This article was posted on MLive. Read more here.
Michigan has had two confirmed measles infections in 2025, the latest reported Wednesday, April 1, in Kent County.
Nationally, the U.S. has identified more than 483 cases across 20 states — a 70% increase from the total cases documented in all of 2024, and the highest total since 2019.
Measles is known for being highly contagious, with its ability to live up to two hours in an airspace after an infected person leaves the area. Without immunity, the likelihood of being infected after exposure to the virus is about 90%, according to state and federal health officials.
Doctors warn that measles is more than just a rash. About 14% of recorded cases this year have required hospitalization, including 40 children younger than 5. There has been one confirmed U.S. measles death, and a second under investigation.
Below are some measles questions recently fielded by MLive and Michigan health officials, along with related answers from doctors, the U.S. Centers for Disease Control and Prevention, and the Michigan Department of Health and Human Services (MDHHS):
Do adults need booster shots for measles?
Most people who received both doses of the existing live attenuated measles vaccine (MMR- measles, mumps, and rubella) will have lifelong immunity and won’t need a booster shot, said Dr. Rosey Olivero, a pediatric infectious disease physician at Corewell Health Helen DeVos Children’s Hospital.
One exception is for health care workers and those who are immune-compromised. Those populations may need their antibody levels measured to determine if an additional shot is warranted.
Another exception is for older people who received the previous, inactivated measles vaccine between 1963 and 1967. That shot was determined to be less effective and was replaced by today’s attenuated vaccine. If you got a measles shot during that period in the 60s, your doctor may recommend at least one dose of the modern MMR vaccine.
If you had measles as a kid, do you need to be vaccinated as an adult?
No, like the vaccine, a previous measles infection induces lifelong immunity, explained Dr. Russ Lampen, an infectious disease physician at Corewell Health.
Should I get my child vaccinated earlier than the recommended 12 months?
The MMR vaccine is recommended for children 12 months to 15 months, with a follow-up dose between ages 4 and 6 years old.
Dr. Olivero said there are a few circumstances in which a child should get vaccinated under an accelerated schedule.
One such case is if the child will become immune-suppressed. That may be due to cancer, undergoing chemotherapy, starting an immune-suppressant medication, expecting a transplant, or anticipating use of high-dose steroids for conditions like asthma.
Another exception would be if a child at least 6 months, but younger than 1 year, plans to travel internationally.
Children can get an early dose of MMR vaccine between 6 months and 12 months, but they’ll still need two doses once they reach appropriate age to be considered fully vaccinated.
That’s because infants younger than 1 year old have high levels of maternal antibodies in their bloodstream, doctors said. Because the MMR vaccine is a weakened live virus, it can be neutralized by those antibodies, reducing long-term effectiveness.
The state health department said parents should talk to their health care provider if they have questions about whether their child should get vaccinated before 6 months of age.
Is measles preventable?
The medical community calls the MMR vaccine the best way to prevent measles. The vaccine was developed in 1971, and improved in 2005 when the varicella vaccine was added to create the MMRV vaccine.
Two doses of MMR vaccine is considered 97% effective at preventing measles, while one dose is about 93% effective, according to the CDC.
The community goal for herd immunity is 95% vaccination uptake.
As of December 2024, only 80.4% of Michigan children age 19 months to 35 months had received at least one dose of MMR vaccine, which trailed the national average (93.4%).
Can you get measles if you’re fully vaccinated?
While it’s unlikely, it is possible to be infected with measles despite being fully vaccinated. However, doctors from Helen DeVos Children’s Hospital said they’re very unlikely to become ill from the infection.
Of the 483 confirmed measles cases in the U.S. this year, 97% were unvaccinated or unknown vaccination status.