Tracking COVID-19 Spread at a Midsized University

During spring 2021, when Alpha was the dominant COVID-19 variant, a midsized Midwestern university’s vaccination initiative was associated with a significant decrease in COVID-19 infections.

Many colleges have been disrupted by the COVID-19 pandemic, with some campuses partially or fully closing since the March 2020 outbreak. By spring 2021, COVID-19 vaccinations became widely available, leading some colleges to consider vaccine mandates for students, faculty, and staff.

A recent study, published in the Journal of the American Medical Association, examined whether the COVID-19 spread on college campuses is mitigated by vaccine coverage. The study took place at a midsized university located in the Midwest, and surveilled the variants that circulated the college from January 6-May 20, 2021. During the college’s spring 2021 semester, 86% of classes were held in-person, and residence halls were at full density. The university is located in a town of approximately 100000 people.

The university implemented a saliva-based surveillance system consisting of COVID-19 polymerase chain reaction (PCR) testing and genomic sequencing. During the study period, the university conducted 196185 COVID-19 tests among 14894 individuals. There were 1603 positive cases. Of those who tested positive, 59.3% were male, 89.0% were students, and 78.9%) were 17-22 years of age.

On April 7, 2021, the university announced all students needed to provide proof of COVID-19 vaccination to enroll in the fall 2021 semester. After this study concluded, the school extended the vaccine requirement to include all faculty and staff as well. From April 8-15 and April 29-May 6, 2021, the university hosted an on-campus vaccination clinic with the 2-dose mRNA Pfizer-BioNTech COVID-19 vaccine. By May 20, 2021, 90.8% of students (n = 10068), 92.2% of faculty (n = 814), and 72.0% of staff (n = 2081) were vaccinated.

The Alpha variant caused 218 of the 446 positive sequenced COVID-19 cases. By April 2021, Alpha was the only variant responsible for new COVID-19 infections. The 7-day average of positive cases peaked at 37 cases on February 17 but declined to 0 by May 14, 2021. With a statistically significant Pearson correlation coefficient of -0.57, positive cases were inversely associated with cumulative vaccine coverage. 2 weeks after the first dose of the Pfizer-BioNTech vaccine was administered, positive cases fell to their lowest levels of the semester thus far; the rate of testing was maintained.

The investigators concluded that mass vaccination caused a statistically significant decrease in the spread of COVID-19, even as the highly transmissible Alpha (B.1.1.7) variant was responsible for the majority of cases at the time.