London’s Looming Threat: Unveiling the Potential for a Devastating Measles Outbreak

London at Risk of Major Measles Outbreak, UK Health Security Agency Warns

Last Modified: Fri 14 Jul 2023 18.54 BST

Introduction

The UK Health Security Agency (UKHSA) has issued a warning that London is at risk of a major measles outbreak if there is no improvement in measles, mumps, and rubella (MMR) vaccination rates. According to fresh analysis by the UKHSA, without an increase in MMR vaccine take-up, the capital could experience an outbreak ranging between 40,000 and 160,000 cases. This scale of outbreak could result in dozens of deaths and thousands of hospitalizations. Official data indicates a steady rise in measles cases this year, with 128 cases reported between January and June, compared to 54 cases in the whole of 2022. 66% of the cases have been detected in London, although cases have been seen in all regions.

The Risks and Consequences

Measles is a highly contagious viral infection that can lead to severe illness. The UKHSA estimates that 20-40% of children affected by measles will be hospitalized. The US Centers for Disease Control and Prevention states that one to two in every 1,000 children infected with measles will die, with a larger number suffering serious complications such as intellectual disabilities and deafness. Prof. Paul Hunter, a medicine professor at the University of East Anglia, supports the UKHSA’s concerns and warns that an outbreak on the scale described could result in dozens of deaths. Measles is particularly dangerous for young children and individuals with weakened immune systems, but adults can also experience severe illness.

Vaccination Rates and Herd Immunity

In order to maintain herd immunity against measles, the World Health Organization (WHO) recommends a target vaccination uptake of 95%. However, the UK is well below this target, with first-dose MMR vaccine coverage for two-year-olds in England at 85.6%, the lowest level in a decade. In some parts of London, coverage for the first MMR dose at age two is as low as 69.5%. When vaccine uptake rates fall, individuals cannot rely on herd immunity to protect them if they are not immunized themselves. The MMR vaccine rate in London is approaching a critical point where herd immunity is no longer effective in preventing outbreaks. Vaccine scare stories in the early 2000s, linked to discredited doctor Andrew Wakefield, have contributed to low MMR vaccination rates, particularly among 19- to 25-year-olds.

Risks Outside of London

While the risk of a large measles outbreak is low outside of London, the UKHSA’s modelling suggests the potential for smaller outbreaks in specific populations, including teenagers, young people, and under-vaccinated groups such as the Charedi Orthodox Jewish community, Travellers, and recent migrants.

Recommendations and Preventive Measures

The MMR vaccine is part of the NHS routine childhood immunization program, and the UKHSA urges parents whose infants missed out on the vaccine, as well as unvaccinated individuals of any age, to come forward for vaccination. Parents should ensure their children are fully vaccinated with two MMR doses, which provides 99% lifelong protection. The NHS has launched a national campaign to encourage MMR vaccine uptake, including targeted outreach work in London for those at highest risk and in communities with the lowest uptake. Primary school children who have missed one or both doses of the MMR vaccine are being offered the opportunity to catch up at school, and parents of these children will be contacted by the NHS school immunization service. Parents of younger children or those who are home-schooled can make an appointment with their GP practice or visit a community clinic to access the vaccine.

Conclusion

The risk of a major measles outbreak in London highlights the urgent need to improve MMR vaccination rates. Measles can have severe consequences, and a large-scale outbreak could result in significant morbidity and mortality. It is crucial for individuals, parents, and communities to prioritize vaccination and ensure they are protected against this highly contagious virus. By taking proactive measures and ensuring high vaccine uptake rates, the potential for future outbreaks can be minimized, protecting the overall health and well-being of the population.