Enrollment at Texas’s community colleges fell by 13,000 this fall. So, what’s the reason for this dip? A new report from the Texas Higher Education Coordinating Board, dissected by Inside Higher Ed‘s Paul Fain, laid out several possibilities. They’re both unsurprising (the improving economy means more employment opportunities) and surprising (could the state’s new law requiring all incoming students to receive bacterial meningitis vaccines be deterring enrollment?).

“The cost and hassle of a required vaccination shot for bacterial meningitis might be helping to drive down enrollments at Texas community colleges, another reminder of the impact of even seemingly minor barriers to college on underserved student populations,” Fain wrote.

At Unfair Park, Eric Nicholson noted that the recession brought with it “a corresponding boom at two-year colleges as students sought to gain marketable job skills without shelling out big bucks to attend costlier four-year institutions.”

But those days appear to be over: last semester, Texas’s community college population dropped 1.8 percent from fall 2011, which tracks with national trends. (Some community college systems, including Houston Community College System and the Austin Community College District, saw larger drops, of 7 and 4.5 percent respectively.) Other factors behind the drop in student enrollment may be “improving employment options in some parts of Texas, as well as tightened Pell Grant requirements and tuition increases,” Fain wrote.

All students under 30 must obtain the $125 shot or a medical waiver at least 10 days before registering for classes. To put the cost in perspective, Fain notes that $125 could cover two credit hours and thus represents “a serious cost for many community college students in Texas, where in-district tuition and fees are roughly $65 per credit.”

The rationale behind the law, passed last legislative session, was to curb the spread of the deadly disease in crowded college dormitories. Community college students, though typically commuters, are still subject to the requirement.

Rey García, president of the Texas Association of Community Colleges, agreed with this theory in an e-mail to Fain. “It might be the shot requirement is just the last straw for a student struggling to navigate college matriculation,” he wrote. And Houston Community College spokesman Dan Arguijo seemed to agree with this sentiment, telling the Houston Chronicle in December that “[a]ll those little things discourage potential students from enrolling.”