Chester County high school closed Friday due to confirmed measles case

In the latest sign of the concern over a Pennsylvania measles outbreak that is now the nation’s largest, Oxford Area High School was closed on Friday due to a confirmed measles case.

Districts in other outbreak areas have not been closing schools as the state grapples with its worst measles outbreak in three decades, but school officials in the Chester County community west of Philadelphia made the decision after consulting with county health officials to limit the risk from the highly contagious disease.

In a letter to the school community, Oxford Area School District Superintendent David Woods said that all students and staff who are unvaccinated, or do not have proof of their vaccination status, will be required to quarantine at home for 21 days. The school’s quarantine decision follows Pennsylvania Department of Health guidelines.

Schools are required by state law to track and report data for all required vaccines — including the measles, mumps and rubella (MMR) vaccine — for students but not for staff.

Chester County’s health department directed the school to verify the vaccination status of its employees, Woods said in the letter. The district made the decision to close the school Oct. 9 to complete the verification process, a county spokesperson said.

School and county officials have not said whether the positive case involved a student, staff member, or someone else in the school community. “We recognize that situations such as this can be unsettling, especially when they involve the health of children,” Woods said in his letter.

High school and district officials did not respond to a request for comment.

The superintendent’s note did not say whether the school will reopen Monday or whether homecoming festivities planned for this weekend would be canceled.

But the school district did decide that a football game, with Oxford playing at Kennett High School in Kennett Square, could go on “after taking the appropriate health and safety precautions,” officials said in a social media post.

Pennsylvania Department of Health “generally does not recommend school closure for outbreaks of infectious diseases” as an initial response, according to published school guidance. Exposed students and staff who are unvaccinated or cannot verify their vaccination status will be instructed to stay home for 21 days, according to a health department spokesperson.

The decision to close is ultimately made by school administrators, according to the Department of Health, which urges schools to consult with in-house medical staff and county or state health authorities.

Chester County Health Director Jeanne Franklin applauded the district’s quick response, noting the move could prevent longer closures from widespread sickness.

“We don’t want it to get to the point of they have to shut down because they don’t have the staff to run the school, or too many students are infected and can’t come to school,” she said.

The county learned of the case from a health provider who treated the individual, and then contacted the school district.

Vaccine records for students were readily available, but the school was still in the process of gathering vaccine information about staff — a step the county had urged schools to take in anticipation of the region’s outbreak reaching Chester County schools.

The district ultimately decided it did not know the vaccination status of enough of the school’s employees to safely open the school on Friday.

“The moment we called, they were on it,” Franklin said, adding that she “fully respected” the decision to close. As the first school in Chester County with a confirmed measles case, ”they’re going to have an abundance of caution and make sure they get it right,” she said.

Chester County has the third-most measles cases in Pennsylvania, despite an overall measles vaccination rate just below the 95% protection scientists say is necessary to prevent the virus from spreading.

Pennsylvania’s measles outbreak, largest in the nation this year, has sickened more than 1,100 people across more than half of the state’s counties. The state has confirmed five measles-associated deaths, the most seen in the nation in more than three decades.

The state’s outbreak, which began in April, is centered in Lancaster County, right outside the Philadelphia region.

Chester County is the only county in the Philadelphia region in which the virus is known to be actively circulating. The county has reported 87 cases this year, as of Friday, mostly along Chester County’s western border with Lancaster County.

Oxford is located in the southwestern corner of Chester County.

» READ MORE: Chester County has more measles cases than most entire states in the country

Another school in nearby West Grove, Technical College High School (TCHS) Pennock’s Bridge Campus, operated virtually on Friday, after the Chester County health officials notified its administrators of possible measles exposures between Sept. 30 and Oct. 2.

A spokesperson for the campus overseen by the Chester County Intermediate Unit said the decision was made “because the staff verification process could not be completed within the time frame required by the Health Department.”

Programs housed within its building, including the Practical Nursing Program and Early Discovery Center, were closed for the day.

Additionally, the county on Friday warned of possible measles exposures at multiple pharmacies Oct. 4:

Joe Maida, who is raising his 5-year-old granddaughter with his wife in East Nottingham, was surprised to hear the high school was shutting down for the day.

Maida, 65, felt there was a lack of information from the district to explain its decision — such as who in the school population was infected, if officials were disinfecting, if there was an adequate “plan of attack” to reopen Monday.

He was also surprised the high school’s varsity football team would be able to play a game Friday night.

“I’m a bit taken aback” by the response, he said.

But his granddaughter is vaccinated, and her elementary school was unaffected. “I’m not giving it a lot of energy,” he said. “It’s the measles. It’s not the plague,” he said.

Chester County reported its first measles case of the outbreak at the end of June. As part of its early preparations, the county health department alerted schools before the beginning of the new school year that they would need to know the vaccine status of all staff and volunteers in the event of a positive case.

While Chester County has an overall kindergarten measles vaccination rate just below the 95% herd immunity rate, Oxford Area High School students appear well protected.

The school reported that all of its 303 12th graders had received the MMR vaccine in the 2025-2026 school year, the most recent year for which data is available.

The district’s middle school, Penn’s Grove School, reported a 96.3% MMR vaccine rate among 7th graders last year.

» READ MORE: More Philly-area classrooms are seeing lower measles vaccination rates. How protected is your school?

To better understand how school districts have been preparing for possible measles cases, The Inquirer contacted 12 Chester County districts last month, asking how they were planning and communicating with students and staff about the prospect of quarantines.

The Oxford district, which has more than 3,000 students, did not respond, along with a number of other Chester County districts.

Pennsylvania State Education Association, the statewide teachers’ union, declined to comment on the school closure.

Oxford Area Education Association, which represents teachers at the high school, couldn’t immediately be reached for comment.

Measles, long considered eradicated in the United States, is resurging amid declining vaccination rates.

In the Philadelphia region, at least 40% of kindergartens were vulnerable to an outbreak as of last school year, up from 33% the prior year, according to an Inquirer analysis of school immunization data widely used to assess community protection levels.

Schools are required to report vaccine information for students in kindergarten, 7th grade, and 12th grade. Earlier this year, Pennsylvania’s Department of Health began making this information publicly available through a searchable database, in an effort to raise awareness of declining vaccine rates in schools.

Health officials in neighboring Delaware and Montgomery Counties said they have similarly been advising school districts about rules for unvaccinated students and staff in the event of a positive measles case.

Montgomery County has urged schools to review immunization records and confirm proof of immunity, and develop plans to “rapidly identify students and staff who may be at risk,” said Christina Miller, administrator of the county’s Office of Public Health.

Delaware County’s health department said that it would offer guidance to a school with a positive measles case on how to verify immune status for students, employees, and volunteers, as well as how to identify high- or low-risk exposures at the school.

If a case is identified in a Philadelphia school, the city’s health department said it would work with the school’s administration to determine when the person was infectious and how to protect exposed students and staff.

Counties without a local health department rely on Pennsylvania’s Department of Health.

Neil Ruhland, a spokesperson for the state health department, said school nurses or school leaders should contact the health department immediately if a measles exposure occurs at a school.

Schools should review attendance records, assess where the exposure occurred, and determine the vaccination status of exposed people.

If the department confirms a measles case and exposure at a school, it will notify families and provide guidance on what to do if they’re not vaccinated, Ruhland said. Exposed students who are vaccinated are considered immune and don’t need to do anything else.

An exposed person who isn’t fully vaccinated will be told to quarantine at home for 21 days, whether or not they show symptoms, Ruhland said. But, if that person gets an MMR dose within 72 hours of the exposure, quarantine will be lifted, he added.

Tracking down childhood vaccine records as an adult can be challenging — many adults may have been vaccinated before medical records were widely stored online, and their long-ago pediatricians may no longer be practicing.

People who were vaccinated in Pennsylvania after the year 2000 can search for their records in the online Pennsylvania Immunization Electronic Registry System (PIERS).

People born before 1957 are considered immune because most children contracted the virus before the vaccine was introduced.

» READ MORE: Your questions about Pennsylvania’s measles outbreak, answered

Titer blood tests can check for antibodies that indicate immunity against measles, either from the vaccine or a past infection. People with low antibodies — and therefore low protection — can get a booster.

Perhaps the fastest way to ensure you’re protected as an adult, Franklin said, is to get the MMR vaccine. The vaccine is safe to get even if you have already received it, she said.

Inquirer Chester County

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Inquirer staff writers Aubrey Whelan, Brooke Schultz, and Maddie Hanna contributed reporting.