Health

Everything Parents Need To Know About The MMR Vaccine

And no, the vaccine doesn't cause autism.

by Sara Novak
Updated: 
Originally Published: 
A medical professional wearing gloves gives a young boy the MMR vaccine.
Karl Tapales/Getty

A routine childhood vaccination, the MMR vaccine protects against measles, mumps, and rubella: three diseases that once put American children at risk of death or permanent disability. Before the vaccine, nearly all children contracted measles because it was so infectious. Each year, 400 to 500 children died of the disease and 48,000 were hospitalized. Mumps was similarly virulent; before immunization, it was considered the most common cause of hearing loss and meningitis in children. And according to the Centers for Disease Control and Prevention, in just one year before the vaccine became available, 12.5 million Americans contracted rubella, or German measles, which triggered an estimated 11,000 miscarriages and 2,100 newborn deaths.

But today, through the wonders of modern medicine, parents are, for the most part, unaware of the trauma these diseases caused just half a century ago. And in so many ways, the MMR vaccine is a victim of its own success. Since all three diseases have been largely eradicated in the United States due to widespread vaccination, it’s easy to forget the devastation they once caused — until outbreaks caused by anti-vaxxers propel these preventable diseases into the limelight.

Why Children (And Some Adults) Need the MMR Vaccine

Even though measles, mumps, and rubella have been largely eradicated due to widespread vaccination, outbreaks still happen in the U.S. and elsewhere. And since all three viruses can spread like wildfire, you want to make sure your child is protected in case an outbreak does crop up around you. Parents should make sure they’re immunized too, so that they’re protected and don’t spread the disease in the case of an outbreak.

Not to mention that a growing anti-vaccination movement further puts communities at risk. According to a 2018 study, several anti-vax hotspots have arisen throughout the nation in areas such as Seattle, Portland, Salt Lake City, and Houston, making the population increasingly vulnerable to outbreaks.

All three of these diseases can be deadly, and getting your children vaccinated protects your family and community. Two doses of the vaccine are 97% effective against measles, 88% effective against the mumps, and 97% effective against rubella. Vaccinated people who do become infected are more likely to have a milder illness and less likely to transmit the disease to others.

MMR Vaccine Schedule

  • All children should get two doses of the MMR vaccine: the first when they’re between 12 and 15 months, and the second between 4 and 6 years old.
  • Kids can receive the second dose earlier, as long as it’s at least 28 days from the first dose.
  • Adults who don’t have evidence they received the MMR vaccine as children should get at least one dose of the vaccine.
  • Adults who don’t have evidence that they were vaccinated with MMR as children should get two doses separated by at least 28 days if they work for educational institutions, travel internationally, or are healthcare workers.
  • Adults who could potentially become pregnant and who don’t have evidence of vaccination should get at least one dose to pass on protection to their potential babies until they can be vaccinated at age 1.

If you were born before 1957, you probably don’t need to get the MMR vaccine because you’ve likely been exposed to these diseases and have already built up immunity against them.

MMR Vaccine Ingredients

The MMR vaccine is an attenuated live virus vaccine. This means that it’s made with live viruses that have been weakened in the lab. The weakened viruses stimulate the immune system to protect you from the real measles, mumps, and rubella viruses, without getting you sick in the process.

In addition to the weakened viruses, the MMR vaccine contains the following:

The Ingredient: Vitamins

In: Most vaccines

Purpose: Boosts body’s response to the vaccine

The Ingredient: Amino acids

In: Most vaccines

Purpose: Preservative

The Ingredient: Fetal bovine serum

In: Most vaccines

Purpose: Boosts body’s response to the vaccine

The Ingredient: Sucrose

In: Most vaccines

Use: Preservative

The Ingredient: Glutamate

In: Most vaccines

Use: Preservative/stabilizer to protect it from high heat or deep freezes

The Ingredient: Recombinant human albumin

In: Most vaccines

Use: Preservative/stabilizer to protect it from high heat or deep freezes

The Ingredient: Neomycin

In: Most vaccines

Use: Kills viruses or inactivates toxins

The Ingredient: Sorbitol

In: Most vaccines

Use: Preservative

The Ingredient: Hydrolyzed gelatin

In: Most vaccines

Use: Preservative

The Ingredient: Sodium phosphate

In: Most vaccines

Use: Boosts the effectiveness of the vaccine

The Ingredient: Sodium chloride

In: Most vaccines

Use: Preservative

MMR Vaccine Side Effects

Some mild side effects are common, such as a sore arm at the injection site, fever, and temporary joint pain. In rare cases, the MMR vaccine may cause mild seizures. In children younger than 7, there is a very small increased risk of febrile seizures after MMR vaccination, occurring in about 1 in 3,000 to 4,000 children, according to the CDC.

MMR Vaccine Rash

About 5% of children may also develop a mild rash 1 to 2 weeks after getting the MMR vaccine. The rash usually appears on the necks and arms, and it may occasionally spread to other parts of the body. This happens because although the vaccine can’t infect you with the weakened viruses it contains, it may cause mild symptoms of illness. The rash should go away within a few weeks without treatment. If it gets worse, talk to your doctor.

Why Some People Don’t Get the MMR Vaccine (And Why They’re Wrong)

Some parents don’t get their children the MMR vaccine because they think that measles, mumps, and rubella have been largely eliminated. But because all three diseases are so highly infectious, outbreaks can happen wherever even a small minority of the population is unvaccinated.

The most common false narrative of anti-vaxxers is that the MMR vaccine causes autism, but research has shown time and time again that there is no connection between autism and the vaccine. The one 1998 Lancet paper that falsely stated this has been retracted for several reasons, including that the 12 children written about in the paper were hand-selected, had invasive and unethical tests done on them, and the main author received funding from lawyers who were suing the vaccine manufacturers. That main author has lost his medical license.

The bottom line: The MMR vaccine is safe, effective, and our best tool for keeping children safe from measles, mumps, and rubella, three dangerous and highly infectious diseases.

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