A recent federal effort to scale back the routine childhood vaccine schedule has shaped how families approach immunization, according to physicians and researchers at Penn Medicine and the Children’s Hospital of Philadelphia.
The proposal — introduced in January by Health and Human Services Secretary Robert Kennedy Jr. — sought to reduce the standard pediatric immunization schedule from 17 recommended vaccines to 11. Although a federal judge blocked the change last month, clinicians at Penn and CHOP told The Daily Pennsylvanian that the debate contributed to a national wave of vaccine distrust.
In the last six years, CHOP’s Primary Care Network has seen a decrease in the percentage of children up to date on immunizations at age 2, according to Joseph St. Geme, the hospital’s physician-in-chief.
St. Geme wrote that “the percentage was 80.0% in 2020 and has dropped to 73.0% in 2026.”
“Most interactions continue to be very positive, very constructive — recognizing the shared goal by the pediatrician and parent for that child to be healthy and have a bright future,” he added in an interview with the DP. “But there’s a growing number of parents who do have concerns.”
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CHOP Vaccine Education Center Director Paul Offit — who teaches pediatrics at the Perelman School of Medicine — said that patients often become “less compelled by the fear of disease” because vaccines have made those diseases less visible.
“When I talk to people, I say early on, ‘is there anything that I can say that will change your mind?’” Offit explained. “If there’s not, then we don’t really need to have this conversation.”
Some families “are just absolutely not going to move” on their vaccine reluctance, CHOP infectious disease physician Lori Handy told the DP, adding that skepticism often emerges as a result of politics, religion, social circumstances, or distrust in the pharmaceutical industry.
Handy stated that vaccine mandates during the COVID-19 pandemic contributed to “significant growth of the medical freedom movement,” including those who were hesitant to accept the vaccine.
CHOP primary care physician Katie Lockwood similarly described a shift within the public’s vaccine attitudes in a statement to the DP.
“Some parents who previously vaccinated their children have halted giving additional vaccines or after having a new baby, decided not to vaccinate at all,” Lockwood wrote.
Perelman School of Medicine professor and Leonard Davis Institute fellow Angela Shen conducts research on how the COVID-19 vaccine affected routine immunizations.
“A lot of decisions parents made for their kids were different than the decisions that they made for themselves,” Shen said of the pandemic. She also highlighted that ongoing legislative debate regarding vaccinations is “injecting doubt in parents.”
Offit said that it is “perfectly reasonable” for parents to ask questions about vaccines.
“We do ask a lot from parents,” he said. “We ask them, in the first few years of life, to prevent 14 different diseases, which can mean as many as 25 inoculations during that time.”
In 2025, the U.S. hit its highest rate of measles cases in over 30 years, jumping from 59 reported cases in 2023 to 2,287 in 2025.
“If you see lots of measles outbreaks, it tells you that there’s something up with the system,” Shen told the DP. “You see measles first because it’s the most infectious. It spreads much easier, and so we call that the canary in the coal mine.”
Looking forward, CHOP infectious disease physician Maulin Soneji predicts that clinics will need to increasingly test children with certain symptoms for diseases that have vaccines.
He explained that vaccine uptake improvements in recent years have reduced the need for invasive procedures like lumbar punctures, which involve taking fluid from the spine to test for illnesses like meningitis for children with fevers.
When the 2026 updated vaccine schedule was first proposed, Soneji recalled thinking that children and families would “suffer needlessly” from such testing.
“I think we’re going to be doing more of these procedures and more of these workups, especially on unvaccinated children,” Soneji said.
Staff reporter Addison Saji covers Penn Medicine and can be reached at saji@thedp.com At Penn, she studies English. Follow her on X at @addisonsaji.