London School of Hygiene & Tropical Medicine
Measles In UK – LSHTM Unpacked
Find out the facts about measles in the UK, as we explore common questions and explain how to protect yourself and your loved ones
A recent report shows cases of measles across the World Health Organization’s European Region, which includes the UK, are the highest they’ve been for more than 25 years. At the same time, large outbreaks of measles in the US have led to the first measles deaths there since 2015.
For our new series, LSHTM Unpacked, we talked to experts at the London School of Hygiene & Tropical Medicine (LSHTM) about what makes measles so dangerous, the risk measles poses to children and adults in the UK, and common concerns about measles vaccines and vaccination.
Why is measles so dangerous?
Dr Alexis Robert, an Assistant Professor at LSHTM who studies the transmission of measles in England and Wales, said: “The measles virus is one of the world’s most infectious respiratory pathogens and can cause life-long disability or death. In the absence of vaccination measles can spread very rapidly, and it used to cause hundreds of thousands of cases per year in England. Outbreaks we see today in the UK are much smaller, because most people are protected against measles thanks to the two doses of vaccine they received in childhood.
“Because measles is so infectious, about 95% of the population need to receive a full course of vaccination to mitigate the risk of outbreaks. If coverage is lower, people who catch measles will infect other people who do not have protection from the vaccine or from having had measles previously. Those who are unvaccinated are then the most likely to be severely unwell and to spread the virus to others.
“Studies have estimated that nearly half of childhood deaths from infectious diseases in the UK prior to the introduction of the measles vaccine could have been due to suppressed immune systems caused by previous measles infections.”
Is there a risk of measles in the UK?
Dr Ben Kasstan-Dabush, an Assistant Professor at LSHTM whose research looks to improve vaccination delivery, programmes and engagement in the UK, said: “Vaccination programmes in the UK and globally have been so successful, it can be easy to forget why we still need them, and many people may not have a memory of the consequences of infections like measles. But history tells us that even a small decline in vaccine uptake can have devastating consequences.”
Why is it important to get the MMR (measles, mumps and rubella) vaccine?
Dr Ben Kasstan-Dabush said: “An individual who has recovered from measles will be immune to infection in the future but this should never be considered as a safe alternative to vaccination.
“Measles infections are aggressive and the condition of someone infected with measles can suddenly deteriorate. You risk exposing yourself or your child to suffering a severe and preventable illness than can cause life-long disability or even death.
“Being vaccinated is the best way to protect you, your child, your family and people who aren’t able to get the vaccine, like young babies, from getting sick with measles or spreading it to other people.”
Dr Alexis Robert said: “Measles outbreaks occur when vaccine coverage is low, as it can spread more easily between those who do not have protection. The latest figures show only 85% of under-5s in England have received two doses of MMR, when the WHO target is 95%, so there’s an urgent need to increase vaccine coverage.
“The rise in cases of measles we’re seeing is not due to a decrease in the effectiveness of the vaccine.
“If individuals vaccinated in the 1980s or 1990s had lost all protection (and were “essentially unvaccinated”), then we would expect to see tens of thousands of cases of measles in vaccinated individuals aged 30 to 40 years old, as they would basically have no protection. This isn’t the case, as the outbreaks we’re seeing have mostly affected individuals who are unvaccinated, especially children.
“While it’s also still possible to be infected with measles if you’ve already had the vaccine, it’s rare. If it does happen, the symptoms and lasting effects will be significantly milder.
“Infants whose mothers have been vaccinated are also protected by their mother’s antibodies. While this protection may not be quite as long lasting as from mothers who have survived a measles infection, it will be in addition to the protection given by the high levels of vaccination around them, that wouldn’t have been there before routine immunisation. This protects them until they’re old enough to get vaccinated themselves.
“Analysis of measles data in England has shown that the number and age distribution of cases is in line with a very slow waning of protection from the vaccine: around 0.04% per year, meaning that individuals who gained protection after vaccination will still be 99% protected 20 years after receiving their second dose.”
Is the MMR vaccine safe?
Dr Ben Kasstan-Dabush said: “Vaccines are designed to trigger an immune response against a certain pathogen, without causing the disease itself. ‘Side effects’ are typically a sign that the immune system is being trained to remember that pathogen, to prevent infection in the future. It’s normal to experience general symptoms following MMR vaccination, but these are often milder and much less severe than what you’d experience by catching measles. Your practice nurse will always explain how to care for your child after vaccination and what to do if you’re concerned about a reaction.
“It’s also important to be cautious with vaccine information you see on social media – it may not always be based on scientific evidence and could put you or your child at risk of a serious illness. We learnt from the COVID-19 vaccination programme that misinformation can travel rapidly and can influence people’s decisions. My advice would be to always check with credible sources like the NHS website or to call your GP surgery.”
Dr Alexis Robert said: “The safety of the MMR vaccine and all vaccines in the UK is closely monitored, and it has consistently been proven to be the safest and most effective way to protect yourself and those around you against measles. It provides long-lasting protection and has saved millions of lives since its implementation in routine vaccination.”
Who can get the MMR vaccine in the UK?
Dr Ben Kasstan-Dabush said: “We know that declining coverage is happening amidst an unforgiving cost of living crisis in the UK, characterised by a generational decline in living standards, political austerity and unequal pandemic recovery. There are clear links between deprivation and lower immunisation coverage because uncertainty affects so many aspects of a parent’s life.
“To reverse the decline in vaccine uptake, it’s important that we continue to see immunisation services with sufficient resources to effectively engage communities and ensure capacity.
“Childhood vaccinations are typically delivered through General Practice, and this is an acceptable delivery route for most parents. We must ensure that the universal offer is complemented by tailored engagement and outreach clinics when required, to help ensure that all families and communities have equitable access.”
https://www.lshtm.ac.uk/newsevents/news/2025/measles-uk-lshtm-unpacked