Measles cases are on the rise − here’s how to make sure you’re protected

The Context:

There is a growing measles outbreak in the United States that began earlier this year.  In 2025, there have already been more diagnosed cases than all of 2024. It's an alarming trend, but could it reach Orange County or Apopka? There are several factors that could play a role in it spreading to Central Florida.

1. Increased Risk of Imported Cases

• While the outbreak is currently concentrated in Texas, New Mexico, and Oklahoma, the high level of interstate travel and tourism in Florida—especially in Central Florida near major theme parks and tourist destinations—means that cases could spread to Florida.
• Orange County’s status as a major tourist hub increases the risk of an infected traveler bringing measles into the area, which could lead to localized outbreaks.

2. Vaccination Status and Public Health Preparedness

• The article highlights that most measles cases are occurring in unvaccinated individuals. Florida, including Orange County, has seen increasing vaccine hesitancy in recent years, which could heighten the local risk of an outbreak.
• If measles cases begin to appear in Florida, the Orange County Health Department might recommend catch-up vaccination programs or enhanced surveillance.
• Residents who are uncertain about their vaccination status (especially those vaccinated between 1963–1967 or with only one dose) may be encouraged to check their records or consult with a healthcare provider.

3. Impact on Schools and Childcare Facilities

• Florida law requires children to be vaccinated before attending public schools, but there are medical and religious exemptions.
• If a measles case is reported in an Apopka school, students without proof of vaccination may face mandatory exclusion from school until the outbreak is contained, disrupting education and childcare for affected families.
• Daycares, summer camps, and other group settings where children congregate could face similar disruptions.

4. Healthcare System Pressure

• A local outbreak would increase demand for healthcare services in Orange County.
• Measles can cause complications like pneumonia, brain inflammation, and hospitalization, which could strain Apopka-area hospitals and clinics, particularly if multiple cases emerge simultaneously.

5. Economic and Community Impact

• If an outbreak were to spread to Apopka or Orange County, public health responses (such as quarantine measures or school closures) could disrupt local businesses and community events.
• Tourism, which is a key part of the Central Florida economy, could be affected if an outbreak generates negative publicity or public concern.

6. Public Health Messaging and Misinformation

• The article highlights that misinformation about vaccines could complicate the response.
• Health authorities in Orange County may need to issue clear guidance to residents about vaccine effectiveness and the importance of herd immunity to protect vulnerable populations.

Key Takeaway:

Apopka and Orange County are at increased risk for a measles outbreak due to high travel volume and potential vaccine gaps. Strengthening vaccination rates and public health communication will be crucial in preventing or mitigating the impact of any local cases.

Daniel Pastula of the University of Colorado Anschutz Medical Campus writes in The Conversation about how to protect yourself against measles.

 *****

The measles outbreak that started in Texas in late January continues to grow. As of March 18, 2025, confirmed cases in the outbreak, which now spans Texas, New Mexico and Oklahoma, reached 321, surpassing the number of confirmed cases recorded for all of the U.S. in 2024. The vast majority of cases are in people who are not vaccinated. Meanwhile, a lack of clarity from health authorities is leaving people with questions about whether they need to get revaccinated.

In a Q&A with The Conversation U.S., Daniel Pastula, a neurologist and medical epidemiologist from the University of Colorado Anschutz Medical Campus and Colorado School of Public Health, explained how and when you should take action.

Should adults get another shot of the measles vaccine?

The measles vaccine, which first became available in the U.S. in 1963, contains a live but significantly weakened strain of the measles virus. This modified strain is too weak to cause measles, but it is similar enough to the wild type measles virus to train the immune system to recognize it. Most people who have received the live measles vaccine won’t need an additional shot now, but here is what you need to know:

People born before 1957 are presumed to have lifelong immunity because measles was so contagious that almost everyone contracted it before age 15. Unless there are special circumstances, they probably don’t need a vaccine now.

Most people born after 1957 would have received the shot as children, so they should be set for life. Physicians and public health experts don’t recommend most people in this group get a second measles shot, though there are exceptions.

In 1989, a limited outbreak of measles occurred among vaccinated school children. In response, the recommendations changed from one dose of the live measles vaccine to two doses for children. People fully vaccinated as children after that year do not need any additional doses.

Exceptions to these guidelines

There are two special circumstances where the previous recommendations may not hold.

First, if you were vaccinated between 1963 and 1967, one of the measles vaccines available at the time consisted of just proteins from the virus rather than a live, weakened version of it. Researchers soon realized this inactivated, or “killed,” vaccine was less effective and didn’t provide long-term immunity. Unless you know for certain you received the live vaccine, physicians and public health experts recommend that people vaccinated during those years get one dose of the live vaccine at some point.

Second, if you fall into a high-risk group – for example, if you are a health care provider, are traveling internationally or attending college, physicians and public health experts generally recommend getting a second dose if you have only had one.

For most adults without such risk factors, physicians and public health experts do not routinely recommend a second dose if you have previously received one dose of a live measles vaccine. If you have questions or concerns about your situation, make sure to ask your health care provider.

Except in very rare circumstances, there is no recommendation for a third dose of the measles vaccine.

Can you find out whether you’ve been vaccinated?

You might be able to! It’s worth checking. States actually keep vaccine records specifically for this reason, where you can look up your vaccine records or that of your kids. Your high school or college may still have your records, and so might your pediatrician’s office.

Should you get your antibody levels checked?

For most people, probably not.

A titer test checks the level of antibodies in your blood, and some people are asking their doctor to check their titers to determine whether they are still immune to measles. The problem is, the level of antibodies in your blood does not necessarily reflect your level of immunity. That’s because antibodies are just one part of your immune system’s infection-fighting force. Having a low level of antibodies does not necessarily mean your immunity has waned.

Other crucial elements of your immune response include B cells, T cells and other immune cells, but a titer test does not show their capabilities. For example, memory B cells might not currently be making antibodies against the virus but are primed to quickly do so the next time they see it. This is why antibody and titer tests should be used only in specific cases, in consultation with your doctor.

One example of when an antibody test may be warranted is if you are a health care provider born before 1957 and you want to make sure you don’t need another dose of the vaccine. You would use a test to see whether you have measles antibodies. But in this case you would be looking for a yes or no answer; the total amount of antibodies may not be very informative.

Is natural immunity better than vaccine-induced immunity?

Natural immunity – that is, the immunity you get after having measles – is effective. However, the downside is that natural infection with a wild virus is very risky. Before 1963, measles caused close to 50,000 hospitalizations and about 500 deaths each year in the United States, usually in children. It also caused over 1,000 cases of severe brain inflammation every year and carried several other long-term risks, such as permanent hearing loss or the wipe out of immunity to other diseases.

The point of vaccines is to create immunity without the risks of severe infection. It is basically a dress rehearsal for the real thing. The immunity from a vaccine is effectively the same immunity you get from having measles itself – but vastly safer than encountering the wild virus unprotected. One dose is 93% effective at preventing measles and two doses are 97% effective, and any breakthrough cases are likely to be much milder than a full-blown case of measles.

Can the vaccine cause measles?

No, the measles vaccine cannot cause measles because it contains a significantly weakened strain that has limited ability to infect and damage cells.

Some have claimed without evidence that the current outbreak in Texas was caused by the measles vaccine.

As part of the outbreak investigation, however, CDC and the Texas Department of State Health Services analyzed the genome of the virus causing the current outbreak and identified it as a wild measles virus. Researchers classify measles virus strains based on their genetic characteristics, or genotypes. They identified the outbreak virus as wild type genotype D8, and not the weakened measles vaccine strain, which is genotype A.

What are the risks of the vaccine?

That is a very reasonable question. Because the measles vaccine is a live, weakened virus strain, it can cause a mild, measles-like syndrome. For example, some people might have a slight fever, a rash, or some slight joint pain. These symptoms generally go away in a day or two, and most people don’t experience them. But the vaccine cannot cause measles itself, as it does not contain the wild measles virus.

In extremely rare cases, people can experience more significant reactions to the measles vaccine. It is important to remember that every single medical or health intervention carries risks – and that includes all medications and over-the-counter supplements. According to all available evidence, however, comparing the potential benefits against potential risks reveals that the risks of a signficant reaction to the vaccine are much lower than the risks of severe outcomes from measles itself.

Being vaccinated not only protects you and your family, but it also protects vulnerable people in the community, such as infants, cancer patients and pregnant women, who cannot be vaccinated themselves.

This article is republished from The Conversation under a Creative Commons license.