The alarming rise in measles cases in the United States has health officials on high alert. Since the outbreak began in Texas in late January, the number of confirmed cases has skyrocketed, reaching a staggering 321 by March 18, 2025. This figure not only surpasses the total number of reported cases nationwide in 2024 but also highlights a concerning trend as outbreaks extend into neighboring states like New Mexico and Oklahoma. The vast majority of those affected are individuals who have not been vaccinated, raising urgent questions about vaccination protocols and immunity.

Do You Need Another Measles Vaccine?

The original measles vaccine was introduced in the U.S. in 1963. It contains a weakened form of the virus, designed to trigger immunity without causing the disease. Here's how it works and what you should know about your vaccination status:

For Those Born Before 1957:

Most individuals born before this year are presumed to have natural lifetime immunity because measles was highly contagious, and many were infected during childhood. Unless there are specific medical concerns, these individuals likely do not require further vaccination.

For Most Adults Born After 1957:

Generally, if you received the measles vaccination as a child, you are considered immune for life. However, following a limited outbreak among vaccinated children in 1989, health authorities updated guidelines to require two doses of the vaccine, starting from children born after that year. If you are fully vaccinated after 1989, there’s typically no need for additional shots.

Exceptions for Revaccination:

There are exceptions to these recommendations. If you received the vaccine between 1963 and 1967, it’s essential to check whether you received the live version of the vaccine since the earlier, inactivated version was less effective. For anyone unsure, especially those in high-risk groups like healthcare professionals or international travelers, a second dose is often recommended.

Finding Your Vaccination Records:

If you’re unsure of your vaccination status, check with your state health department or your school records. Many schools and pediatric offices maintain vaccination records that can be accessed.

Understanding Antibody Testing:

While some individuals contemplate getting their antibody levels checked through a titer test, this may not be necessary for most. The immune system is complex, and simply measuring antibodies doesn’t provide a complete picture of immunity. Consult your healthcare provider if you think antibody testing might be warranted for specific health circumstances.

Natural Immunity vs. Vaccine-Induced Immunity:

While natural immunity acquired from contracting measles is strong, acquiring it comes with dangers. Prior to the vaccine's introduction, measles was responsible for thousands of hospitalizations and deaths annually, particularly among children. Vaccination offers a safe alternative, granting the body immunity without the severe risks of the disease itself.

Can the Vaccine Cause Measles?

No, the measles vaccine cannot cause the disease since it contains a weakened virus strain that does not possess the ability to cause illness. Investigations into the recent outbreak confirmed that it is caused by a wild strain of the virus, not from the vaccine.

What Are the Risks of the Measles Vaccine?

As with any medical intervention, there can be side effects from the measles vaccine, typically mild and short-lived, such as fever or a rash. Severe reactions are extremely rare. It’s crucial to weigh the risks of the vaccine against the potential severe consequences of contracting measles, which historically include hospitalizations and even death.

As the situation continues to evolve, staying informed about vaccinations and public health recommendations is essential. Ensure that you are protected and that your loved ones are too as we face this resurgence of a preventable disease.