Measles is one of the most contagious viruses on the entire planet. According to the Centers for Disease Control and Prevention, if one person has it, up to 90% of people close to that person who are not immune will also become infected. It spreads through the air when an infected person coughs or sneezes, and the virus can remain in a room’s air for up to two hours after the sick person has left. Before a vaccine was invented, almost every single child caught this illness.
Anne Kamwila, Healthcare Policy Analyst, shares, “Today, because fewer people are getting vaccinated, outbreaks of this dangerous disease are happening again in communities all over the world. When these outbreaks make the evening news, people naturally start to worry about their own and their families’ health.” A very common question is whether people can catch measles a second time. If you had it as a child, or if you got the shots, are you truly safe forever, or do you have to worry about getting sick all over again?
What do claims say about measles reinfection?
It is very easy to find claims on the internet or hear stories from older family members saying that a person can catch the measles multiple times. People often think this because of how other common sicknesses work. We all know that you can catch the common cold dozens of times in your life. We also know that you can get the flu every single year, and people can catch COVID-19 more than once. Because we are so used to catching viruses over and over again, it makes sense that people assume this specific virus works the same way.
You might also hear a grandparent say that they definitely had the measles twice when they were growing up in the 1950s or 60s. Because they remember being sick with a horrible, full-body rash on two separate occasions, they firmly believe that the illness can strike the same person multiple times. This leads to a lot of fear that the protection we get from our childhood sickness or from our vaccines will eventually wear off and leave us completely vulnerable as adults.
What the science actually says
The wonderful news is that science is very clear on this topic. You cannot get measles twice. Once you have had the full illness and survived it, your body develops what medical experts call lifelong immunity, according to Michigan Medicine. This means your immune system will remember exactly what the virus looks like until the day you die.
When a virus enters your body, your immune system acts like a police force. It fights the invader and creates special proteins called antibodies to destroy it. After the fight is over, your body keeps a few “memory cells” that serve as a permanent wanted poster for that specific virus. The Centers for Disease Control and Prevention explains that because the measles virus does not mutate or change its shape like the flu virus does, your immune memory cells will always recognize it.
If the virus ever tries to enter your nose or lungs again, your immune system will destroy it before you even feel a single symptom. The same lifelong protection applies to people who have received the two recommended doses of the MMR vaccine, as the National Health Service explains.
Why the misconception about measles exists
If science says you cannot catch it twice, why do so many older adults swear that they did? The confusion stems from the fact that, before modern blood tests, health experts had to diagnose illnesses solely by looking at the patient. Many different childhood viruses cause a high fever and a red, blotchy rash.
A person who thinks they had the disease twice likely had two completely different illnesses. For example, they might have had the actual measles one year, and then caught rubella the next year. Rubella, also called German measles, adds to the severe confusion, but a completely different germ causes it, the Cleveland Clinic explains.
They might also have had roseola, or fifth disease, or even a severe allergic reaction that caused a rash. Without a laboratory test to prove exactly which virus was in their blood, it was incredibly easy for parents and doctors to mistakenly label any severe childhood rash as measles.
The real risks
Because you cannot catch measles twice, the real danger is catching it for the very first time. This is not just a harmless rash that goes away in a few days. It is a severe respiratory disease that can cause terrible damage to the body.
As noted by the Mayo Clinic, common complications include severe ear infections that can lead to permanent hearing loss and dangerous lung infections such as pneumonia. In severe cases, the virus can travel to the brain and cause a deadly swelling called encephalitis.
There is another terrifying risk that scientists have recently discovered. PubMed Central notes that contracting the wild measles virus can cause a condition known as immune amnesia. The virus specifically attacks and destroys the immune memory cells that protect you from other diseases. This means that after you recover, your immune system forgets how to fight off sicknesses you previously had, leaving you highly vulnerable to catching the flu, strep throat and other dangerous infections for several years afterward, based on a publication in The Guardian.
What are the first signs of measles?
When one first catches the virus, it does not look like a rash at all. For the first few days, it looks exactly like a terrible, miserable cold. A person will develop a very high fever that can spike to 104 degrees, according to the Cleveland Clinic. They will also develop a harsh cough, a very runny nose and red, watery eyes that are highly sensitive to bright lights.
Two or three days after these cold symptoms begin, tiny white spots might appear on the inside of the cheeks and the roof of the mouth. These are called Koplik spots, and they are a clear warning sign. About three to five days after the first symptoms started, the famous rash appears. It usually begins as flat red spots along the hairline and the face, then rapidly spreads downward to the neck, chest, arms and legs.
Do adults need to get a measles booster?
Most adults are fully protected and do not need any additional shots. If you have written records showing you received two doses of the MMR vaccine as a child, you are considered protected for life. Furthermore, if you were born before 1957, doctors presume you are naturally immune because the virus was so widespread back then that almost everyone caught it, according to the New York State Department of Health.
However, there are a few exceptions. If you work in a hospital, if you are a student attending college, or if you are planning to travel internationally, you should have proof of immunity. Also, the Mayo Clinic states that adults who received a specific, less effective version of the vaccine between 1963 and 1967 might not be fully protected.
“It isn’t necessary to get a booster shot if you’re fully vaccinated with two doses of the MMR vaccine. The vaccine provides lifelong protection in most cases. Even in the onset of an outbreak, it isn’t recommended to receive a booster. Although there aren’t significant risks to receiving an extra dose for most individuals, there also aren’t any evidence-based benefits,” says Laraine Washer, M.D., professor of internal medicine and medical director of infection prevention at the University of Michigan Health.
If you are unsure about your status or your history, you can easily ask your doctor to perform a simple blood test to check your antibody levels. If your levels are low, the doctor will give you a safe booster shot.
What is the cure for measles?
There is no prescription medication or antibiotic that can cure or kill the virus once you have it. Because it is a viral infection, antibiotics will not work. The only thing you can do is provide supportive care while the patient’s immune system fights the battle. This means the sick person needs to get plenty of rest and drink large amounts of water to prevent dehydration from the high fever. You can use over-the-counter medicines like acetaminophen or ibuprofen to reduce fever and relieve muscle aches.
The sick person should also be kept in a dimly lit room to soothe their painful, sensitive eyes. If a person develops trouble breathing or severe chest pain, they must be taken to the hospital immediately, as they may need oxygen or intensive care for pneumonia.
If a child is diagnosed with a severe case of the measles, doctors will often give them a high dose of Vitamin A. The virus rapidly destroys the body’s natural supply of this vital nutrient. Giving a child a potent Vitamin A supplement has been proven to significantly reduce the risk of severe complications, especially preventing the terrible eye damage that can lead to permanent blindness.
Bottom line
You cannot get the measles twice because the virus does not change shape, allowing your immune system to remember it and provide lifelong protection after a single infection or complete vaccination. The misconception that you can catch it multiple times stems from confusing it with other childhood rashes, such as rubella or roseola, before modern blood tests existed. The real danger lies in the initial infection, which can cause severe complications and wipe out your immune system’s memory of other diseases, making the preventive MMR vaccine essential.
Frequently Asked Questions
Can I catch measles if I was vaccinated as a child?
It is extremely rare to catch the illness if you received two doses of the vaccine, as it provides absolute lifelong protection for about 97% of all people who get it.
How long are you contagious after measles?
You are highly contagious and can easily spread the virus to others from four days before the rash appears until four days after the rash first shows up on your skin.
Citations
Centers for Disease Control and Prevention. Measles (Rubeola). Centers for Disease Control and Prevention. Published May 29, 2024. https://www.cdc.gov/measles/about/index.html
Falconer L. Measles: 10 things to know about immunization and prevention. Michiganmedicine.org. Published February 28, 2024. https://www.michiganmedicine.org/health-lab/measles-10-things-know-about-immunization-and-prevention
Centers for Disease Control and Prevention. Measles cases and outbreaks. Measles (Rubeola). Published April 25, 2025. https://www.cdc.gov/measles/data-research/index.html
NHS. MMR (measles, mumps and rubella) vaccine. nhs.uk. Published March 8, 2024. https://www.nhs.uk/vaccinations/mmr-vaccine/
Cleveland Clinic. Rubella (German Measles): Symptoms,Treatment & Prevention. Cleveland Clinic. Published August 25, 2022. https://my.clevelandclinic.org/health/diseases/17798-rubella
Mayo Clinic. Measles – Symptoms and causes. Mayo Clinic. Published April 23, 2025. https://www.mayoclinic.org/diseases-conditions/measles/symptoms-causes/syc-20374857
Morales GB, Muñoz MA. Immune amnesia induced by measles and its effects on concurrent epidemics. Journal of the Royal Society, Interface. 2021;18(179):20210153. doi:https://doi.org/10.1098/rsif.2021.0153
Devlin H. Measles wipes out immune system’s memory, study finds. the Guardian. Published October 31, 2019. https://www.theguardian.com/science/2019/oct/31/measles-wipes-out-immune-systems-memory-study-finds
Cleveland Clinic. Measles: What Is It, Symptoms, Treatment & Prevention. Cleveland Clinic. Published February 28, 2025. https://my.clevelandclinic.org/health/diseases/8584-measles
Jain P, Rathee M. Koplik Spots. PubMed. Published 2020. https://www.ncbi.nlm.nih.gov/books/NBK549793/
New York State Department of Health. Measles Update. www.health.ny.gov. https://www.health.ny.gov/diseases/communicable/measles/
Scherger S. Answers to 3 common questions about measles. Mayo Clinic Health System. Published May 17, 2024. https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/common-questions-about-measles