What You Really Need to Know About Measles and the MMR Vaccine
Just 25 years ago , measles was declared eliminated from the United States. Cases were sometimes imported overseas from people traveling from Europe, Africa or Asia. But this year alone, there have been no deaths from measles in the United States; and only this year have we not had a notorious anti-vaxxer at the helm of our Department of Health and Human Services.
Department chief Robert F. Kennedy Jr. has given some recognition that vaccines play a role in preventing measles. The article , which appeared under his name on Fox News Channel, carefully sidestepped information about the need for vaccinations, saying that parents “should consult with their health care providers to understand their options” regarding the vaccine, and that “good nutrition remains the best defense against most chronic and infectious diseases.” Kennedy previously led an anti-vaccine propaganda organization that spread misinformation so blatant that it was removed from Facebook .
Compare his messages with those of the World Health Organization, which can put it more clearly: “Vaccination is the best way to prevent measles from getting or spreading to other people.” To this day, the CDC website still has accurate information about measles , including another simple statement that RFK Jr. couldn’t bring himself to say: “The best protection against measles is the measles, mumps, and rubella (MMR) vaccine.”
As public health officials in Texas and elsewhere do their best to contain the latest outbreaks, RFK Jr. has been on Fox News touting the “benefits” of measles and saying the vaccine is as bad as the disease itself. So, since people in charge of measles control are sending mixed messages, I want to make sure the message gets through. So here’s what you should know about measles and the measles vaccine.
The MMR or MMRV vaccines are the best protection against measles.
This is the first and most important thing to know: the measles vaccine protects you from measles. This is the best protection we have against measles , as both the Centers for Disease Control and Prevention (CDC) and WHO will openly tell you. The World Health Organization estimates that measles vaccination saved 60 million lives worldwide between 2000 and 2023. Most measles deaths occurred in children under 5 years of age who were not vaccinated or did not receive the recommended two doses on schedule.
There are two types of measles vaccine: the MMR vaccine, which provides protection against measles, mumps and rubella; and the MMRV vaccine, which covers these three diseases plus chickenpox, more commonly known as varicella.
The recommended schedule for MMR or MMRV vaccination is to receive the first dose at 12 to 15 months of age and the second dose at 4 to 6 years of age. Infants who travel or live in areas with a measles outbreak can receive a dose at 6 months, but this protection is not expected to last long, so they will still need two more doses on the regular schedule. Adults and older children may also receive a two-dose series (four weeks apart) if they did not receive it as children or do not remember whether they received it.
Measles is one of the most contagious diseases known and can be fatal.
Should you get vaccinated against measles? Yes, very much so. Anti-vaxxers like to point out that measles used to be a common childhood disease, which is true. But this does not mean that it is harmless. According to a 2013 CDC Vaccine Advisory Council report , before vaccination became common, there were 500,000 measles cases in the United States in a typical year. This resulted in 500 deaths, 48,000 hospitalizations and 1,000 cases of permanent brain damage from encephalitis.
Measles is also extremely contagious, possibly the most contagious human disease known. By comparison, the average person who gets the flu will spread it to 1.3 other people. For Ebola, the number is 1.8. For smallpox, before we eradicated it through vaccination, the rate was between 3.5 and 6. Chickenpox is at the top of the list, with every sick person infecting 10 to 12 more people. But measles surpasses even this, spreading to an average of 12 to 18 people. I get my numbers from this chart on Wikipedia . The exact number of each outbreak may depend on the specifics of when and where it occurs, but these statistics are fairly widely agreed upon.
Measles is so contagious that after an infected person leaves a room, the air and surfaces in that room can infect people within the next two hours . That’s why simply avoiding sick people isn’t enough, and that’s why authorities announce where and when a person with measles was known to be in public, such as at two wards at children’s hospitals in Philadelphia on March 7 and March 10 . Anyone who visited these locations during this time is encouraged to find out if they are protected from measles and to talk to their doctor about getting vaccinated if necessary.
Measles is much worse than the vaccine
Kennedy repeated a common and incorrect view of anti-vaxxers, saying that the measles vaccine “causes all the same diseases” as measles. No, the vaccine will not give you measles. Even if he meant “all the same symptoms,” that’s still not true.
He highlighted encephalitis, an inflammation of the brain that can lead to death or brain damage. The measles vaccine causes 1-2 cases of encephalitis per million children vaccinated. On the other hand, according to Encephalitis International , measles causes encephalitis in 1-3 out of every thousand sick children. In other words, measles has a 1000 times greater risk of encephalitis compared to the vaccine.
Kennedy also stated that the measles vaccine “causes death every year,” which is not true. The Infectious Diseases Society of America states : “No deaths associated with the MMR vaccine have been reported in healthy individuals.” There have been very few deaths from vaccine side effects among immunocompromised children, so the first step in getting the vaccine is to talk to a health care professional who can determine if it is safe for you to get the vaccine.
The vaccine can be given after exposure to the measles virus.
The best time to get the MMR vaccine is when you are young, 12–15 months and 4–6 years. The second best time if you’ve just contracted measles is now . A dose of the vaccine can be given within 72 hours of exposure to the virus to provide last-minute protection.
If you think you need the vaccine for this reason, contact your doctor. Another option is to get a dose of immunoglobulin instead. It must be one or the other, not both; globulin may cancel the vaccine.
Immunity to the vaccine may wane, but not as much as RFK Jr. thinks
After one dose of the MMR vaccine, you have a 93% chance of being protected against measles. After using both recommended doses, this figure increases to 97%. This is why two doses are recommended.
It is likely true that immunity from measles infection lasts longer than immunity from the vaccine, but the vaccine still provides lifelong protection to the vast majority of people who receive two doses. Kennedy said vaccinated people lose “4.5%” of their immunity each year. I don’t know where he got this figure from, but I found a study that postulated a decline of 0.04% per year – that’s about 100 times less than the figure he gave.
For God’s sake, you don’t need “natural” immunity.
In the 1950s and earlier, natural immunity from infection was the only immunity we had to measles. Everyone got sick anyway, because children were constantly being born without immunity to measles. Eventually they will encounter the virus and get sick. As I said above, for most children this was normal, but for some it was a disaster. Read Roald Dahl’s letter about his daughter dying of measles if you haven’t already. She was healthy, then had a regular case of measles, and then one day she felt “sleepy” and died shortly after.
The only way to gain natural immunity is to roll the dice. One child out of every 1,000 died from measles. The remaining 999 carry this immunity for life, but only because they were lucky. The goal of a vaccine is to give you immunity without the risk of complications or death.
Which means, sorry, no measles parties. Or as the Texas Department of State Health Services says : “No! DSHS strongly recommends against intentionally exposing anyone to infectious diseases such as measles.” As they rightly point out, you risk serious complications and death for partygoers, you can’t predict how severe the symptoms will be, and you create a bunch of walking measles carriers who can then spread the virus to the elderly, the unvaccinated, and the immunocompromised. On the other hand, vaccination provides protection to 97% of those who receive the vaccine, with a much lower risk of complications.
How to know if you need the measles vaccine
When I said that “everyone” had measles as a child, it is true enough that the Centers for Disease Control and Prevention (CDC) and other health authorities rely on this fact to know who is immune. If you were born before 1957 (so you will be 69 or older in 2025), you are expected to have already had a bout of measles.
You may also think you are immune if you have medical records showing that you have received two doses of measles vaccine, or that you have had a laboratory-confirmed case of measles, or that you have had a blood test that shows you are immune.
If you don’t remember whether you’ve had the vaccine, you can have your immunity tested, but it’s not necessary. As the Centers for Disease Control and Prevention (CDC) states , “There is no harm in getting another dose if you are already immune to measles, mumps, or rubella.”
If you are in Texas, which is currently experiencing the largest measles outbreak, this Texas Health and Human Services page has information on how to stay safe, including where to get the MMR vaccine in Texas.