February 23, 2024 – The recent rise in measles cases within the United States and worldwide is linked to declining childhood vaccination rates, medical examiners say.
The CDC issued one alarm Last month it said 23 confirmed cases of measles had been detected within the United States between December 1, 2023 and January 23. These include seven cases brought in by international travelers and two outbreaks with greater than five cases each.
“Most of these cases involved children and adolescents who had not received measles vaccine (MMR or MMRV), even if age-appropriate,” the CDC said.
Vaccination rates have been declining for several years.
According to the CDC, national coverage for measles, mumps and rubella (MMR) was 93.1% within the 2022-2023 school yr, a 2% decrease from the 95% rate within the 2019-2020 school yr reported. This was the third yr in a row that the speed fell below 95%, the extent required for herd immunity.
“We're not just seeing cases, we're seeing transmissions, which means vaccination rates are not where we would like,” Saskia Popescu, PhD, assistant professor of epidemiology and public health on the University of Maryland School of Medicine, tells PBS.
Another expert said increased vaccine hesitancy in the course of the pandemic has also affected measles vaccination rates.
“In addition, as children were quarantined during the pandemic, many missed their children's visits and did not catch up on their vaccinations. This meant that 61 million fewer vaccine doses were distributed nationwide between 2020 and 2022.” said Priya Soni, MD, pediatric infectious disease specialist at Cedars-Sinai Guerin Children's.
The same trends are occurring worldwide. From 2021 to 2022, global measles cases rose 18% and deaths rose 43%, in line with the CDC and the World Health Organization reported.
“The increase in measles outbreaks and deaths is alarming, but unfortunately not unexpected given the declining vaccination rates we have experienced in recent years.” said John Vertefeuille, PhD, director of the CDC's Global Immunization Division.
“Measles cases everywhere pose a risk to all countries and communities where people are not adequately vaccinated. Urgent, targeted efforts are critical to preventing measles illnesses and deaths.”