Dr. Michael Colli said difficult conversations about childhood vaccines are becoming easier. With cases of measles rising nationwide, he has more parents’ attention.
“When the numbers are low, those conversations are harder because you’re trying to protect against this mystery virus,” said Dr. Colli, a pediatrician from Keystone Health in Chambersburg, Pa. “Once (the numbers) start going up, it becomes easier.”
Once considered eliminated in North America, measles has returned in a big way. Outbreaks in Texas and New Jersey in early 2025 highlight the dangers of this highly contagious virus, especially to children.
Measles cases in 2024 were five times higher than in 2023 (288 compared to 58), according to the Center for Disease Control and Prevention (CDC). Nearly three-quarters of those cases were patients 19 years or younger.
In 2025, the outbreak in West Texas alone has produced 146 cases as of March 1.
1. How serious is measles?
Measles can cause serious and lasting health effects.
“Measles is not just a rash,” said Dr. Jeremy Wigginton, Chief Medical Officer at Capital Blue Cross. “It can have very serious complications, including ear infections that lead to permanent hearing loss, pneumonia, and encephalitis (swelling of the brain).”
In the February 2025 outbreak in West Texas, one child died and some patients had serious enough respiratory issues that they needed an oxygen tube to breathe.
2. How contagious is measles?
When more people develop immunity to a virus – usually through vaccines – it becomes more difficult to spread.
But achieving herd immunity is different for every virus and depends on how contagious it is. Measles, for example, spreads so easily that an estimated 95% of the population needs to be vaccinated to reach herd immunity.
“Measles is one of the most contagious viruses,” Dr. Colli said, adding that only two doses of the measles, mumps, and rubella (MMR) vaccine can provide lifelong protection for most people.
3. Why is measles making a resurgence?
After being eliminated in the U.S. in 2000, measles returned due to unvaccinated international travelers, according to the CDC. Health experts point to declining vaccination rates in the U.S. as another reason for the increase in cases. In most states, children are required to get the MMR vaccine before entering kindergarten. But kindergarten classes in 37 states have vaccination rates below the 95% needed for herd immunity, according to CDC data.
One of those states is Pennsylvania, which had vaccinated 95% of its incoming kindergarteners from 2017-2022 until dropping below that mark for the 2022-2023 school year.
Of the 2024 measles cases, the CDC said 89% were unvaccinated.
4. What if I can’t remember getting vaccinated for measles as a kid?
If you’re an adult of a certain age, you may not remember getting an MMR vaccine as a child. It’s also possible that you don’t have access to your medical records from decades ago.
What are ways to find this information?
Dr. Wigginton said to start by asking your primary care physician or family members for vaccine records.
Another place to look is your state’s department of health. While there is no national database that collects information on vaccines, states and some major cities have vaccine registries.
A third option would be to get a blood test to see whether you have antibodies against certain viral infections. If you’re still unsure but want protection, it is OK to get another dose of the MMR vaccine, Dr. Wigginton said.
The real risk lies in not having protection through a vaccine,” Dr. Wigginton said. “It leaves yourself, your family, and others in your community vulnerable to these highly contagious and potentially life-threatening illnesses.
Vaccine Insurance Coverage
Because it is a preventive measure, the MMR vaccine is covered by most health plans offered by Capital Blue Cross if you meet criteria set by the CDC, said Michael Ballow, a clinical pharmacist at Capital Blue Cross.
The information provided is meant for a general audience. Capital Blue Cross and its affiliated companies believe this health education resource provides useful information but does not assume any liability associated with its use.
