The percentage of U.S. students who started kindergarten last school year with evidence of being vaccinated against diseases like measles and polio has fallen for the second year in a row, the Centers for Disease Control and Prevention said Thursday.
In the 2021-2022 school year, an estimated 93% of the country’s nearly 4 million pre-school children received recommended vaccines to protect against measles, tetanus, polio and chickenpox.
That’s down from 94% in the 2020-2021 school year and 95% in the pre-pandemic 2019-2020 school year, according to figures released Thursday by the CDC based on data collected from state and local immunization programs.
“This means that almost 250,000 kindergartens are potentially unprotected against measles alone. And we know measles, mumps, and rubella immunization coverage for preschoolers is at its lowest in more than a decade,” Dr. Georgina Peacock, CDC division’s director of immunization, told reporters Thursday.
The decline did not come with a corresponding increase in parents obtaining non-medical exemptions from vaccination requirements, CDC officials said, suggesting that some children may still be able to catch their injections.
“Many of these children attend school under a policy considered to be a grace period or also known as provisional registration, which gives the family time to submit documents to school or, if the child is in the process of getting vaccines, giving them enough time to complete all vaccination series said Shannon Stokley of the CDC.
Some of the decline may also be a direct result of changes to schools themselves during the COVID-19 pandemic. Twenty-three states have told the CDC that they have incomplete school records, and some are late in reporting their records.
The agency estimates that all but four states could achieve 95% MMR coverage if those preschoolers without documented vaccines were vaccinated instead of getting a waiver.
The decline in vaccination coverage represents the latest setback for health officials who have worked to increase coverage among young children against several diseases that can be prevented by vaccinating before going to school.
For example, the United States had measles, mumps, rubella, or MMR vaccination rates close to or above 95% for several years prior to the pandemic, dropping to 93.5% nationwide.
“The reason why it’s important for children entering kindergarten to get the MMR vaccine is because we know that measles in particular is spreading very quickly, as you can see from the two outbreaks we had last year,” Peacock said.
The CDC reported 118 cases of measles nationwide last year, the most since the record-breaking outbreak in many states in 2019.
While the nationwide MMR vaccination rate among preschoolers has declined, trends vary greatly from state to state. Officials said some saw falls of more than 5 percentage points while others rose more than 6 percentage points. Nine states are currently below 90%:
Alaska = 78.0%
Wisconsin = 82.6%
Georgia = 83.2%
Idaho = 83.9%
Kentucky = 86.5%
Ohio = 88.3%
Colorado = 88.4%
New Hampshire = 88.7%
Minnesota = 89.0%
Health authorities have previously warned of a slowdown in vaccine procurement, suggesting missed follow-up trials during the pandemic may have led to a decline in younger children being vaccinated.
However, separate results from the CDC’s National Immunization Survey released Thursday for children in the first two years of life suggest that many of these young children still have their vaccines up to date compared to years past.
Around 70% of children born in 2018-2019 are up to date on the “combined” series of seven vaccines recommended for these youngest children, which range from diphtheria vaccines to pneumococcal infections.
“This report did not identify any overall decline in vaccination related to the COVID-19 pandemic among all children. The youngest children were born in 2019. These children reached the age of 12 months in 2020 and 24 months in 2021.” the authors wrote.
Some disparities have deepened during the pandemic. Vaccination has declined among both poor children and those living in rural areas. Coverage remains lowest among black children compared to other races.
A separate report published in November by the agency also warned of the possibility that COVID-19 could lead to a long-term decline in routine vaccinations.
This report warned of the risk that a myriad of factors, from weakening trust in institutions to state legislative efforts to weaken vaccination requirements, could undo years of progress in increasing routine vaccinations.
Peacock said the CDC is launching a new initiative to catch up with routine vaccinations in all age groups, in light of both recent measles outbreaks and last year’s discovery.
“These epidemics were preventable. The best way to prevent these diseases and their devastating effects on children is through vaccination,” said Peacock.