First some perspective… 

Measles was declared “eliminated” in the US in 2000. That’s a designation given to countries that have not had continuous spread of measles for more than a year. 

This year, we’ve hit a 33-year high in confirmed measles cases. As of yesterday, there have been 1288 cases across 39 states — surpassing 2019’s pre-pandemic peak. 162 of those patients were hospitalized. Tragically, this year we’ve seen three confirmed measles-related deaths, the first in ten years. 

About 90% of this year’s infections are among unvaccinated individuals — especially in communities with low vaccination coverage, such as parts of Texas, New Mexico, and Kansas. But the remaining 10% — infections in people who have been vaccinated — are prompting questions about how long immunity lasts. 

Vaccines in general have lost ground among Americans since vaccine mandates during COVID became a bit political and raised a “whose body is it anyway?” individual-rights issue. Vaccination rates have been trending downward since then and measles outbreaks have been increasing. 

Why are “outbreaks” important?

An outbreak is defined as three or more related cases in a jurisdiction. Outbreak numbers are important because outbreaks occur in areas with lower overall vaccination rates. The more outbreaks there are, the more opportunities measles has to spread continuously — and the more likely we are to lose our hard-won “elimination status.” The risk also increases for older adults, especially those who were never vaccinated or whose childhood immunity may have faded over time.

Are outbreaks on the rise?

100%! There have been 27 outbreaks reported so far this year, and 88% of confirmed cases (1,130 of 1,288) are outbreak-associated. For comparison, 16 outbreaks were reported during 2024 and 69% of cases (198 of 285) were outbreak-associated. You may be wondering about the non-outbreak-associated cases. They generally occur thanks to international travel. An American resident picks it up elsewhere and brings the disease home, or a visitor brings measles into the US. In truth, those cases are not really non-outbreak cases. They are simply associated with another country’s outbreak. So, let’s call them non-US outbreak cases. 

These cases don’t become outbreaks when the infected traveler brings the disease into a well-vaccinated area, because it is unlikely they will come into contact with someone lacking immunity. But measles is one of the most contagious diseases on earth — and when it’s introduced into an area with low vaccination rates, it can spread quickly. That’s when those of us vaccinated in the distant past may become at risk.

How can vaccinated people still get measles?

There are several reasons “vaccinated” people can still get measles. Bear with us for some pretty interesting history:

Back in the day, US health officials assumed that every child born before 1959 had already survived a case of the measles, giving them strong natural immunity. But we now know that not everyone in that group contracted the disease. Those who didn’t likely avoided infection thanks to the vaccination efforts that began after the first two measles vaccines were approved in the US in 1963 — and therefore may not have immunity.

Now about those vaccines: They were new and just not as good as the MMR (measles, mumps, and rubella) vaccine is today. Also, we were in the data collection stage, not the health policy stage during the 1960s. Many children didn’t receive a vaccine or only received one dose of a shorter-acting vaccine. So many of us born before 1971 have little to no immunity. 

What about the MMR vaccine?

In 1971, an upgraded combination of three existing vaccines was approved and instantly promoted because it covered three diseases (measles, mumps, and rubella) and reduced “vaccine fatigue.” The MMR vaccine is about 97% effective after two doses, offering long-lasting protection — but nothing in biology lasts forever. A few scenarios stand out:

• Waning immunity: Studies (e.g., in England and the US) show that vaccine-derived antibodies can slowly decline after 10–20 years. 

• Early vaccination: Infants vaccinated before 8.5 months may experience faster immunity drop-off, needing a full booster schedule later.

• Rare vaccine failure: No vaccine is perfect — and in rare cases, vaccinated individuals may still become infected, especially if their immunity is lower.

Should you worry about waning or no immunity?

If any of these apply, you might consider checking up on your protection:

• You were born before 1971 and are not sure if you’ve ever had the measles.

• You received your second MMR dose more than 15–20 years ago.

• You were vaccinated as an infant — especially before 1 year old — or only got one dose.

• You’re in a high-risk group: healthcare workers, college dorm residents, childhood/infant caregivers, or live in an area with outbreaks like West Texas or New Mexico.

• You’re immunocompromised or caring for someone who is.

How can you tell if you have immunity?

• Check your records: Two MMR doses by age six typically ensure strong, long-term protection.

• Get a measles antibody titer test: A simple blood test (IgG) can measure measles immunity. A positive result suggests immunity, while a negative or equivocal result may indicate a need for vaccination. Medical professionals can interpret the levels to confirm if you’re still protected.

The Bottom Line:

Do you need to take action?

If you are unvaccinated and want immunity, get the MMR vaccine — ideally two doses, four weeks apart.

If you are unsure of your status, dig out your old immunization records or get an IgG titer test.

If you were vaccinated long ago, get an IgG titer test and consider a booster.

If you are a high-risk worker or a caregiver, talk to a medical professional about testing and/or boosting.

If you live in a community with low vaccination coverage, your immunity status is important, so get an IgG titer test and consider a booster.

Remember that while measles is more contagious than COVID, it is less deadly. Use what you’ve learned to assess your possible risk and decide how to protect yourself and your loved ones against what will most likely be an increasing number of measles outbreaks in the days and years ahead. Knowledge is power!

At Amaze, we’re proud to be your healthcare partner. And of course we’re always here to help when you need us.