Measles cases are popping up in several US states

Although measles was declared to be eliminated in the United States in 2000, a decline in childhood vaccinations and travelers bringing the virus into the country has caused sporadic outbreaks to occur. In 2023, there were 56 reported measles cases.

In recent years, the number of measles cases in the United States have been relatively low, but health officials and experts are still concerned about the outbreaks occur.  

As of Jan. 16, Philadelphia's health department has confirmed nine cases of measles, which spread from local health facilities and a daycare. At least three cases were in unvaccinated children.

In Washington state, there have been three lab-confirmed cases and three epidemiologically linked cases among unvaccinated adults. Both New Jersey and Missouri have also each confirmed a case of measles.

In Delaware, 20 to 30 people were exposed to measles at Nemours Children's Hospital. Virginia health officials also flagged a case where someone may have exposed the measles to people at Dulles International Airport and Ronald Reagan Washington National Airport.

"The fact that we're seeing sporadic measles cases, to me, says that we probably have pockets in the United States where we're not doing a good job vaccinating and I'm worried that this is a trend that's been getting worse over the years," said Peter Hotez, a professor of pediatrics and molecular virology at Baylor College of Medicine, dean of the National School of Tropical Medicine, and co-director of the Texas Children's Hospital Center for Vaccine Development.

Measles cases have also increased globally, with a report from the World Health Organization and CDC finding an 18% increase in cases from 2021 to 2022. "Measles is coming back, and with that there's more chance of importation into the United States," said Walter Orenstein, from Emory University School of Medicine.

Lagging vaccination rates are likely behind the sporadic outbreaks

According to health experts, the recent outbreaks of measles may be in part due to fallout from the COVID-19 pandemic. During the height of the pandemic, rates of routine vaccinations decreased while vaccine hesitancy increased.

"The ones that are getting measles are those that are simply not vaccinated, for whatever reason, whether it's mistrust of the public healthcare system, [or] maybe they're having eroding confidence in their healthcare providers," said Steven Schweon, a member of the Emerging Infectious Diseases task force for the Association for Professionals in Infection Control and Epidemiology. "They may believe misinformation that's out there, as opposed to credible information."

There has been "an acceleration of anti-vaccine sentiments that we've seen during the COVID 19 pandemic," Hotez said, "And I think what we may be seeing also was a spillover that extended beyond COVID vaccines to all childhood immunizations."

Although most people recover from a measles infection, it can lead to serious health complications, including hearing loss, pneumonia, encephalitis, and even death. Children are also highly susceptible to measles, and the virus is highly infectious, more than COVID-19 or the flu.

To reduce the risk of infection, Schweon recommends healthcare providers ask if patients have been vaccinated, and if they haven't, vaccinate them as soon as possible. Currently, CDC recommends people get two doses of the measles vaccine, with the first dose at 12 to 15 months and the second dose between the ages 4 and 6. One dose is 93% effective against measles while two doses is 97% effective.

"Healthcare providers should be asking [patients] about their vaccine history, if they are up to speed with their vaccines," Schweon said, "and if their patients aren't sure, depending on the vaccine and why, it's a great opportunity to vaccinate them right there in the office."

Separately, Orenstein said healthcare providers should prioritize building trust with their patients to address any potential concerns and overcome vaccine hesitancy.

"It's important to try and explain that getting the measles vaccine is your protection -- and protects them from diseases -- that will prevent hospitalizations, pneumonia, ear infections and even encephalitis or brain damage," he said. "So we need to get that message across, and we need to find the right messengers." (Kekatos/Benadjaoud, ABC News, 1/18; Putka, MedPage Today, 1/18; CDC measles data, accessed 1/19)

In the wake of the COVID-19 pandemic, jurisdictions are re-evaluating the role and strength of their public health institutions. Advisory Board's Isis Monteiro examines Brazil's public health system and how its track record of running successful immunization campaigns have promoted "cultural faith" in vaccines.