two or older.
Of the remaining 19 per cent, nine per cent were one-year-old and 10 per cent younger than 12 months.
The study found that a third of the patients analysed were hospitalised and 11 per cent suffered from pneumonia.
Most cases were in Italy, Romania, Germany, the Netherlands and the United Kingdom, with each country reporting more than five per cent of the cases.
Presenting author Dr Emmanuel Robesyn of the European Centre for Disease Prevention and Control (ECDC) in Stockholm said the analysed data was intended to support European states in reaching the recommended 95 per cent two-dose vaccination coverage.
The two-dose measles, mumps and rubella (MMR) vaccine was introduced into the UK in 1988. The first dose is usually given to a child within a month of their first birthday.
The second injection is given before starting school, usually at three of four years old.
Children can get the MMR vaccine from six months if they have been exposed to the virus.
The ECDC also set out to determine any possible differences between the youngest and older patients when infected with the disease.
Analysis showed that one in 1,000 measles patients died, and of those, the greatest fatality was seen in the youngest cases.
Cases in one-year-olds were six times more likely to die compared with cases of patients who were two years old or older and infants younger than 12 months were seven times more likely to die.
The World Health Organization has set goals for the elimination of measles and rubella in five WHO regions by 2020 by maintaining high-rates of immunisation.
The new research was presented at the 28th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Madrid, Spain.
The European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) is the annual meeting of the European Society of Clinical Microbiology and Infectious Diseases.