SARS-CoV-2 Infections and Reinfections among Fully Vaccinated and Unvaccinated University Athletes – 15 States, January – November 2021

Abstract Background Limited data currently exist on SARS-CoV-2 infections among fully vaccinated persons or reinfections in college-aged populations. CDC partnered with National Collegiate Athletic Association (NCAA) institutions to analyze retrospective data and present characteristics of positive COVID-19 cases among student athletes 18 years of age and older. Methods De-identified, individual-level data contributed by 21 universities on 1378 student athletes who tested positive for SARS-CoV-2 from January through November 2021 (pre-Omicron) were examined to determine percentages of infection among unvaccinated, partially vaccinated, and fully vaccinated individuals (breakthrough infections) as well as reinfections. Comparisons by demographic characteristics and regions were also made to further characterize these infections. Results Among the 1378 student athletes positive for SARS-CoV-2, 1070 (77.6%) were infected when unvaccinated and 22.4% (N = 308) were infected after full vaccination. There was a significant difference between Black (14.7%, n = 40) and White (23.9%, n = 168) student athletes who experienced a COVID-19 infection after being fully vaccinated (p < 0.01). Proportions of infections among fully vaccinated individuals did not differ statistically by sex (p = 0.06). Conclusions This paper adds to the knowledge of COVID-19 infections among fully vaccinated individuals in college-aged populations. The level of infections among fully vaccinated student athletes indicates the need for maintaining precautions to prevent infection. Further study of COVID-19 vaccination, infection, and reinfection among the well-resourced and diverse population of student athletes might contribute further understanding of factors that play a role in health equity among young adults.

Collegiate athletics programs that engage young adults in training and competition while they 2 study and socialize with other students present many challenges to the control of infectious 3 diseases. 1 Student athletes come into close contact with others during practice and competitions, 4 which could increase their risk of infection. In addition to the exposure risk from sports, they 5 also spend time in high-density common campus areas like dining halls, classrooms, and 6 residential spaces where transmission might be likely to occur. At the same time, the structured 7 lives of student athletes and their high level of general health present unique opportunities to 8 understand the dynamics of illness transmission that can inform strategies across student vaccination. The NCAA provided routinely updated guidance for athletes, coaches, and staff 16 throughout the pandemic that closely followed CDC guidance, but also provided enhanced 17 recommendations for surveillance testing of symptomatic and asymptomatic individuals. 13 18 NCAA guidance strongly recommended vaccination for all student athletes and frequent testing 19 for student athletes who were unvaccinated. 20 Institutions of higher education were required to follow all local and state guidance as well as prevention measures and high rates of surveillance testing that athletics programs put in place 9 during the 2020-2021 academic year in order to adhere to NCAA guidelines might have 10 contributed to the much lower rates of positivity among athletes during this time.

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COVID-19 vaccines are effective at decreasing rates of infection, serious illness, and death; 12 however, like other vaccines, they are not 100% effective in preventing these outcomes. 6  individual-level retrospective data for student athletes testing positive for COVID-19 was 4 received by CDC from three conferences (Big 12, Pac-12, SEC) including 21 colleges and 5 universities (32.3% of all institutions in the 5 conferences, n=65). Two conferences (Big 12, 6 SEC) included all positive cases from participating institutions; one conference (Pac-12) 7 included all positive cases from athletes who consented to have their information recorded in the 8 conference database. In addition to individual-level demographic data for each deidentified case 9 including sex, race, and sport (see Supplemental Table 1), vaccination status was obtained from 10 individual institutions by student athlete self-report. The following racial categories were 11 included for analysis: Asian American and Native Hawaiian Pacific Islander (hereafter, ANHPI),

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Black/African American (hereafter, Black), two or more races (hereafter, Multi-racial), and 13 White. American Indian Alaska Native were included for overall analysis, but excluded for 14 pairwise comparisons due to small sample size (n=2). Ethnicity was not assessed due to a high 15 level of missing data. Requirements for proof of vaccination status (such as uploading a copy of 16 vaccination card or presenting to medical staff) varied from institution to institution. Work status 17 of student athletes was not collected for this sample.

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The dataset included COVID-19 positive cases for student athletes ranging in age from 18 to 27.

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The total number of all athletes from all participating schools, and thus the overall vaccination 20 and infection rates for all athletes, was not available due to the time range of the data set crossing  and new incoming students in the fall. It should also be noted that the timespan of the data set 3 includes positive COVID-19 cases from the months before COVID-19 vaccines were widely 4 available to the general public (January-early April 2021). 5 Institutions changed testing policies over time in accordance with local, state, federal, and 6 NCAA guidance. Not all institutions conducted surveillance testing for the entire population of 7 student athletes within their athletics program on the same frequency; many focused testing on 8 those teams that were in-season. Differences in testing policies and vaccination requirements 9 varied for the athletics programs captured in the dataset (e.g., whether programs tested 10 asymptomatic or only symptomatic individuals; frequency and coverage of surveillance testing 11 for off-season student athletes). Given these factors, the study team determined that calculations 12 of aggregate numbers of student athletes would not be advisable, and all findings presented here 13 focus on characteristics of students included in the dataset of positive COVID-19 cases. 14 Additionally, due to the differences by institution in prevention polices and testing, as well as the 15 variation in numbers of athletes for any given sport across institutions, analyses by individual 16 sport were not included in this report.  Contrast analyses were conducted to determine significant differences between groups. Results

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were considered statistically significant at a p=0.05.  Across demographic categories, few differences were found in vaccination proportions (fully 11 vaccinated vs. not fully vaccinated) in our dataset (Table 1). Among females, 61.7% (n=356) 12 were fully vaccinated, and among males 61.1% (n=489) were fully vaccinated (p=0.7133). The balance of training, competition, coursework, and social activities that student athletes 5 regularly face became even more challenging over the course of the COVID-19 pandemic. 6 Coaches, trainers, and athletic staff support student athletes' health by providing guidance, contribute to health equity can make a difference for certain social categories. In general, student 20 athletes tend to show a high degree of diversity across many demographic categories such as sex 21 and race, which is also shown in our dataset. All individuals in this study received medical care 22 through their collegiate athletics programs and had access to a high level of education, nutrition, had lower rates of vaccination uptake compared to White people in the United States, although 10 the differences between groups have decreased over time. 10,11 We would suggest that the data 11 presented from our study show that in a student athlete context, that provides equitable access to 12 basic resources, differences in proportions of vaccination and infection were fairly minimal. This 13 seems to contribute some evidence to the case for improving health equity and increasing fair, 14 equitable access to basic resources like health care, education, nutrition, and secure housing, 15 which might then lead to improved health outcomes across all social demographic categories. 16 This study allows us to better understand some factors related to infections among fully universities from the five major conferences were invited to contribute to this study, but not all 20 institutions were able to supply data at the time of invitation. Thus, findings are not 21 representative of all student athletes across these conferences or student athletes in general.

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Individual case-level data were provided by partners for the January 2021-November 2021 time period only, and thus cases shown occurred before a booster shot was recommended for the 1 general population. The time period of the data set also reflects COVID-19 infections before the 2 Omicron variant became widespread in the United States.

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As mentioned in the Methods section, data on the total aggregate number of student athletes for 4 each participating institution were not available. Additionally, we were not able to collect 5 information on vaccination status for all student athletes for similar reasons. Thus, we were 6 unable to determine total vaccination rates or to calculate attack rate across the entire student 7 athlete population; this also prevented us from studying infection rate by vaccination status. 8 However, through the analyses covered above, we were able to understand some case 9 characteristics among those student athletes testing positive for COVID-19 during this time     Note: Numbers of infections among fully vaccinated student athletes are very low in January- 5 March because most student athletes were not eligible for vaccination until April 2021. Numbers 6 of student athletes who were on campus and in active training or competition in May-July were 7 lower overall due to the traditional summer break.