Dr. Diego Chaves-Gnecco, MD, MPH, FAAP
According to the CDC (Centers for Disease Control and Prevention), as of April 18, 2025, there have been 800 confirmed individual cases of measles in 25 states, including Pennsylvania. Most of those who contracted measles were not vaccinated. Of these cases, 11% (85) required hospitalization, and two people have died. Measles can spread when it enters a community in the U.S. where groups of people are unvaccinated. Although measles was declared eliminated from the United States in the year 2000, several outbreaks have occurred in recent years.
What is Measles? Measles is a highly contagious and potentially serious viral disease, especially dangerous for young children. It can cause severe complications and even death. The virus is transmitted through respiratory secretions such as saliva or mucus.
What are the Symptoms of Measles? Measles initially presents with nasal congestion, mucus discharge, cough, conjunctivitis, red eyes, and fever. After these symptoms, a rash of red spots appears, beginning on the head and eventually spreading to the rest of the body. Measles can lead to complications that affect vital organs. Severe complications are more common in children under 5 years old and adults over 20. These include pneumonia (lung infection), encephalitis (brain infection), pericarditis or myocarditis (heart infections), and, in some cases, death. Out of every 1,000 children who contract measles, one to two will die from the disease. In 2008, measles caused approximately 164,000 deaths worldwide—that’s about 450 deaths per day or 18 deaths every hour.
How is Measles Spread? Measles is extremely contagious. The likelihood of infection is 90% in individuals who are not vaccinated. Measles is even more contagious than COVID-19; while one person with COVID-19 might infect one to three people, one person with measles can infect up to 18. Transmission occurs through contact with an infected person’s respiratory secretions, such as mucus or saliva droplets expelled by coughing or sneezing. Infected individuals can spread the virus before showing any symptoms or before they know they are sick. The contagious period ranges from 6 to 19 days—typically beginning 5 days before the rash appears and lasting up to 4 days after it appears.
How is Measles Prevented? The two main ways to prevent measles are avoiding contact with infected individuals and getting vaccinated. If someone is suspected of having measles, it’s important to call a doctor. Visiting a clinic or emergency room is discouraged, as it may expose others to the virus. Currently, two doses of the measles vaccine are recommended. The vaccine is part of the MMR combination, which also protects against rubella and mumps. The first dose should be given after the first year of life, and the second dose at age four. However, it is advisable to update immunizations at any age beyond that. Adolescents and adults should also consider getting vaccinated.
If you are planning to travel internationally, it is essential to ensure that your vaccines are up to date, including the measles vaccine. Babies under one year of age—as early as 6 months old—can receive an early dose of the vaccine if traveling abroad or to areas experiencing outbreaks. This early dose is additional and does not count as one of the two routine doses, so children in this situation will receive a total of three doses.
It is important to emphasize that the measles vaccine is not linked to autism. Numerous studies have shown there is no connection between the vaccine and the development of autism. Talk to your doctor and make sure that you and your loved ones are protected against measles.
