- As the measles outbreak expands across the United States, public health measures have increased to slow the spread of the disease.
- Many people have expressed worries about whether vitamin A can help prevent infection, whether they need a measles vaccine booster, or if measles can have long-term negative consequences on health.
- The latest question to fuel concern has been about how long the protection of the measles vaccine lasts, driven by U.S. Secretary of Health and Human Services Robert F. Kennedy Jr.’s recent comments.
- Medical News Today speaks to experts to fact-check some prominent claims about measles and the MMR vaccine.
United States Secretary of Health and Human Services RFK Jr. recently joined other experts and expert medical bodies in endorsing the MMR (measles, mumps and rubella) vaccine as the most effective way to ensure protection against measles.
His comments came in an X post in what many people described as a surprise due to his past skepticism toward vaccine safety and effectiveness.
However, shortly after he shared this message, the secretary was interviewed on CBS News, where he alluded to ebbing immunity from vaccines and other ways to treat people who choose not to get vaccinated.
“We’re always going to have measles, no matter what happens, as the vaccine wanes very quickly,” Kennedy had said.
So far, there are no other preventive treatments against measles other than the MMR vaccine. Vitamin A, for example, is also only given to lessen the severity of symptoms after a person has contracted measles.
Many medical professionals and the public have been left confused and worried about these comments. To fact-check these claims, Medical News Today spoke to two experts: David Cutler, MD, board certified family medicine physician at Providence Saint John’s Health Center in Santa Monica, CA, and Gina Posner, MD, board certified pediatrician at MemorialCare Medical Group in Fountain Valley, CA.
Cutler said:
“It is both disappointing and dangerous that there is so much conflicting and incorrect information from the current U.S. Secretary of Health and Human Services regarding measles and the MMR vaccine. Part of the problem is that infectious diseases, immunity and vaccines are all complicated. But there is also the problem of misleading and absolutely false information coming from a previously trusted government source. So, what is true?”
Fact: Two doses of the MMR measles vaccine provide lifetime protection.
Referring to RFK Jr.’s recent comments, Posner said it wasn’t true that the vaccine’s protection waned quickly.
“Most people get the vaccine as young kids (age 1 and 4) and have it lifelong,” she said.
Cutler said that in the case of the MMR vaccine for measles, the immunity provided by the innoculation will last a lifetime. However, he reminded of exceptions when it comes to two other infections.
“Sometimes, viruses will change, so the immunity you get from the vaccine may not protect you against future variants of the virus; this is true for influenza and COVID. But the measles virus has been unchanged for centuries,” he said.
Is the measles vaccine safe and effective?
Cutler reiterated that measles was eradicated in the U.S.
“However, because there are rare side effects and a very small percentage of people who do not achieve full immunity after vaccination, it is possible that some people will weaponize this uncertainty to claim the danger and ineffectiveness of the MMR vaccine,” he added.
“In general, a single dose of the MMR vaccine is
“However, a single vaccine is adequate for adults who have not been previously vaccinated. The value of the second vaccine depends on your individual risk and how much measles is out there,” he added.
Why herd immunity is crucial
Posner reiterated that 97% of people get full immunity after the second dose of the vaccine.
“That still does leave 3% as non-responders which is why we need herd immunity to protect both those people and ones who really can’t have it,” she said.
Cutler underscored the importance of public health and said that for measles spread to be unlikely, approximately
“Epidemiologists estimate that if 95% of people in a community are vaccinated, then there will not be enough susceptible people to prolong an outbreak. In addition to vaccines, isolating [people with infections] will help prevent the spread of the disease,” he said.
Fact check: False, for the majority of people. If you have received two doses of the MMR vaccine, you will have lifelong protection. However,
“Some people get tested for immunity later in life (like pregnant people) and if they are found not to have immunity, once they give birth, they are told to get another dose (or two),” Posner added to highlight exceptions.
“If [a] virus mutates, then a different strain needs to be given with a new vaccine. Also, sometimes we don’t develop as strong of an immune reaction to a certain vaccine and then we must repeat it every so often (like our Tdap needing to be done every 10 years). MMR is not one of those. It is given at age 1 and 4 typically and that is it.”
— Gina Posner, MD
Cutler said some infectious diseases may require boosters periodically but that measles was not one of them.
“Another reason you may need a booster vaccine is if your immunity wanes with time. This is true for tetanus shots. That is why tetanus boosters are recommended every 10 years. But this is not true for measles. Once immune from either the vaccine or prior infection, your measles immunity persists,” he said.
Fact check: The only tested and effective way a person can protect themselves against measles is via the MMR vaccine. There are no other effective preventive treatments for measles. However, vitamin A can be used to lessen the severity of disease in people who are already experiencing a measles infection.
“Severe cases of measles can be treated with two doses of vitamin A to prevent complications of the disease. However, the risks of high doses of vitamin A need to be considered prior to initiating this therapy. There is no evidence that vitamin A or any dietary supplement prevents acquiring measles infection,” Cutler said.
“The true value of the vaccine can only be achieved when very high percentages of people are vaccinated, even when disease risk is low. People acting in their own self-interest by avoiding vaccines puts us all at greater risk. Adequate funding, staffing, and resourcing of public health efforts are essential for disseminating accurate information and providing services to protect everyone from diseases like measles.”
— David Cutler, MD