While the majority of the Lehigh Valley is safe should measles spread here, there are unprotected pockets, state vaccination data shows.

The first cases of measles in the Lehigh Valley since 2019 were recently identified in two young children in Lehigh County. And while there is no sign of community spread, 2026 is already the worst year for measles in the United States since 1991. This largely comes down to an overall decrease in the number of children who are receiving one or both shots of the MMR vaccine.

Data recently made available in a searchable database by the Pennsylvania Department of Health shows the percentage of students who have received both doses of the measles, mumps and rubella vaccines in kindergarten and grades 7 and 12. Pennsylvania requires all students in public, private, parochial and nonpublic schools in grades K-12 to have received both doses of the MMR vaccine.

Across the Lehigh Valley, about 3.2% of children in those grades are not fully vaccinated. But that percentage varies, from a 4.6% undervaccinated rate among Northampton County kindergartners, to just 2.1% among high school seniors in Lehigh County.

For measles, it is understood that if 95% of people in a community are fully vaccinated, then herd immunity — the point where enough people are vaccinated that a disease cannot effectively spread from person to person — is achieved. Even those who are unvaccinated are protected.

Within the Lehigh Valley, about 97% of students are vaccinated, meaning that herd immunity is established. However, there are schools where rates are much lower, and there were at least 752 students in kindergarten, grade 7 and grade 12 across the Lehigh Valley who were not fully vaccinated against measles during the 2025-26 school year.

Northampton and Lehigh counties had roughly the same percentage of students who were unvaccinated, about 3%. There were at least 35 schools where 100% of students in kindergarten, grade 7 and 12 were fully vaccinated against measles, and an additional 102 had 95% or more students fully vaccinated.

There were 35 schools that reported less than 95% of students were vaccinated against measles and 36 schools only reported data for some grades, but not all three. There is no available data on children who are homeschooled.

Schools with larger student populations tended to have higher percentages of students fully vaccinated against measles and were, on average, twice as large as schools below the 95% threshold, but this was not universally true. The largest schools where less than 95% of students in kindergarten, grade 7 and grade 12 were vaccinated were:

• Lincoln Leadership Academy Charter School: 94.5%

• Southern Lehigh Middle School: 94.5%

• Shafer Elementary School, Nazareth Area School District: 94.6%

• Five Points Elementary, Bangor Area School District: 94.4%

• Northwestern Lehigh Middle School: 93%

• Bangor Area Middle School: 93%

• Eyer Middle School, East Penn School District: 92.7%

• Northern Lehigh Senior High School: 89.1%

• Seven Generations Charter School: 87.6%

• Lehigh Valley Charter High School for the Arts: 84.9%

Roughly half of the Lehigh Valley’s undervaccinated or unvaccinated children in kindergarten, or grades 7 and 12 attended schools below the 95% threshold, despite these schools only accounting for 17% of the student population in those grades.

Kindergarteners were the least protected against measles of any grade of students, despite being numerically the smallest cohort. There were about 311 kindergarteners behind on measles vaccinations, compared with 250 students in grade 7 and 192 in grade 12. The majority, 63% of kindergarteners vulnerable to measles, went to schools that were below the 95% threshold.