The CDC expects more measles cases as summer travel picks up, while Allegheny County’s kindergarten MMR rate of 94.1% sits just below the herd-immunity threshold. State data also show hundreds of students attending classes with exemptions or without any exempt
When the CDC warns measles cases will keep climbing as travel season approaches, the question hits close to home for Pittsburgh parents: how protected are the schools their children rely on?
As of April. the CDC said 1. 792 confirmed measles cases had been reported across the country. with the number expected to rise as summer travel ramps up. In Allegheny County, kindergarten vaccination rates are higher than the national average but have been declining. For kindergarteners, the measles vaccination rate—MMR—was 94.1%, just below the 95% threshold needed for herd immunity.
No measles cases have been reported in Allegheny County this year, though cases have occurred elsewhere in Pennsylvania. Still. hundreds of students attend school in Allegheny County without being fully vaccinated in ways that vary by their legal status—either through exemptions or without any exemption on file.
For Pittsburgh’s public schools, Pennsylvania’s system provides immunization rates by county, not a school-by-school breakdown. The most recent year available—2024-2025—shows how coverage looks across several major vaccines for Allegheny’s kindergarteners:
Measles, mumps and rubella: 94.1%
Polio rate: 94%
Diphtheria, tetanus and pertussis rate: 94.3%
Hepatitis B: 95.4%
Varicella: 92.4% (with another 1.4% having had the disease)
Those overall vaccination numbers matter most for measles because herd immunity depends on sustained high coverage. But the data also point to another pressure point: exemptions and non-compliance.
State records indicate that hundreds of students attended Allegheny’s schools while being exempt from receiving vaccines during the 2024-2025 school year. In kindergarten, 42 students were medically exempt (0.3%); 237 were religiously exempt (1.9%); and 221 were philosophically exempt (1.8%). In the 7th grade, the counts were 63 medically exempt (0.5%), 299 religiously exempt (2.5%), and 200 philosophically exempt (1.7%). In 12th grade, the numbers were 121 medically exempt (1%), 347 religiously exempt (2.8%), and 306 philosophically exempt (2.5%).
Exemptions aren’t the only gap. State records also indicate hundreds of unvaccinated students in Allegheny County who had not received any form of exemption but were still in the classroom during the 2024-2025 school year. The reporting said the statewide issue was even larger that same year: nearly 16. 000 students without exemptions attended schools while unvaccinated. while approximately 23. 000 students had legal exemptions—figures reported together as at least 40. 000 students in total attending classes while unvaccinated.
Locally, those numbers translate into:
Kindergarten: 295 students (2.4% of total grade population) attending while non-compliant with vaccines
7th grade: 605 students (5.1%)
12th grade: 519 (4.2%)
On top of that, the data show 475 students were in the process of completing their required vaccinations at the time of enrollment. Across grades, 14 students were denied admission due to vaccine status.
The CDC defines herd immunity for measles as occurring when more than 95% of a community is vaccinated against the disease. In Allegheny County’s 2024-2025 school year, kindergarteners vaccinated against measles were at 94.1%, according to state records.
The coverage also hasn’t stayed steady. Over recent years, the rate of kindergarteners vaccinated against measles in Allegheny County was reported as:
2024-2025: 94.1%
2023-2024: 94.4%
2022-2023: 94.8%
2021-2022: 95.7%
2020-2021: 96.7%
Statewide, records showed kindergarten MMR rates in 2024-2025 were also below the herd-immunity threshold, at 93.7%. Nationwide, the rate was reported as 92.5%.
The tension between “no cases so far” and “protection that’s not at target” is hard to miss. Even with Allegheny County reporting no measles cases in 2026. the national situation is moving in the wrong direction: the CDC said 1. 842 confirmed measles cases had been reported in 2026. as of a CDC report published May 8.
That same CDC report found 2,288 confirmed cases of measles in 2025. For 2026, it also cited 25 new outbreaks.
This year’s spread has extended beyond Pennsylvania into many states. including Alaska. Arizona. California. Colorado. the District of Columbia. Florida. Georgia. Idaho. Illinois. Kentucky. Louisiana. Maine. Maryland. Massachusetts. Michigan. Minnesota. Missouri. Montana. Nebraska. New Jersey. New Mexico. New York. North Carolina. North Dakota. Ohio. Oklahoma. Oregon. Rhode Island. South Carolina. South Dakota. Texas. Utah. Vermont. Virginia. Washington. Wisconsin and Wyoming.
In that 2026 total of 1. 842 confirmed cases. 21% involved people under five years old. 51% sickened those between the ages of five and 19. and 27% involved people over 20. The CDC also reported that six cases involved individuals whose ages weren’t known. Of those sickened, 92% were unvaccinated or had an unknown vaccine status, and an additional 4% had only received one MMR dose.
Pennsylvania’s story within that broader picture includes cases concentrated outside Allegheny County. The CDC reported only 15 cases throughout Pennsylvania. while the state department of health said there were 23 people who caught measles this year. Most of those cases occurred in Lebanon and Lancaster counties. Of the 23 people sickened, 22 were unvaccinated, while one patient had a vaccination status that couldn’t be verified.
Why the focus on MMR matters is grounded in how the disease spreads and what vaccines can prevent. Measles is an airborne disease that spreads when an infected person exhales. coughs or sneezes. and it can remain in the air for two hours after the infected person has left the area. Droplets can also remain infectious on surfaces.
A person with measles is contagious from four days before the development of a rash to four days after the rash erupts.
Symptoms typically show up seven to 14 days after exposure. The CDC lists high fever. cough. runny nose. red. watery eyes. Koplik spots (white spots inside the mouth). and a rash that generally appears three to five days after the first symptoms—starting as flat red spots on the face and hairline before spreading downward.
Complications can be severe and include ear infection. diarrhea. hospitalization. pneumonia. encephalitis (which can lead to convulsions. deafness or intellectual disability). and subacute sclerosing panencephalitis. described as a fatal disease of the nervous system. Death is listed as a possible outcome, along with pregnancy complications such as premature birth or a low-birth-weight baby.
Two doses of the MMR vaccine provide 97% protection against the virus, according to the CDC. Children usually receive their first dose at 12 to 15 months and a second at four to six years. The CDC also estimated that one in five people who aren’t vaccinated and get measles will need to be hospitalized.
Those born before 1957 are presumed to have acquired immunity, according to the National Foundation for Infectious Diseases.
For Pittsburgh and the broader Allegheny County region. the numbers describe a community that’s better protected than average—but not fully insulated. Kindergarteners in 2024-2025 hit 94.1% for MMR coverage, below the 95% herd-immunity threshold, and the trend has moved downward from 96.7% in 2020-2021.
At the same time. the enrollment data show multiple pathways into classrooms for students who are not vaccinated in compliance with vaccine requirements—exemptions that include medical. religious and philosophical reasons; students without exemptions on file; and students completing required vaccinations at enrollment. With no reported cases in Allegheny County this year. the district is still operating in a window where prevention is working—but it isn’t operating with the coverage level measles requires.
The CDC’s warning that more cases are expected to come with travel season gives that window an edge. If measles finds enough unprotected pockets. outbreaks don’t need to start with many infections—only the conditions for rapid spread. And for Pittsburgh-area schools. the challenge is now clear: keep coverage from drifting further downward. while bringing students closer to the protection level that measles cannot easily overcome.
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