The United States is witnessing its worst measles outbreak since 1991, with nearly 3,900 reported cases. According to the US Centres for Disease Control and Prevention, a total of 3,887 confirmed measles cases were reported in the United States as of October 1, 2026. A total of 18 measles cases were reported among international visitors to the United States. On Monday, New York has declared a disaster emergency as measles cases continue to spike in neighbouring states and in rural areas.

A total of 1,004 measles cases have also been reported in Pennsylvania, US. The Pennsylvania health department has informed that the state is grappling with a fast-growing outbreak with 198 hospitalisations and five deaths as of October 5. Lancaster County remains the hardest-hit area in the state with 391 cases. All five individuals who have succumbed to the illness in Pennsylvania were not vaccinated.

The Health Authorities have attributed such outbreaks to low vaccination rates.

Understanding measles and vaccination

For the unserved, measles is a highly contagious and potentially severe viral respiratory illness, characterised by a distinct red rash, high fever, and respiratory symptoms. Although it typically infects children, anyone who is unvaccinated can contract the disease.

How it spreads

Measles spreads through respiratory droplets that are expelled when an infected person coughs or sneezes. The virus can remain infectious in the air or on surfaces for up to two hours, making it easy to contract in crowded places. It is highly contagious; if one person has measles, about 90% of the non-immune individuals nearby will also become infected.

An infected person can spread the virus from four days before the rash appears until four days after it first emerges.

Symptoms of measles

The symptoms of measles typically appear about 10 to 14 days after exposure and may include:

  • High fever
  • Cough
  • Runny nose
  • Red, watery eyes
  • Koplik spots (small white spots inside the mouth)
  • A red, blotchy skin rash that usually begins at the head and spreads to the rest of the body

Complications can arise, including pneumonia, encephalitis, and in some cases, death, particularly in unvaccinated individuals or those with compromised immune systems.

Prevention tips

The best way to prevent measles is through vaccination.

  • MMR Vaccine

The measles vaccine, often given as part of the MMR vaccine (measles, mumps, and rubella), is safe and highly effective. It is typically administered in two doses, the first between 12-15 months of age and the second between 4-6 years.

  • Herd immunity

High vaccination coverage in the community helps protect those who cannot be vaccinated, such as infants and individuals with certain medical conditions.

  • Avoiding exposure

Stay away from infected individuals and crowded places during outbreaks. If you are unvaccinated and exposed to measles, you may need to quarantine to prevent spreading the virus.

  • Good hygiene practices

Regular handwashing and using tissues or your elbow to cover your mouth when coughing or sneezing can help reduce the spread of various infections.

People who have not been vaccinated and have been exposed to the virus can get the vaccine within a 72-hour window, or they may receive immune globulin within six days to help prevent or reduce the severity of the illness.



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