Measles is the most contagious infectious disease in people. The only way to prevent it is with the measles vaccine.
Recently, Health and Human Services Secretary Robert F. Kennedy Jr. promoted the Centers for Disease Control and Prevention’s recommendations on vitamin A to treat the measles infection. But there is a big difference between treating an illness and preventing it. Unfortunately, online conversations among parents began to shift to discuss cod-liver oil, vitamin A and other nutritional strategies as a primary method to prevent the disease.
To suggest that vitamins, good nutrition or other remedies can prevent measles is misleading and dangerous.
Research does show that vitamin A can help children with deficiencies after they’re infected with measles, but the vast majority of children in the United States do not fall into that category. To suggest that vitamins, good nutrition or other remedies can prevent measles is misleading and dangerous. The immune system simply doesn’t work that way.
The first time your immune system encounters a new threat — such as a virus or a bacteria — it needs to learn how to create protective antibodies. This is what vaccines do. Just like a child learns to read from a beginner text, a vaccine teaches the immune system how to “read” a virus long before it encounters the real thing.
As a pediatrician, I’ve seen firsthand how children can suffer from diseases like this one, for which we have no cures and still fairly minimal treatments. Doctors can help alleviate symptoms and try to prevent the most severe complications, such as pneumonia, which occurs in as many as 1 in 20 children, and encephalitis, which occurs in 1 in 1,000 cases. Even with the best care, 1 to 3 of every 1,000 people with measles will die. As of Friday afternoon, 198 people have been infected as a result of an outbreak in Texas and one child has died. There have also been 30 reported cases in New Mexico.
A person can have measles for four days before showing the telltale rash and is infectious during this time. If someone with measles goes to a school, grocery store, bank or any other public space, the air will be contaminated for up to two hours after the person leaves. Any unvaccinated person nearby has a 90% chance of becoming infected.
If your immune system hasn’t learned about the measles virus yet, it won’t matter how healthy your diet is. If you are exposed, you are likely to get measles.
That includes unimmunized schoolchildren. It also includes infants who are too young to be vaccinated, people who have compromised immune systems and the few people in whom the measles vaccine doesn’t prompt a full response from their immune system. When everyone else in a community is immunized, it protects these people, too.
Parents who are making decisions about their children’s health deserve honest answers about what we know, what we don’t know and what is false. Doctors who have treated children with measles know the limitations of current available treatments, and we know that a child would never choose to suffer from this disease. Pediatricians know that two doses of the vaccine are 97% effective at preventing measles, providing long-term immunity. It’s one of the most successful medical interventions in history and is estimated to have saved millions of lives. We do not have an antiviral medication approved for measles. Antibiotics do not work against measles because it is a virus. Parents who are making decisions about their children’s health deserve honest answers about what we know, what we don’t know and what is false. Vitamin A has been used as a treatment to help lessen symptoms in children who already have measles and who also have low levels of this micronutrient. In the U.S., vitamin A deficiency is extraordinarily rare. It is more common in low-resource countries, where children may have less access to foods rich in vitamin A, but global child health experts and the World Health Organization recommend vitamin A supplementation for all measles patients. U.S. pediatricians agree. To be clear: Vitamin A does not prevent measles. Cod-liver oil, which contains vitamins A and D, does not prevent measles. You also do not actually need high levels of vitamin A to be healthy. It is a micronutrient and children need relatively small amounts that they can easily consume through a healthy diet. Too much vitamin A can make a child very sick, and it is always wise to talk with your pediatrician before adding any supplement to your children’s diet. If you have questions about the measles vaccine, today is a good day to talk with your pediatrician or another doctor who knows you and knows your child. Ask all your questions. When my grandchild was born, my daughter and son-in-law came to me with many of these same concerns. We talked. I told them the same thing I told all my patients’ families: I would be devastated if your child became sick and I didn’t do absolutely everything in my power to protect them. The best way to help your children stay healthy is to vaccinate them. They agreed.
Dr. Susan J. Kressly
Susan J. Kressly is a doctor and the president of the American Academy of Pediatrics. 
