Why is measles spreading in London?

What health officials say about the outbreak

Public health teams in north-east London are responding to a rapid rise in confirmed cases among young children, with several admissions to hospital. The outbreak has largely affected children who were not protected by the two doses of MMR vaccine that health authorities recommend. Low uptake, delays in childhood immunisation, and clusters of unvaccinated children in particular communities have created pockets where the virus can spread quickly.

Measles is extremely contagious; it can be transmitted by respiratory droplets and can linger in air-filled spaces for hours after an infected person leaves. In settings such as schools and nurseries, one infectious child can seed multiple secondary cases if vaccination coverage is incomplete.

Why this matters

• Measles can cause serious complications including pneumonia, encephalitis, and hospitalization, especially in the very young.
• Even a small fall in vaccine coverage undermines community protection and allows outbreaks to grow.
• Outbreaks stress paediatric and public-health services through increased clinic visits, contact tracing, and the need for urgent vaccination campaigns.

What authorities are doing

Health bodies are ramping up contact tracing, offering catch-up MMR vaccinations and warning families to check records. In some instances, close contacts who are unvaccinated may be excluded from school for a period to limit transmission. Local clinics and school-based programmes are being used to deliver catch-up doses quickly.

What parents should consider

• Check your child’s immunisation record and book any missing MMR doses promptly.
• If a child develops fever with rash, seek medical advice and avoid exposing others.
• Pregnant women and infants too young for vaccination should avoid contact with suspected cases.

It’s still unclear how large the outbreak will become, but rapid vaccination of unprotected children is the most effective tool to halt further spread.