“We’re talking about a lot of children who are dying from measles every year from a disease that’s entirely preventable”
Natasha Crowcroft, MD, PhD, World Health Organization senior technical advisor for measles and rubella
“Measles vaccine has saved more lives than any other vaccine in the past 50 years.”
Tedros Adhanon Ghebreyesus, PhD, World Health Organization Director General
Measles is caused by a highly contagious, airborne virus. It is, however, a disease that can be prevented by a safe and effective vaccine. Nonetheless, according to the World Health Organization (WHO), in 2023, there were an estimated 10.3 million cases of measles worldwide—a 20% increase from 2022—and 107,500 deaths from measles, mostly in children under age five. (See, “Measles cases surge worldwide, infecting 10.3 million people in 2023,” Centers for Disease Control and Prevention Media Relations, November 14, 2024; see also, “Measles is Back: Why?,” Germ Gems, February 7, 2024). And, this situation is going from bad to worse. In this week’s post, I refresh your memory about this nasty virus and provide an update on this ancient disease—first described in the 9th century by the Persian physician and scholar Razi—that at one time was in the crosshairs of eradication.
Measles (a recap). Measles virus is an airborne pathogen and is one of the most contagious infectious agents. Also known as rubeola, measles can affect anyone, but is mainly a disease of children.
Signs and symptoms of the disease usually begin 10–14 days after exposure to the virus. Early symptoms usually last 4–7 days. While a prominent rash is the most visible symptom, other symptoms include:
running nose
cough
red and watery eyes
small white spots (called Koplick spots) inside the cheeks.
Common complications of the disease include otitis media, pneumonia, and diarrhea. A variety of neurological disorders can also occur, including seizures that generally develop 7 to 10 years after infection. People at high risk for complications from measles include infants and children less than 5 years, adults over 20 years, pregnant women, and immunocompromised patients.
Measles is a preventable disease. In 1954, John Enders and Thomas Peebles isolated the measles virus (an RNA virus) from the blood of a 13-year-old student named David Edmonston. In 1963, the first live attenuated measles vaccine, the Edmonston B strain, was licensed for use in the U.S., and in 1971, the combined measles, mumps, and rubella vaccine was licensed.
Measles vaccine is one of the most effective of all vaccines, and it serves as the backbone of measles prevention. Before the introduction of measles vaccine and widespread vaccination, major measles epidemics occurred about every two to three years killing an estimated 2.6 million people each year.
There remains no specific treatment of measles. Therefore, maintaining a high level of vaccination across the globe is crucial in controlling the disease. Because of widespread employment of vaccines, by the end of 2023, 82 (42%) countries had been verified to have achieved or maintained measles elimination—defined as the absence of locally transmitted infections or outbreaks for at least 12 months in a specific geographic area. But no WHO region had achieved and sustained elimination, and no African country had yet been verified to have eliminated measles.
Measles importation by unvaccinated people who were infected while traveling in other countries remains a major challenge in controlling and ultimately eliminating the disease. Hence, it is critical for all international travelers to be vaccinated against measles.
The reason for the 20% increase in measles cases in 2023 can be attributed to poor vaccination. The disruption in vaccination programs can be blamed in part on the chaos created by the COVID-19 pandemic. But an increase in vaccine skepticism is playing an increasingly important role.
Correlation doesn’t mean causation. The President-elect’s nomination of Robert F. Kenney Jr. to run the Department of Health and Human Services has sent deep concerns throughout all health institutions in America. (See, “Will Trust in Science Continue to Improve?”, Germ Gems December 11, 2024). Mr. Kennedy, who has no background in health, science or medicine, is an established spokesperson for the antivaxx movement in America and has made and continues to make unsubstantiated claims that the measles vaccine causes autism. Every credible public health institution in the U.S. and abroad has debunked this claim.
To sum up the consensus view of public health experts: there is no tenable evidence that measles vaccine causes autism. Yet, Mr. Kennedy persists.
It appears that Kennedy is a victim of “the correlation not causation” fallacy. It also appears that the President-elect may have also fallen victim to this fallacy. In a December 12, 2024 interview, the President-elect was asked about Mr. Kennedy’s opinion on the vaccine/autism matter and stated: “something must be causing the increase in autism.”
Something may indeed be causing the increase in autism. But I suggest there are other more convincing putative links (correlations) to investigate than the measles vaccine. Air pollution is an example. A meta-analysis from the Harvard T.H. Chan School of Public Health published in Environmental Research Letters in 2021 found: “Exposure to fine particulate air pollution (PM2.5) has been linked with significantly increased risk of autism spectrum disorder (ASD) in children, particularly if exposure occurs during the third trimester of pregnancy or during early childhood.”
But no one knows why autism is on the rise or what causes it. What we do know is that measles, a sometimes deadly and often debilitating disease, is preventable with two doses of a the highly effective measles vaccine. (One dose is 93% effective; two doses are 97% effective.) There is highly tenable evidence that the measles vaccine saves lives but there is no tenable evidence that the measles vaccine causes autism. This point cannot be emphasized enough.
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