Health experts in the United Kingdom are warning there is a "very real risk" of a deadly measles outbreak unless vaccination rates improve.
A well-regarded epidemiologist said low rates of vaccination could result in tens of thousands of cases of the virus in London alone.
The Victorian era disease is highly contagious and can lead to severe complications such as meningitis, pneumonia and even death.
Recently released data shows cases are on the rise in the UK with 128 infections reported between January 1 and June 30, compared with just 54 for the whole of 2022. The increase in cases is causing concern, with UK Health Security Agency (UKHSA) saying there is now potential for a major resurgence.
While there have been cases across the country, London is most at risk due to vaccination rates of just 70 percent, well below the 95 percent needed for herd immunity.
The virus can be prevented by the MMR vaccine: it was nearly wiped out entirely in the United Kingdom in the 2010s but a drop in vaccine rates saw its return, with 880 cases reported in 2019.
UKHSA consultant epidemiologist Dr Vanessa Saliba told The Sun it's vital children receive both doses of the MMR vaccine to protect them against the virus.
"Measles can be a serious infection that can lead to complications, especially in young children and those with weakened immune systems. Due to longstanding sub-optimal vaccine uptake, there is now a very real risk of seeing big outbreaks in London," Dr Saliba told the outlet.
"Measles spreads very easily but is preventable. To help protect ourselves, our families and those around us it is vital we all ensure we are vaccinated with two doses of the MMR vaccine, free on the NHS whatever your age."
She told The Sun anyone who has missed out on their MMR vaccines should catch up now.
The United Kingdom isn't the only country concerned about a measles resurgence.
Earlier in the year, a measles case at Auckland's Albany Senior High School sparked fears over a major outbreak due to low immunisation rates.
More than 1000 students and teachers were forced to isolate, and Auckland Regional Public Health Service (ARPHS) ordered the school to close for two days after the infected student attended classes while infectious.
New Zealand is currently at a high risk of a measles outbreak, according to Health NZ.
"Not enough people in New Zealand are immunised against measles, which means it could just take a single case of measles to start an outbreak."
At least 95 percent of people in New Zealand need to be immunised against the disease to prevent an outbreak.
The MMR vaccine is free for all children in New Zealand and all adults born after 1969, if they’re eligible for free healthcare.
