Eight persons have been affected thus far in a recent outbreak in Philadelphia.
Over the past 20 years, measles outbreaks have persisted in the US despite the availability of a very efficient vaccine.
As of December 2023, eight cases have been confirmed in Philadelphia; all of the cases were unvaccinated persons. Furthermore, local sources claim that a measles case has been found in Delaware, New Jersey, and Washington state, and that the patient passed through airports in the D.C. area.
Based on available but insufficient data from the Centers for Disease Control and Prevention (CDC), there were 41 confirmed cases of measles in 2023.
Health experts and officials are concerned about the trend of outbreaks persisting even while the number of measles infections in 2023 is lower than in previous years and has not reached record highs in recent years.
In 2000, the disease was deemed eradicated, indicating that it "is no longer constantly present in this country." However, outbreaks have been brought on by travelers bringing measles into the nation and a decline in normal kid immunizations in recent years.
"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," Dr. Peter Hotez, 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, told ABC News.
Lagging vaccination rates
A CDC report in November found that exemptions for routine childhood vaccination among U.S. kindergartners are at their highest levels ever.
According to the CDC report, during the 2022–2023 school year, around 93% of kindergarten students received certain routine childhood vaccinations, such as the measles, mumps, and rubella (MMR) vaccine, which provides measles protection.
While this is comparable to the previous school year, it is less than the 94% observed in the 2020–21 academic year and the 95% observed in the 2019–20 academic year, which preceded the COVID-19 epidemic. For almost a decade, the latter percentage had been considered the norm.
According to Hotez, there can be regions in the US with greater percentages of vaccination exemptions for both legitimate and non-legitimate grounds.
"For instance, when we studied this in 2018, looking at the states that allow vaccine exemptions for non-medical reasons, we would find counties that maybe 10 to 20% of the kids were not getting their childhood immunizations and that's what measles exploits," Hotez continued. "So, if were uniformly 93%, it's not ideal, but probably that wouldn't be enough to stimulate measles outbreaks."
Approximately one in five Americans who contract the measles will require hospitalization. According to the CDC, measles can result in ear infections, diarrhea, pneumonia, encephalitis (brain swelling), and even death, especially in children under the age of five.
In 1963, the United States introduced the first measles vaccination, which was a single-dose shot. Three to four million instances a year resulted in 48,000 hospital admissions and 400–500 deaths in the ten years previous.
The CDC recommends that people get two doses with the first dose at 12 to 15 months old and the second dose between ages 4 and 6. Two doses are 97% effective, while one dosage is 93% effective.
Hospital admissions and fatalities have sharply decreased since then. There were three deaths in the Americas in 2000 and just one in 2022, according to a November 2023 CDC report.
"We can prevent this, we can stop this. Parents should be scared of measles," Dr. Paul Offit, director of the Vaccine Education Center and an attending physician in the division of infectious diseases at Children's Hospital of Philadelphia, told ABC News. "They should be scared of this virus as my parents were. The difference was [my parents] couldn't do anything about it."
"Now you can do something about it, which makes it all the more unconscionable when you see children come into our hospital who could have gotten vaccinated and didn't," he said.
An increase in false information about vaccines
Experts have identified a few causes for the decline in immunization rates. One is Andrew Wakefield's 1998 study in The Lancet, which asserts that autism was caused by the MMR vaccination. Though suspicions persist, the report has subsequently been refuted, further research has found no connection, and the journal has withdrawn the paper.
During an outbreak in Columbus, Ohio that lasted from November 2022 to February 2023, public health officials said many parents of the unvaccinated children infected with measles had chosen not to have their kids receive the MMR shot due to misconceptions that it causes autism.
"Ever since that Anfrew Wakefield article, people have developed important misconceptions from that misinformation and continuing disinformation about the MMR vaccine," Dr. Gregory Poland, head of the Mayo Clinic's Vaccine Research Group, told ABC News. "He claimed there was an association with autism. Some 24 studies have subsequently found none. Not one indicate a hint of autism risk."
"Once you scare people, it's hard to unscare them, so people then then sort of started to back away from that vaccine," Offit said. "So we saw cases again."
According to experts, the COVID pandemic led to another issue, First off, people were afraid to see doctors in the early stages of the epidemic, which caused a delay in youngsters receiving their recommended dose of immunizations.
It's not limited to the United States. Global cases of measles have been on the rise in recent years, increasing 18% from 2021 to 2022, following a drop in vaccinations over the past few years, according to a report from the WHO and CDC released last year.
The general public's belief in immunization may have declined as a result of the politicization of COVID vaccinations.
There's been "an acceleration of anti-vaccine sentiments that we've seen during the COVID 19 pandemic," said Hotez. "And I think what we may be seeing also was a spillover that extended beyond COVID vaccines to all childhood immunizations."
"This increase in cases serves as a reminder of the persistent difficulties in overcoming vaccine hesitancy and the necessity of preserving high immunization rates in order to develop herd immunity. To ensure that our public health infrastructure is strong enough to handle such outbreaks, we need to work together to address these concerns," said Dr. John Brownstein, an epidemiologist, chief innovation officer at Boston Children's Hospital, and contributor to ABC News.
Experts speculate that individuals may have forgotten how serious the diseases were before vaccinations because vaccinations have made them less common. This could be another factor contributing to the drop in immunization rates.