This blog was medically reviewed by Gigi Chawla, MD, MHA, pediatrician and clinical vice president of general pediatrics at Children’s Minnesota.
Measles was once considered eliminated in the United States, but outbreaks continue to occur when the virus is introduced into communities with lower vaccination rates. Measles is one of the most contagious diseases in the world, meaning it can spread easily to others. Even one case can cause an outbreak.
Many parents have never seen a case of measles. Knowing how it spreads, recognizing the symptoms and staying up to date on vaccines can help protect your child, family and others in your community.
What is measles and how does it spread?
Measles is a highly contagious viral illness that spreads easily through the air when an infected person coughs, sneezes, breathes or talks. If someone with measles goes into a room, the virus can stay in the air and on surfaces for up to two hours after they leave. That means someone who is not protected can get sick even if they never meet a person with measles.
On average, a person infected with measles can spread the virus to as many as 9 to 10 others if they are not vaccinated. To compare, one person with the common cold can infect up to three people on average.
Because it spreads so easily, measles can move quickly through schools, childcare settings and other community spaces when people are not protected through vaccination.
What are the symptoms of measles?
Measles can make children very sick. Early symptoms usually begin 7 to 14 days after becoming infected and often include:
- High fever
- Cough
- Runny nose
- Red, watery eyes
Small white spots, called Koplik spots, may also appear inside the mouth in the cheek area.
A red or brownish rash usually appears a few days after the first symptoms. The rash often starts on the head and spreads down the body.
Why is measles a concern?
Many childhood illnesses last a week or so and go away without serious problems. Measles is different.
While many children recover from measles, the illness can cause serious health problems. Babies younger than 12 months are especially at risk because they are typically too young to receive a measles vaccination.
Potential health complications from measles include:
- Ear infections
- Pneumonia
- Swelling of the brain (encephalitis)
- In rare cases, death
Other people who are at higher risk of having serious health issues from measles include:
- Children 5 years old and younger
- Pregnant women
- People with conditions that weaken the immune system, such as leukemia
How can families prevent measles?
The most effective way to prevent measles is vaccination. On average in the U.S., about 95% of measles cases are in people who are unvaccinated.
Children typically receive the measles, mumps and rubella (MMR) vaccine in two doses. The first dose is recommended at 12 to 15 months of age, and the second dose is recommended at 4 to 6 years of age before a child starts school.
Vaccination protects more than the child getting the vaccine. When enough people are vaccinated, measles has a harder time spreading. This helps protect babies and others who cannot be vaccinated for different reasons.
Parents should review their child’s immunization record and make sure vaccinations are up to date. Delaying or missing a vaccine can leave children unprotected when they need it most.
How effective is the MMR vaccine?
The MMR vaccine has been studied for decades and has a strong record of safety and effectiveness.
One dose of the MMR vaccine is about 93% effective at preventing infection. Completing the recommended two-dose series increases protection to about 97% effectiveness.
The second dose is important because not every child develops protection after the first dose. The second dose helps ensure that nearly all children develop protection against measles.
Is the MMR vaccine safe?
Yes. The MMR vaccine has been used for decades and is continually monitored for safety.
Most side effects are mild and temporary and may include:
- Soreness where the shot was given
- Mild fever
- In rare cases, a temporary rash
The MMR vaccine does not cause autism and serious side effects are very rare. For most children, the benefits of vaccination far outweigh the risks that come with a measles infection.
What if parents have questions about vaccines?
It’s normal for parents to have questions about their child’s health and vaccines.
The best source of information is your child’s pediatrician or healthcare team. They understand your child’s medical history and can provide guidance based on scientific evidence and established medical recommendations.
What should parents do if they think their child was exposed?
If you believe your child was exposed to measles:
- Before going to a clinic or hospital, call your healthcare provider.
- Describe the exposure and any symptoms your child is experiencing.
- Follow instructions from your healthcare team about testing, evaluation or next steps.
Calling ahead helps healthcare teams take steps to protect other patients and families from potential exposure.
The bottom line
Measles remains a serious and highly contagious disease, but it is also preventable. Staying current on recommended vaccinations and talking with your child’s healthcare provider are the best ways to protect your child and your community.
If you have questions about measles, vaccine schedules or your child’s immunization status, our primary care team at Children’s Minnesota can help. Together, you can make informed decisions that support your child’s health and well-being.
