Helping Patients Understand Measles Vaccination and Vitamin A: Clinician Guidance

Published May 13, 2025

This resource is designed to support clinicians with talking points as they develop preventive and treatment plans in collaboration with patients and their families or caregivers.

History

Vitamin A

Measles Vaccine

In 1992, vitamin A deficiency was recognized as a risk factor for  severe measles.  

In 1997, The World Health Organization (WHO) and United Nations International Children’s Fund (UNICEF) recommended that 200,000 IU of vitamin A be given to children with measles who were over the age of one year and lived in areas where vitamin A deficiency may be prevalent.

Vitamin A deficiency is uncommon in high resource countries like the United States.

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The MMR vaccine was developed by Maurie Hilleman and licensed by Merck in 1971.  Measles resulted in 2.6 million deaths per year before immunization became common. By 2012, over 575 million doses had been administered worldwide and measles associated mortality fell dramatically.  Two doses of MMR vaccine is 97% effective in preventing  measles.

Vaccine History

 

 

Safety

Vitamin A

Measles Vaccine

Vitamin A can be toxic when given in large doses. Symptoms include nausea, vomiting, headache, tiredness, joint and bone pain.  Serious problems can include high pressure in the brain, liver damage, and coma.

Prophylaxis:

While vitamin A plays an important role in supporting the immune system, current evidence shows that it does not prevent measles in children who are not vitamin A deficient.

Do not give vitamin A to a child to prevent measles.  It does not work and may make children sick.

Treatment:

If a child has measles, a doctor can give  2 doses of vitamin A to treat a vitamin A deficiency.

Measles is a serious infection.  One in 5 unvaccinated people in the US who get measles will be hospitalized.  One out of every 20 children with measles will develop pneumonia, the most common cause of death from measles in young children.  One out of 1000 children who get measles will develop encephalitis, which is swelling of the brain.  One to three out of every 1,000 children with measles will die from infection in their lungs and brain.

Prophylaxis:

The MMR vaccine is the best way to protect children from measles.

Treatment:

Once a person has measles, there is no specific treatment that works against the measles virus.  The best care is supportive care.

Efficacy

Vitamin A

Measles Vaccine

Vitamin A may be used as a supportive treatment if a child has been diagnosed with a vitamin A deficiency – this decision should be guided by the pediatrician. Treating a deficiency may help lessen the severity of measles symptoms. However, vitamin A does not prevent measles infection and should not be relied on as a substitute for vaccination.

The measles vaccine is very effective. Two doses of measles vaccine is about 97% effective at preventing measles if exposed to the virus. One dose is about 93% effective.

If someone who is fully vaccinated does get measles, they are more likely to have a much milder case than someone who hasn’t been vaccinated.

If a child has been exposed to measles, getting the MMR vaccine within 72 hours can still offer some protection – it might prevent the illness altogether or at least help make it milder.

It’s completely safe for breastfeeding moms to get the MMR vaccine. It won’t affect the baby, and breastfeeding doesn’t interfere with how well the vaccine works.

First, most vaccines a child receives does not  contain live viruses – and when they do, like in the case of the MMR vaccine, it’s a weakened form that can’t cause the actual disease in healthy individuals. Vaccines also don’t cause the virus they are meant to protect against, and they aren’t designed to cure an illness once someone is already sick. Their role is to help the immune system build protection ahead of time.