Measles, mumps and rubella (MMR) vaccination rates have a hit a 13-year low and measles cases are rising across England, with an outbreak in the West Midlands threatening to spread.
In response, NHS England launched an MMR catch-up campaign in January 2024, through which GP practices will contact parents of children aged 6–11 years to book appointments for any missed doses of the vaccine. An additional 1 million people aged 11–25 years in London and the West Midlands, where vaccine uptake is particularly low, will also be invited to catch up on missed MMR vaccinations.
Measles elimination — defined by the World Health Organization (WHO) as the absence of circulating measles, in the presence of high vaccine coverage, along with good systems to identify cases of the disease — was briefly achieved by the UK in 2017, but by the following year, viral transmission was re-established.
However, when the COVID-19 pandemic hit in early 2020, social distancing and travel restrictions led to measles cases almost disappearing, with only 2 confirmed cases in England in 2021. But as society returned to pre-pandemic levels of activity, the number of measles cases has slowly begun to increase again (see Figure 1).
There were 1,603 suspected measles cases notified in England and Wales in 2023, up from 735 in 2022 and 360 in 2021, although a substantial number of notified cases are subsequently not microbiologically confirmed to be measles.
Vaccine coverage
Two doses of the MMR vaccine are given as part of the NHS childhood vaccination programme (at around 12 months of age and again at around 3 years 4 months of age), with vaccine effectiveness in preventing measles increasing from 95% after one dose to 96% after two doses, according to a recent Cochrane review.
The WHO has set a target vaccination rate of 95% coverage with two doses, which it says is the level needed to achieve herd immunity, where those who cannot be vaccinated, such as young babies, are protected. Coverage of 95% for the first dose of MMR vaccine at age 5 years was achieved in England in 2017 but rates have been declining since.
In 2022/2023, MMR vaccination rates were at their lowest level since 2010/2011. Low vaccination rates can lead to widespread community transmission as 90% of non-immune contacts of a measles case become infected (see Figure 2).
Anyone of any age can catch up on any missed doses of MMR by contacting their GP surgery.
Regional variation
The number of measles cases varied considerably throughout England during 2022/2023, with London continuing to be a hotspot. Towards the end of 2023, cases began to rise in the West Midlands and an outbreak is continuing through early 2024 (see Figure 3).
In London, none of the 32 local authorities met the 95% target for children to receive one dose of MMR vaccine at the age of two years. The average proportion of children who had received two doses of MMR vaccine at the age of five years was 74.0%, compared with 84.5% across England. Coverage ranged from 87.0% in Bromley to 56.3% in Hackney and City of London.
The low vaccination rates in London led NHS England to issue a warning in September 2023 that more than 32,000 children across the region were at risk of catching measles as the new school term got underway.
Vaccination rates in the West Midlands region were also lower than the national average during 2022/2023, with only 83.7% of children aged five years having received two doses of MMR vaccine. Coverage ranged from 90.6% in Worcestershire to 75.1% in Birmingham.
On 18 January 2024, the UK Health Security Agency (UKHSA) warned that the measles outbreak in the West Midlands could spread to other towns and cities if urgent action was not taken to boost uptake of MMR vaccination. It added that there had been 216 confirmed cases and 103 probable cases of measles in the West Midlands since 1 October 2023.
The UKHSA warned parents in the region not to send their children to school if they are showing symptoms of measles and schools were advised that anyone who has not had at least one dose of MMR and has been in contact with a case of measles should be excluded from school for 21 days.
Transmission
Measles is one of the world’s most contagious diseases, with nine in every ten non-immune people exposed becoming infected (see Figure 4). The virus is transmitted via airborne droplets and can remain on contaminated surfaces for up to two hours. It can be transmitted by an infected person from four days before the onset of the rash to four days after it appears.
Symptoms
Measles is characterised by cold-like symptoms and conjunctivitis, followed by a red-brown blotchy rash that starts on the head and spreads outwards to the rest of the body (see Figure 5).
The disease is usually a self-limiting condition, but it can result in serious and potentially life-threatening complications for some patients, with one in five children needing to be admitted to hospital for treatment. It tends to be more severe in adults, infants and immunocompromised people.
Complications can include otitis media, pneumonia, convulsions, encephalitis, blindness and, very rarely, subacute sclerosing panencephalitis, a progressive, disabling brain disorder, which can develop seven to ten years after the initial infection.
Contracting measles during pregnancy can cause miscarriage or stillbirth, premature birth and low birth weight.
Immune reset
Measles infection destroys immune memory cells, resetting previously acquired immunity and making it more likely that people who have had measles will catch other infections.
Results from a study of 77 unvaccinated children in the Netherlands in 2013 showed that the infection eliminated 11–73% of the repertoire of antibodies that protect against other pathogens. The same immune impairment did not happen in a control group who received the measles vaccine.
Previous research suggests that the process of immune system recovery can take up to three years.
Differential diagnosis
Several other common childhood illnesses have similar clinical presentations to measles, although the combination and timing of rash, fever, runny nose, sneezing, sore throat, cough and conjunctivitis is almost unique to measles (see Figure 6).
Path to increasing vaccination rates
In July 2023, the House of Commons Health and Social Care Committee said that expansion of the use of pharmacists in delivering routine vaccinations should be explored as part of a plan to tackle falling vaccination rates in the UK (see Figure 7).
Pharmacy leaders supported the idea, with Alastair Buxton, director of NHS services at Community Pharmacy England, saying that, subject to the right funding and support, the easily accessible network of pharmacies could provide a much wider range of NHS vaccination programmes. Malcolm Harrison, chief executive of the Company Chemists’ Association, said that “community pharmacy can be the home for all vaccinations” in the longer term.
NHS England published an ‘NHS vaccination strategy’ in December 2023, which proposed that integrated care boards should design vaccine delivery networks that tailor delivery to local communities and are as accessible as possible. The strategy did not mention pharmacies as a core setting for childhood immunisations; however, it said that adult routine vaccinations, which could include catch-up MMR vaccinations, are likely to be available from a range of locations, including pharmacies, and aligned with seasonal vaccinations where possible.
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It would be helpful if this article had descriptions, pictures and video that include darker skin tones.