Measles outbreak

Measles symptoms typically appear 7 to 14 days after exposure. People who have a high fever (101°F (38.3°C) or higher) and a cough, runny nose, or red eyes may have early stages of measles. A rash will usually appear after 4 days of fever. If you do develop symptoms you should stay away from other people and call a healthcare provider. Call first before you go to a clinic or hospital so they can prepare for your arrival and prevent other people from exposure.

We strongly encourage parents to talk to their healthcare provider about getting an early MMR vaccine for their children, even if they have not been exposed to someone with measles.

Because measles is spreading throughout Utah, we suggest you talk to a healthcare provider about giving your infant an early, extra dose of the MMR vaccine if they are older than 6 months and younger than 12 months old. 

It is a standard recommendation that infants 6–11 months old get an early, extra dose if they are traveling internationally or to an area where measles is spreading. Given the high levels of measles in Utah it is now appropriate to consider this early, extra for all Utah infants of this age.

Any infant who gets a dose before 12 months old will need to get 2 later doses in accordance with the standard vaccination schedule at 12–15 months and then a dose at 4–6 years.

Young children can get their second MMR dose before 4 years old. The protection after 1 dose is very good. However, getting the second dose before the age of 4 is completely appropriate and fully protective, as long as they are older than 12 months and it has been at least 28 days since their first dose. Parents should discuss this option with their healthcare provider.

Two doses of the MMR vaccine provide lifelong protection against measles and you do not need a booster. If you or your child have not had 2 doses of the MMR or MMRV vaccine, we suggest you talk with a healthcare provider about getting vaccinated.

Special considerations:

• Before 1990, only 1 dose of MMR was recommended. If you were vaccinated before 1990 you may not have received your second dose. Talk with a healthcare provider about getting your second dose.
• Some people who were vaccinated between the years 1963 and 1967 got a less effective vaccine, which means they can still get measles. Anyone who got this vaccine is considered unvaccinated. Talk to a healthcare provider about whether you should get revaccinated if you were vaccinated between 1963 and 1967.
• If you were born before 1957, you likely do not need the MMR since we assume you were infected with measles in the past.

We recommend everyone make sure you are protected against measles. Talk to a healthcare provider if you have questions about whether you are protected against measles.

Most states look at how many kindergarten students have an exemption for the measles vaccine to measure measles vaccination rates. 

During the 2025/2026 school year: 

• 12% of in-person kindergarten students in Utah had an exemption for the MMR vaccine or were missing documentation to show they were vaccinated against measles. 
• Nearly 12% of in-person kindergarten students in Utah had an exemption to any school-required vaccine. 
• 12.7% of all students in Utah had an exemption to any school-required vaccine, including students in online schools. 

You can look up the immunization coverage rates for children in Utah on the Utah Statistics page of the immunization program website. The immunization dashboard school vaccine exemption tab contains statewide and school-specific immunization data. You can also find reports that show trends in school vaccine exemptions for the past 10 years.

To avoid the chance of measles infection for unvaccinated individuals we recommend the following:

• Surround yourself with other vaccinated persons, especially in your household, if possible.
• If you’re exposed to someone who has the measles, talk to a doctor about post-exposure vaccination or medication.
• Avoid large gatherings and crowded places in areas with known outbreaks and ongoing transmission.
• Consider getting the MMR vaccine at least 1 month before you try to get pregnant, to avoid harm to your baby during pregnancy.
• Stay away from others if they are sick.

If you think you or your child may have measles, we recommend you:

• Stay home and away from others as much as possible.
• Seek care if you have a hard time breathing and/or fever won’t come down.
• Call the clinic or provider ahead of time and let them know you are concerned about measles; this is to protect other people from getting exposed in the waiting area, such as pregnant women and babies.

Find out more about measles in each state by visiting their website:

• Arizona
• Colorado
• Idaho
• Nevada
• New Mexico
• Wyoming

While the measles vaccine is very good at protecting people from getting sick with measles, it is not perfect. Most people who get the vaccine (97%) are well protected, but about 3% can get sick if they are exposed to the measles virus. During an outbreak, breakthrough infections are expected because high levels of the measles virus are circulating in the community. Two doses of the MMR vaccine are highly effective (97%) at preventing measles. Even a single dose is very effective (93%). It is rare to get a breakthrough infection if you’ve had 2 doses of the MMR vaccine.

Experts aren’t exactly sure why breakthrough infections happen. It could be that someone’s immune system did not fully respond to the vaccine. Breakthrough infections can also happen in people who have medical conditions  or take medications that weaken their body so it cannot fight off the infection even when they have been vaccinated.

Breakthrough infections are more likely to happen in people who have only had 1 dose of the MMR vaccine.

If a vaccinated person gets measles, there are still benefits from the vaccine. Vaccinated people are less likely to have severe illness or have severe measles complications. They are also less likely to spread the virus to others.

Even though the MMR vaccine is very effective, it is not 100% effective. This means we can still expect a small percentage of vaccinated people to get sick with measles after being exposed. For example, if 100 vaccinated people are exposed to measles, we can expect about 3 of them to get sick with measles (a breakthrough infection). If 200 vaccinated people are exposed, we can expect about 6 of them to get sick, and so on. This means that with an increasing number of vaccinated people being exposed, we end up with an increasing number of breakthrough infections.

Most people (more than 90%) in Utah have been vaccinated against measles. We believe many hundreds of vaccinated people in Utah have been exposed to measles during the current widespread outbreak. Even though hundreds of vaccinated people have likely been exposed, the vast majority of them have been protected by the vaccine and we only see the few where their body was not able to fight the virus off.

At the same time, a small proportion of Utahns have not been vaccinated. Those people are also being exposed to the virus. Unlike the vaccinated Utahns, a majority of the unvaccinated Utahns who are exposed to the virus will get sick with measles. This is why most of the people getting measles in Utah are unvaccinated even though they make up a small minority of our population.

Most people with 2 doses of the MMR vaccine are well protected, however the risk is not zero.

• It’s rare, but sometimes people who are fully vaccinated (have had 2 doses of the MMR vaccine) can still get infected if they are exposed. This means you should avoid contact with people who have measles (if possible).
• Breakthrough infections are more common when someone lives in a household, or has prolonged close contact, with someone who has measles. 
• Adults with only 1 dose of MMR are still at risk for a mild case of measles.

Yes, it is still reasonable to watch for symptoms. While it is quite rare, it is possible for vaccinated people to get measles. If you have been exposed and experience measles-like symptoms, contact your local health department or a healthcare provider for further assessment and testing.

Currently, about 10% of confirmed measles cases are breakthrough cases. This is consistent with national data trends for areas experiencing a measles outbreak.