Cases of measles are on the rise in 2025.
So far, the Ohio Department of Health reports 10 cases in Ohio and 483 cases in 20 states, according to the CDC.
As numbers increase across the country, so are the questions I’m receiving about this highly contagious and potentially serious disease. Here’s what families need to know about measles today:
1. The measles infection spreads easily.
People with measles infection are contagious from four days before developing a rash through four days after the rash appears. If you’re not immune and you come into contact with measles, there’s a 90% chance you’ll get it. You are immune if you’ve previously had the infection or have received both vaccines.
Measles spreads through tiny droplets when someone breathes, coughs or sneezes. These droplets stay in the air for up to two hours! That means you can catch measles even after an infected person leaves the room.
2. The vaccine is highly effective.
One dose of the MMR (measles, mumps, rubella) vaccine is 93% effective at preventing any measles infection. Two doses protect more than 97% of people for life. The MMR vaccine stops people from getting any symptoms of infection.
3. The vaccine is safe.
Many studies conducted in multiple countries, including the US, have shown that the MMR vaccine is safe. The vaccine’s benefits far outweigh the common side effects that we see after vaccination. Those can include a temporary, mild rash, fever, soreness at the injection site and temporary stiffness of the joints. These go away after a few days and the side effects do not mean that someone has measles or can spread it. The CDC outlines more safety data on their website.
4. When kids get the MMR vaccine.
Most children receive the first dose of MMR vaccine at 12-15 months and the second dose before starting kindergarten. Talk to your doctor if your baby is younger than 12 months and you are traveling to an area with active measles cases.
5. Herd immunity is like protective armor.
Herd immunity happens when a large portion of the population is immune to a certain infection – either through natural infection or vaccination. The more people who are immune, the less likely it will spread through the community.
For most diseases, we need 80% immunity to prevent an outbreak. But because measles is so contagious, we need 95% of people to be immune to prevent an outbreak. In Ohio, only 89.2% of kindergarteners had the MMR vaccine in 2023-24, putting us at risk for a measles outbreak. In comparison, Gaines County, Texas, which has a large measles outbreak, has an 82% vaccine rate against measles. This is only a few percentage points lower than our state.
6. Vaccinated kids are well-protected.
If your kids got both doses of the MMR vaccine, their risk of getting measles is extremely low. My kids had both MMR doses and I feel confident about them taking part in their usual activities and visiting family members who have underlying medical conditions. Having both doses means they are unlikely to get sick from measles or spread measles to others.
7. What symptoms look like.
Symptoms usually start with 4-7 days of a runny nose, cough, red and watery eyes, and high fevers. After up to a week of those symptoms, patients develop a rash that starts along the hairline and then spreads to the hands and feet. It lasts about five days and fevers can persist during this time. Most people fully recover in a couple of weeks after their symptoms first appear.
8. It’s hard to predict who will develop complications.
Most people who get measles will be miserable for a couple of weeks but recover fully. Pregnant people, children under five and people with weak immune systems are at the highest risk of developing serious complications. However, measles is tricky because even the healthiest kids and adults can have serious complications. Before we had a measles vaccine, there were 500 deaths in the U.S. every year from measles. These deaths were mostly in healthy children. Now that we have the MMR vaccine available, we can prevent this infection and the risk of complications.
Mild complications that are common:
- Dehydration.
- Ear infections.
Serious complications that typically start days-to-weeks into the illness:
- Hospitalization (1 in 5 unvaccinated kids).
- Pneumonia (1 in 20 unvaccinated kids).
- Brain swelling (1 in 1,000 cases) leading to permanent neurologic damage in 25% of survivors. This can include blindness, deafness, and seizures.
- Death (1 to 3 in 1,000 cases).
- Fatal brain disease (10 in 100,000 cases) up to 10 years after infection.
9. Talk to your doctor about any concerns.
If you’re not sure if your kids are up to date on their vaccines, call your doctor or your local health department to check your records. If you have concerns about the MMR vaccine, talk to your doctor. Most pediatricians are parents themselves or have loved ones who are children. We work in healthcare because we are passionate about doing what’s right for kids. And we want our patient families to feel comfortable discussing their healthcare concerns, choices and even flaws in the healthcare system with us. Our job is to work as a team to help your child be as healthy as possible.
To learn more about Infectious Diseases at Cincinnati Children’s, or to schedule an appointment, please call 513-636-4578.
