Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infections and Reinfections Among Fully Vaccinated and Unvaccinated University Athletes-15 States, January-November 2021.

BACKGROUND: Limited data currently exist on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections among fully vaccinated persons or reinfections in college-aged populations. Centers for Disease Control and Prevention (CDC) partnered with National Collegiate Athletic Association (NCAA) institutions to analyze retrospective data and present characteristics of positive coronavirus disease 2019 (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 SARS-CoV-2 infection after being fully vaccinated (P < .01). Proportions of infections among fully vaccinated individuals did not differ statistically by sex (p = 0.06). CONCLUSIONS: This article adds to the knowledge of SARS-CoV-2 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.

Results from a Test-to-Release from Isolation Strategy Among Fully Vaccinated National Football League Players and Staff Members with COVID-19 - United States, December 14-19, 2021.

During December 2021, the United States experienced a surge in COVID-19 cases, coinciding with predominance of the SARS-CoV-2 B.1.1.529 (Omicron) variant (1). During this surge, the National Football League (NFL) and NFL Players Association (NFLPA) adjusted their protocols for test-to-release from COVID-19 isolation on December 16, 2021, based on analytic assessments of their 2021 test-to-release data. Fully vaccinated* persons with COVID-19 were permitted to return to work once they were asymptomatic or fever-free and experiencing improving symptoms for ≥24 hours, and after two negative or high cycle-threshold (Ct) results (Ct≥35) from either of two reverse transcription-polymerase chain reaction (RT-PCR) tests† (2). This report describes data from NFL's SARS-CoV-2 testing program (3) and time to first negative or Ct≥35 result based on serial COVID-19 patient testing during isolation. Among this occupational cohort of 173 fully vaccinated adults with confirmed COVID-19 during December 14-19, 2021, a period of Omicron variant predominance, 46% received negative test results or had a subsequent RT-PCR test result with a Ct≥35 by day 6 postdiagnosis (i.e., concluding 5 days of isolation) and 84% before day 10. The proportion of persons with positive test results decreased with time, with approximately one half receiving positive RT-PCR test results after postdiagnosis day 5. Although this test result does not necessarily mean these persons are infectious (RT-PCR tests might continue to return positive results long after an initial positive result) (4), these findings indicate that persons with COVID-19 should continue taking precautions, including correct and consistent mask use, for a full 10 days after symptom onset or initial positive test result if they are asymptomatic.

Time from Start of Quarantine to SARS-CoV-2 Positive Test Among Quarantined College and University Athletes - 17 States, June-October 2020.

To safely resume sports, college and university athletic programs and regional athletic conferences created plans to mitigate transmission of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19). Mitigation measures included physical distancing, universal masking, and maximizing outdoor activity during training; routine testing; 10-day isolation of persons with COVID-19; and 14-day quarantine of athletes identified as close contacts* of persons with confirmed COVID-19. Regional athletic conferences created testing and quarantine policies based on National Collegiate Athletic Association (NCAA) guidance (1); testing policies varied by conference, school, and sport. To improve compliance with quarantine and reduce the personal and economic burden of quarantine adherence, the quarantine period has been reduced in several countries from 14 days to as few as 5 days with testing (2) or 10 days without testing (3). Data on quarantined athletes participating in NCAA sports were used to characterize COVID-19 exposures and assess the amount of time between quarantine start and first positive SARS-CoV-2 test result. Despite the potential risk for transmission from frequent, close contact associated with athletic activities (4), more athletes reported exposure to COVID-19 at social gatherings (40.7%) and from roommates (31.7%) than they did from exposures associated with athletic activities (12.7%). Among 1,830 quarantined athletes, 458 (25%) received positive reverse transcription-polymerase chain reaction (RT-PCR) test results during the 14-day quarantine, with a mean of 3.8 days from quarantine start (range = 0-14 days) until the positive test result. Among athletes who had not received a positive test result by quarantine day 5, the probability of having a positive test result decreased from 27% after day 5 to <5% after day 10. These findings support new guidance from CDC (5) in which different options are provided to shorten quarantine for persons such as collegiate athletes, especially if doing so will increase compliance, balancing the reduced duration of quarantine against a small but nonzero risk for postquarantine transmission. Improved adherence to mitigation measures (e.g., universal masking, physical distancing, and hand hygiene) at all times could further reduce exposures to SARS-CoV-2 and disruptions to athletic activities because of infections and quarantine (1,6).