Today, we’re answering common questions about the measles vaccine—specifically the MMR vaccine—to provide evidence-based information on vaccine safety. Measles vaccination is the most effective way to prevent measles, and understanding the facts will help you make an informed decision.
Measles Symptoms and Complications: Recognizing the Risks
Measles is a highly contagious viral infection that causes fever, cough, runny nose, and red, watery eyes, followed by a rash that spreads across the body. While most people recover, serious complications can occur, especially in young children and unvaccinated individuals. These include:
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- Hospitalization – About 1 in 5 unvaccinated people in the U.S. who get measles require hospitalization.
- Pneumonia – Up to 1 in 20 children with measles develops pneumonia, the most common cause of measles-related deaths.
- Encephalitis (brain swelling) – About 1 in 1,000 children with measles develop encephalitis, which can cause seizures, deafness, or intellectual disability.
- Death – 1 to 3 in every 1,000 children with measles die from respiratory or neurological complications.
- Pregnancy Risks – Unvaccinated pregnant women with measles risk premature birth or low birth weight in their babies.
According to CDC data, 301 measles cases have been reported in 15 states in 2025, with 38 hospitalizations (17%) and one confirmed measles-related death—the first in the U.S. since 2015.
Measles Vaccine Effectiveness and Schedule: Long-Term Protection
The MMR vaccine is the most effective way to prevent measles outbreaks. It also protects against mumps and rubella.
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- One dose of the MMR vaccine provides about 94% immunity against measles.
- Two doses increase lifelong protection to over 97%.
Recommended MMR Vaccination Schedule:
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- First dose at 12–15 months (not earlier).
- Second dose at 4–6 years.
- Infants traveling to areas with active outbreaks can receive an early dose at 6–11 months.
The first MMR vaccine was introduced in the U.S. in 1963, but it was less effective than the current version. At the time, only a single dose was recommended. As a result, individuals born in the 1960s may have lower immunity and should consider getting an MMR booster.
MMR Vaccine Safety: Addressing Misinformation
While vaccine hesitancy exists, the MMR vaccine is universally considered safe and effective. The risks of severe vaccine reactions are far lower than the risks associated with measles disease. For example, 1 to 3 in 1,000 children with measles will die, while no one has ever died from the MMR vaccine.
Common, Mild Reactions
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- Soreness at the injection site: 1 in 5 (20%)
- Fever: 1 in 6 (17%)
- Mild rash: 1 in 20 (5%)
- Temporary joint pain: (mostly in women): 1 in 4 adults (25%), rare in children
Less Common Reactions
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- Fever-related seizures: 1 in 3,000 to 4,000 (0.025%)
- Temporary low platelet count: 1 in 30,000 to 40,000 (0.003%)
Rare, Severe Reactions
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- Severe allergic reaction or encephalitis: Less than 1 in 1,000,000 (0.0001%)
Measles Outbreaks and Herd Immunity: Protecting the Community
Measles spreads through the air and from contaminated surfaces, remaining infectious for hours. A single infected person can spread measles to 18 others. These factors make measles one of the most contagious diseases in the world.
Measles Exposure: Prevention and Treatment Options
There is no antiviral treatment for measles once infected, but early intervention can reduce complications:
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- Supportive care: Hydration, fever management, and rest.
- High-dose Vitamin A therapy: Reduces mortality and complications, particularly in children with vitamin A deficiency.
- Measles immunoglobulin (Ig): A post-exposure option for high-risk individuals, including infants and pregnant women, within six days of exposure.
It is important to understand that none of these options actually treat measles infection or prevent its spread to unvaccinated or high-risk individuals.
Measles and MMR Vaccine: Just the Facts
There is a lot of misinformation about measles and vaccines. Here are the two essential facts:
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- Measles is highly contagious and can cause serious complications and death.
- The MMR vaccine is a safe, effective, and proven way to prevent measles.
Final Thoughts on MMR Vaccine
Measles vaccination is the best way to protect yourself and others. If you’re unsure of your immune status, check your records or talk to your healthcare provider. Staying informed helps combat vaccine hesitancy and misinformation, ensuring public health protection for everyone.
