More than 120 cases of measles have now been confirmed in outbreaks affecting five areas of England.
Public Health England (PHE) said the current cases are linked to “ongoing large outbreaks” in Europe.
The most recent updates show that, as of January 9, West Yorkshire had 34 confirmed cases, Cheshire and Liverpool had 29, there were 32 in the West Midlands, 20 in Surrey and seven in Greater Manchester.
The Measles virus (Cynthia Goldsmith/Centers for Disease Control and Prevention/PA Images)
The health body previously warned that those who recently travelled or were going to travel to Romania, Italy and Germany without receiving two doses of the MMR vaccine are particularly at risk.
Measles is a highly infectious viral disease which typically lasts up to 10 days and begins with cold-like symptoms and a measles rash. It can lead to serious complications, including pneumonia.
PHE said the overall risk of measles is low among the population, as the UK achieved World Health Organisation (WHO) elimination status in 2016, alongside Denmark and Spain.
This means the number of cases in the UK across a period of at least three years was low enough to prevent the disease spreading among the general population.
The MMR vaccine is a combined inoculation which protects against measles, mumps and rubella and is available to all adults and children who have not completed the course.
The full course requires two doses and anyone who is unsure of their vaccination status is encouraged to check with their GP.
Dr Mary Ramsay, head of immunisation at PHE, said: “This serves as an important reminder for parents to take up the offer of MMR vaccination for their children at one year of age and as a pre-school booster at three years and four months of age.
“Children and young adults who missed out on their MMR vaccine in the past or are unsure if they had two doses should contact their GP practice to catch up.
“We’d also encourage people to ensure they are up to date with their MMR vaccine before travelling to countries with ongoing measles outbreaks.”
She added: “The UK recently achieved WHO measles elimination status and so the overall risk of measles to the UK population is low, however due to ongoing measles outbreaks in Europe, we will continue to see cases in unimmunised individuals and limited onward spread can occur in communities with low MMR coverage and in age groups with very close mixing.”
PHE said local health protection teams were working with councils and the NHS to raise awareness among communities and health professionals.
The NHS advises anyone who suspects they, or their child, might have measles to contact their GP.