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measles outbreak protect At CHOP, our doctors have been responding to a steady stream of questions from concerned parents who want to better understand the latest measles outbreak, how they can keep their kids protected and what the truth is in the debate about vaccinations.

What is happening now?

In March 2024, Centers for Disease Control Control and Prevention (CDC) issued a Health Advisory to advise of an increase in global and U.S. measles cases. This is concerning because of the highly contagious nature of measles.

Locations of recent Philadelphia-area measles exposures: none

What is measles?

Measles is a highly contagious, viral respiratory illness that can cause:

  • Cold-like symptoms, such as runny nose, cough or fever
  • Red, watery eyes, sometimes developing into pink eye (conjunctivitis)
  • Small white spots, known as Koplik’s spots, inside the mouth that develop about two to three days after other symptoms begin
  • A distinct blotchy, red rash that appears three to five days after the first symptoms and starts on the face and neck and spreads downward

Some people with measles may experience complications, such as pneumonia, swelling of the brain, seizures and — in extreme cases — death.

Once a common childhood illness that affected mostly preschool- and school-aged children, measles has been relatively nonexistent in the U.S. in recent years. This is the result of widespread vaccination. Measles vaccination is highly effective in preventing infection.

How can I protect my family during measles outbreaks?

The most important thing you can do is make sure all children and adults in your household are up to date on their recommended vaccinations — all of them.

Because measles is highly contagious, it’s also important for parents to take precautions with children who are either too young to be vaccinated or who cannot get the vaccine for medical reasons.

If you live in or are visiting an area where multiple cases of measles have recently been reported, it’s important to limit your susceptible child’s exposure to other people and public areas where infected people might have visited.

During periods when outbreaks are not occurring, it’s safe to run normal errands with your baby — just be sure to practice the usual precautions to keep your child from getting sick: Don’t allow strangers to hold or play with your baby; keep your child away from anyone with a fever, cough, or other respiratory symptoms; and make sure you and your family wash your hands regularly.

What should you do if you think you have been exposed to or infected with measles?

Due to the highly contagious nature of measles, please contact your healthcare provider before you arrive at a doctor’s office or care center if you believe you have been exposed to or may be infected with measles. They will give advice on precautions to take to avoid potentially exposing others. 

Can my child get vaccinated before they’re 12 months old?

A mother who has been immunized with the measles, mumps and rubella (MMR) vaccine or previously had the measles passes on antibodies to her unborn baby. She also continues to pass them to her children while breastfeeding. These antibodies provide protection for up to six months, and possibly longer. This is the main reason babies are not routinely recommended to get the vaccine before 1 year of age.

The current outbreak has not changed this recommendation. If the outbreak turns into an epidemic, however, it’s possible these recommendations could be changed at least temporarily.

The MMR vaccine is still recommended for children 6 months and older at least two weeks prior to international travel to countries or regions with ongoing measles transmission. Before your next trip, check your destination and CDC’s global travel notices.

If the vaccine is so effective, and 90 percent of U.S. population has been vaccinated, why is measles spreading?

The MMR vaccine is extremely effective — about 95 to 99 of 100 people who have been vaccinated will be protected. However, measles is extremely contagious. Any place crowds of people are gathered, a person with measles could expose many others.

Unfortunately, some of those exposed may not be immune because:

  • They are too young to be immunized.
  • They have a medical reason why they cannot be immunized.
  • They may never have received the vaccination by choice.
  • They are one of the rare few for whom the vaccine didn’t work.

For these reasons, measles can quickly spread through a population when unvaccinated persons are exposed. This is why staying up to date on vaccinations is so important: Vaccines break the chain of transmission. 

Is the measles vaccine safe?

Yes. Like any medicine, vaccines do have side effects, yet scientific studies have long confirmed the safety of the MMR vaccine. Concerns about vaccines causing autism have been addressed by dozens of scientific studies and have shown that children who receive vaccines are at no greater risk for developing autism than those who do not receive vaccines.

On the flip side, children who do not receive vaccines are at increased risk of suffering from a vaccine-preventable disease.

Get more information about measles and the MMR vaccine from CHOP’s Vaccine Education Center.

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