UK set to lose measles elimination status after surge in cases
Global measles cases have almost doubled in a year, with the UK likely to lose its hard-won status of having eliminated the disease if it fails to maintain a high-enough vaccination rate, warn researchers.
They highlighted that measles outbreaks were still occurring, and in some cases increasing, even among high-income countries such as the UK, which has previously been verified as measles-free.
“The measles virus is extremely infectious and any gaps in immunisation coverage are potential risk for outbreak”
Patrick O’Connor
The warning was issued by World Health Organization (WHO) researchers at the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Global Congress in Barcelona this week.
Dr Patrick O’Connor, from WHO headquarters in Geneva, gave an overview of the global measles situation at the conference.
He told delegates that the total cases so far for 2024 looked to be on track to at least match the 321,582 cases provisionally reported for 2023.
In 2024, some 94,481 have been reported up to early April, but reporting delays mean the true figure is probably much higher, he noted.
Of these 2024 cases, 42,767 or 45% have been in the WHO European Region. Yemen, Azerbaijan and Kyrgyzstan are the countries with the highest measles incidence in the world.
The UK first eliminated measles in 2016 but re-established transmission – and, therefore, lost its elimination status – in 2018 due to an uncontrolled outbreak that latest more than 12 months.
During the Covid-19 pandemic, the UK was once again reverified as having eliminated measles in 2021, after stopping transmission.
However, it has now seen transmission re-established with UK Health Security Agency data showing 368 cases in England in 2023 and 1,001 so far in 2024 up to 25 April, across various locations.
Dr O’Connor highlighted that the WHO’s European Regional Verification Commission for Measles and Rubella Elimination would review all national measles and rubella 2023 reports on elimination from 10-12 September 2024.
“So, there is a high probability that UK could lose its measles elimination verification status again,” he said.
“The situation in the UK illustrates that achieving and maintaining measles elimination is challenging and needs continuous engagement and response to outbreak and ensuring high routine immunisation coverage.”
UK coverage estimates shows coverage of 90% for 1 dose and 87% for 2 doses of the MMR vaccine, down from 92% and 88%, respectively, in 2017.
While this coverage is relatively high, Dr O’Connor said: “The measles virus is extremely infectious and any gaps in immunisation coverage are potential risk for outbreak. So, coverage needs to high but also uniform and equitable.”
He flagged that the UK was not alone and there had been a worrying surge in the number of countries suffering large or disruptive measles outbreaks – defined as 20 cases per million population continuously over a 12-month period.
“Vaccine hesitancy is only one component that can contribute to lower coverage”
Hanna Nohynek
In contrast, he highlighted the huge amount achieved globally by measles vaccination, with an estimated 57 million deaths avoided globally from 2000 to 2022.
Around 1.5 million of these have been in the European region, where there has been a 98% reduction in annual measles deaths from 3584 in 2000 to 70 in 2022.
He said: “Over the last 20 years, there has been significant progress toward achieving measles and rubella elimination – in order to solidify and maintain those gains, we need to ensure high, uniform and equitable routine immunisation coverage; and robust outreach and rapid outbreak response.”
Also speaking at the event was Professor Hanna Nohynek, from the Finnish Institute for Health and Welfare in Helsinki.
She said: “During the Covid-19 pandemic with closure of the society and limiting the number of human contacts, the transmission of all airborne viruses was reduced, including measles.
“During the pandemic, many children remained unvaccinated, and catch-up vaccinations have not reached them,” she said. “Therefore, we now see cases increasing again in various regions of the world.”
Professor Nohynek added: “Countries should use measles cases and outbreaks as a tracer to identify weaknesses in immunisation programs, and to guide programmatic planning in identifying and addressing these weaknesses.
“Vaccine hesitancy is only one component that can contribute to lower coverage – misinformation about vaccines, access to immunisation services, and on-time vaccination cause immunisation gaps,” she noted.
