Measles Outbreak in London: A Growing Threat to Unvaccinated Children
A measles outbreak in London is currently impacting unvaccinated children under the age of 10, coinciding with a significant increase in infections worldwide. This development follows the UK's recent loss of its measles-free status, as designated by the World Health Organization (WHO), alongside five other countries. Health experts are urgently calling for governments to enhance vaccination rates to curb the spread of this highly contagious virus.
What Is Measles and How Does It Spread?
Measles is a highly infectious viral illness that spreads easily among individuals who are not fully vaccinated. The disease typically begins with cold-like symptoms, followed by a distinctive rash that appears a few days later. This rash starts on the face and behind the ears before extending to the rest of the body. The spots are often raised and may merge into blotchy patches, though they are not usually itchy. Some individuals might also develop small spots inside their mouth.
The virus is transmitted when an infected person breathes, coughs, or sneezes, with one case capable of generating up to 18 secondary infections. Unvaccinated individuals have a 90% chance of contracting measles if exposed. A person remains infectious from the onset of symptoms, approximately four days before the rash appears, until four days after the rash develops.
Risks and Complications of Measles
While many people recover from measles, the illness can lead to severe complications such as pneumonia or brain inflammation. In rare instances, it may result in long-term disability or death. Babies and those with weakened immune systems are particularly vulnerable. Additionally, measles can cause miscarriage, stillbirth, premature birth, or low birthweight in pregnant women.
Despite the availability of a safe and cost-effective vaccine, the WHO reported 95,000 measles deaths globally in 2024, predominantly among unvaccinated children under five years old.
Why Are Measles Cases Increasing Globally?
Measles is entirely preventable through vaccination but remains highly contagious, often rebounding when vaccination rates decline. Health experts attribute the rise in outbreaks worldwide to growing vaccine skepticism and mistrust, exacerbated by the Covid-19 pandemic. In January, the UK, along with Spain, Austria, Armenia, Azerbaijan, and Uzbekistan, lost its measles-free status, which requires an absence of endemic cases for at least 12 months. Other European nations, such as France and Romania, already experience regular transmission, while Canada lost its elimination status in 2025, and the US faces similar challenges.
How to Protect Your Child from Measles
There is no specific treatment for measles, but two doses of a measles vaccine offer high levels of protection and help prevent outbreaks. Both the MMRV and MMR vaccines protect against measles, mumps, and rubella, with the MMRV vaccine also covering chickenpox. These vaccines are typically administered to children at 12 months and 18 months of age.
To reduce the risk of spreading measles, health experts recommend:
- Opening windows and doors to improve ventilation.
- Frequently washing hands with soap and warm water.
- Using tissues when coughing or sneezing and disposing of them immediately.
- Avoiding sharing cutlery, cups, towels, clothes, or bedding.
Signs and Symptoms to Monitor
Symptoms of measles usually emerge 10 to 14 days after exposure to the virus, with a prominent rash being the most visible indicator. Early symptoms, lasting four to seven days, include a runny nose, cough, red and watery eyes, and small white spots inside the cheeks. The rash typically begins seven to 18 days after exposure, starting on the face and upper neck, and spreads over three days to the hands and feet, lasting up to a week before fading.
The Importance of Herd Immunity
Herd immunity, achieved through community-wide vaccination, is the only effective way to prevent measles. The WHO sets a threshold of 95% vaccination coverage due to the virus's high infectivity, as it can remain contagious in the air or on surfaces for up to two hours. In the UK, only 84% of children received the two necessary doses for full protection in 2024, leading to 2,911 confirmed cases in England that year—the highest since 2012. Globally, first-dose measles vaccine coverage was 84% in 2024, down from 86% in 2019.
