The 2021-22 school year marked the second time in a row the U.S. fell below a goal of vaccinating 95% of children entering kindergarten against measles, mumps, and rubella, the Centers for Disease Control and Prevention said this week.
Vaccinations dropped to 93% last year, compared to 94% the year before. The 2019-20 school year was the last time the U.S. hit its goal of reaching 95%. The reason for the 95% goal is the CDC considers a vaccination rate of 95% the threshold for herd immunity for measles.
According to the Centers for Disease Control and Prevention, the measles vaccine is about 97% effective. For the small percentage of those fully vaccinated who get infected, the CDC said measles cases tend to be mild.
The virus initially causes a high fever, runny nose, cough and watery eyes. It can then cause spots and rashes.
About 2.6% of children received an exemption from the vaccines. Each state has its own criteria for exemptions, but all 50 states allow exemptions for medical purposes, according to the CDC.
An additional 3.9% of children entering kindergarten who were not up to date on their vaccines did not have an exemption.
The CDC said that “pockets of undervaccinated children within larger areas of high vaccination coverage can lead to outbreaks.”
“High vaccination coverage is critical to continue protecting children and communities from vaccine-preventable disease,” the CDC said.
The CDC recommends schools continue to follow up with unvaccinated students.