Adults: Your Childhood Measles Shot May Not Protect You

For many adults, childhood vaccinations were a one-and-done event—something our parents handled, never to be questioned. But if you were vaccinated for measles between 1963 and 1988, your immunity may not be as strong as you think.

Some early vaccines were ineffective, and before 1989, most people only received one dose, which may not provide lifelong protection. That means many of us who assume we’re immune may actually be vulnerable to measles, one of the most contagious and potentially dangerous viruses.

False Sense of Security

Because vaccines dramatically reduced measles cases in the U.S., many have forgotten how serious the disease can be. Before the vaccine, thousands were hospitalized each year with complications like pneumonia, brain swelling, and even death.

Now, with declining vaccination rates and increased global travel, measles is making a comeback. If your immunity isn’t strong enough, you could be at risk.

Why Your Childhood Measles Shot May Not Be Enough

1. The 1963-1967 Vaccine May Not Have Worked

If you were vaccinated between 1963 and 1967, you might have received the inactivated (killed) measles vaccine, which was later found to provide little to no long-term protection. If that’s the case, you need at least one dose of the modern MMR (measles-mumps-rubella) vaccine.

2. You May Have Only Had One Dose

Before 1989, most people received just one dose of the measles vaccine. While one dose is 93% effective, two doses increase immunity to 97%, ensuring lifelong protection. If you only had one shot as a child, a booster is recommended—especially if you travel internationally or work in healthcare.

3. You May Not Have Natural Immunity

If you were born before 1957, you likely had measles as a child and are naturally immune. However, those born in the late 1950s through the 1960s fall into a gray area—some received the ineffective vaccine, some only had one dose, and some may not have lasting immunity at all.

4. Measles Is Back—and It’s Extremely Contagious

Declared eliminated in the U.S. in 2000, measles has surged back due to declining vaccination rates. The virus is one of the most contagious diseases on the planet—90% of unvaccinated people exposed will get sick. As international travel increases, so does the risk of exposure. Ensuring your immunity is strong is more important than ever.

How to Check If You Need a Booster

If you’re unsure about your measles immunity, here’s what you can do:

• Check your vaccination records: If you received the vaccine between 1963 and 1967, or only had one dose before 1989, you may need a booster.

• Get a measles titer test: A simple blood test can check your antibody levels. If they’re low, a booster is recommended.

• Talk to your doctor: If records are missing, most doctors will recommend getting an MMR shot just to be safe—there’s no harm in an extra dose.

What If You’re Unsure of Your Vaccination Status?

If you can’t confirm your vaccine history, getting an extra MMR dose is safe—the CDC confirms there’s no risk in receiving an additional shot. Most side effects are mild, including soreness, low fever, or a rash.

Who Should NOT Get the MMR Vaccine?

• Pregnant individuals (wait until after delivery)

• People with weakened immune systems (e.g., undergoing chemotherapy, HIV/AIDS)

• Those with severe allergies to gelatin or neomycin

For most adults, an MMR booster is a low-risk, high-reward way to ensure protection against measles, especially with outbreaks increasing.

Who Should Prioritize a Booster?

The CDC recommends full vaccination for:

✅ People vaccinated between 1963-1967 (who may have received the ineffective vaccine)

✅ People vaccinated before 1989 (who may have only had one dose)

✅ Healthcare workers

✅ International travelers

✅ College students or those in group living environments

✅ Anyone born between 1957 and 1968 who is unsure of their vaccination status

The Bottom Line

Many of us assume we’re protected against measles, but if you were vaccinated between 1963 and 1988, your immunity might not be as strong as you think. Measles is back, and checking your vaccination status now could protect you from a preventable but potentially serious disease.

A simple booster shot could provide lifelong immunity—and peace of mind.