Measles outbreaks expand
In the year 2000, the United States declared that it had eliminated measles, thanks to the highly effective two-dose vaccine for children. However, over the last 18 months, the Centers for Disease Control and Prevention reported a total of 4,459 cases, with outbreaks in several states, most notably South Carolina, Texas, and Utah.
During the recent briefing organized by the ACoM on the resurgence of measles in the US, experts discussed how the virus remains highly contagious and dangerous, with risks including pneumonia, severe dehydration, immune suppression, and even death. The infection is fatal in about three of every 1,000 cases, and increasingly, adults over the age of 20 are reporting measles. Utah has faced a year-long measles outbreak. But fewer than 84% of children there have received both doses of the MMR vaccine, which protects against measles, mumps, and rubella.
In the Somali community in Minnesota, which has had a measles outbreak in 2024, only one in four children received their first MMR shot by age two.
Community vaccine coverage below threshold
According to Patsy Stinchfield, pediatric nurse practitioner and executive director of the Measles Collaborative, when vaccination coverage drops, even by a few percentage points below the threshold needed for community protection, measles spreads rapidly.
“The virus is the same as it has been. It came back because we let our guard down. And because measles circulates globally and importation is a constant risk, we’ve got to keep our vaccine rates up,” Stinchfield said.
The community requires 95% vaccination coverage to prevent the spread of the virus.
How does measles spread?
Measles is a highly contagious virus that spreads when an infected person coughs or sneezes. Once in the system, it replicates quietly and can affect the lungs, causing pneumonia, or the gut, causing severe diarrhea and dehydration. It can affect even the brain, affect vision and hearing, and in rare cases, can cause death. The most common symptoms are high fever, runny nose, rash, pink eye, loss of appetite, lethargy, and an impact on the immune system that may take years to recover.
Talking about the efficacy of the vaccine against the current strain, Dr Benjamin Neuman, professor of biology, Texas A&M University, said that the current vaccine strain, which has low side effects, is very effective against the two strains circulating at the moment, which are B3 (in other countries) and D8 (mostly in the US).
“I think people are used to thinking about influenza and COVID, viruses which mutate rapidly and manage to escape our immune system, and escape the effects of our existing vaccines. Measles is very different. Measles infection gives you immunity that lasts pretty much lifelong, so it’s much better at creating immunity. And the parts of measles virus that generate that immune response have changed very little since the virus was first isolated in the 50s,” Dr Neuman said.
Health officials fight vaccine misinformation
One of the key highlights of the briefing was the importance of combating vaccine misinformation circulating in the Somali community in Minnesota, where parents delay vaccinating their children until age 5. This is because they have been wrongly told that the MMR vaccine causes autism. Then some did not vaccinate their children because they thought the virus was gone from the US, noted Stinchfield.
To address such misinformation and misunderstanding, she said that they arranged meetings, community gatherings and talked to the imams, the very people anti-vaccine groups went to, and addressed their fears and talked about the dangers of the disease.
“But the reasons that we cannot achieve high vaccination rates are very complex and require numerous and diverse interventions,” she added.
Experts also weighed in on Utah’s year-long outbreaks caused by low vaccination rates in some pockets of the state, mainly due to a lack of trust in the government and public health authorities. In the last 12 months, the state has reported 704 cases, which the experts believe is an undercount, and the actual numbers may be higher than reported.
Addressing the rising infection rates in adults over 20, Dr Andrew Pavia, professor and chief, Division of Pediatric Infectious Diseases at the University of Utah, said that about a one-fourth of all the measles cases have been identified in adults. He added that people over 20 and children younger than five are more likely to get severely ill with measles, be hospitalized, and have complications. As of last week, he noted over 50 hospitalizations, between young children and adults.
Measles is also a big threat to pregnant women as the virus can severely infect them and can also transmit the virus to their infant if they have been infected with measles in the last 14 days of their pregnancy.
“In Ontario, three infants died because their mothers had measles just prior to delivery. In Utah, we had 12 pregnant women who developed measles close to delivery. We were lucky. The children of these mothers all survived and did well. But that’s only a matter of luck. The next time it could turn out much worse. So for women who are considering pregnancy, being immune to measles is absolutely critical. You can’t get the vaccine when you’re pregnant. So you have to know whether you need it before you decide to become pregnant. And that’s something that we need to really emphasize,” said Dr Pavia.
The newer ACIP committee under Robert F. Kennedy
The CDC Advisory Committee on Immunization Practices (ACIP) has undergone a significant transformation since the appointment of secretary, Robert F Kennedy Jr. Speaking on the differences, Dr Jose Romero, former health secretary of Arkansas, and former chair of the CDC’s ACIP, said that traditionally, the committee members were selected through a rigorous process involving nominations, conflict of interest disclosures, and review for expertise and diversity. The panel was assembled to reflect the American public and is internationally respected for its methodical evaluation of vaccine recommendations, using thorough data analysis and stakeholder engagement.
However, now, the committee members are directly chosen by the secretary, bypassing the established procedures, which undermines the committee’s diversity and rigor, and the recent decisions, such as the one on the Hepatitis B vaccine, lacked the robust debate and transparency that previously defined the ACIP process, observed Dr Romero.
Long-term effects of measles
Like the chickenpox virus, which can later cause shingles, there are also concerns about the long-term effects of measles. Dr. Pavia explained that a particularly severe outcome is SSPE (Subacute Sclerosing Panencephalitis), a rare but fatal neurological condition. Fortunately, SSPE can be easily prevented with two doses of the MMR vaccine. The speakers unanimously agreed that getting the vaccination is the safest option to limit the spread of the virus and advised people to get vaccinated, especially when travelling.
