SARS-CoV-2 viral shedding in vaccinated and unvaccinated persons: A case series.

The preclinical time course of SARS-CoV-2 shedding is not well-described. Understanding this time course will help to inform risk of SARS-CoV-2 transmission. During an outbreak in a congregate setting, we collected paired mid-turbinate nasal swabs for antigen testing and reverse-transcription polymerase chain reaction (RT-PCR) every other day from all consenting infected and exposed persons. Among 12 persons tested prospectively before and during SARS-CoV-2 infection, ten of 12 participants (83%) had completed a primary COVID-19 vaccination series prior to the outbreak. We recovered SARS-CoV-2 in viral culture from 9/12 (75%) of participants. All three persons from whom we did not recover SARS-CoV-2 in viral culture had completed their primary vaccination series. We recovered SARS-CoV-2 from viral culture in 6/9 vaccinated persons and before symptom onset in 3/6 symptomatic persons. These findings underscore the need for both non-pharmaceutical interventions and vaccination to mitigate transmission.

Transmission potential of vaccinated and unvaccinated persons infected with the SARS-CoV-2 Delta variant in a federal prison, July-August 2021.

BACKGROUND: The extent to which vaccinated persons who become infected with SARS-CoV-2 contribute to transmission is unclear. During a SARS-CoV-2 Delta variant outbreak among incarcerated persons with high vaccination rates in a federal prison, we assessed markers of viral shedding in vaccinated and unvaccinated persons. METHODS: Consenting incarcerated persons with confirmed SARS-CoV-2 infection provided mid-turbinate nasal specimens daily for 10 consecutive days and reported symptom data via questionnaire. Real-time reverse transcription-polymerase chain reaction (RT-PCR), viral whole genome sequencing, and viral culture was performed on these nasal specimens. Duration of RT-PCR positivity and viral culture positivity was assessed using survival analysis. RESULTS: A total of 957 specimens were provided by 93 participants, of whom 78 (84 %) were vaccinated and 17 (16 %) were unvaccinated. No significant differences were detected in duration of RT-PCR positivity among vaccinated participants (median: 13 days) versus those unvaccinated (median: 13 days; p = 0.50), or in duration of culture positivity (medians: 5 days and 5 days; p = 0.29). Among vaccinated participants, overall duration of culture positivity was shorter among Moderna vaccine recipients versus Pfizer (p = 0.048) or Janssen (p = 0.003) vaccine recipients. In post-hoc analyses, Moderna vaccine recipients demonstrated significantly shorter duration of culture positivity compared to unvaccinated participants (p = 0.02). When restricted to participants without reported prior infection, the difference between Moderna vaccine recipients and unvaccinated participants was more pronounced (medians: 3 days and 6 days, p = 0.002). CONCLUSIONS: Infectious periods for vaccinated and unvaccinated persons who become infected with SARS-CoV-2 are similar and can be highly variable, though some vaccinated persons are likely infectious for shorter durations. These findings are critically important, especially in congregate settings where viral transmission can lead to large outbreaks. In such settings, clinicians and public health practitioners should consider vaccinated, infected persons to be no less infectious than unvaccinated, infected persons.

Outbreak of SARS-CoV-2 B.1.617.2 (Delta) Variant Infections Among Incarcerated Persons in a Federal Prison - Texas, July-August 2021.

Incarcerated populations have experienced disproportionately higher rates of COVID-19-related illness and death compared with the general U.S. population, due in part to congregate living environments that can facilitate rapid transmission of SARS-CoV-2, the virus that causes COVID-19, and the high prevalence of underlying medical conditions associated with severe COVID-19 (1,2). The SARS-CoV-2 B.1.617.2 (Delta) variant has caused outbreaks among vaccinated and unvaccinated persons in congregate settings and large public gatherings (3,4). During July 2021, a COVID-19 outbreak involving the Delta variant was identified in a federal prison in Texas, infecting 172 of 233 (74%) incarcerated persons in two housing units. The Federal Bureau of Prisons (BOP) partnered with CDC to investigate. CDC analyzed data on infection status, symptom onset date, hospitalizations, and deaths among incarcerated persons. The attack rate was higher among unvaccinated versus fully vaccinated persons (39 of 42, 93% versus 129 of 185, 70%; p = 0.002).† Four persons were hospitalized, three of whom were unvaccinated, and one person died, who was unvaccinated. Among a subset of 70 persons consenting to an embedded serial swabbing protocol, the median interval between symptom onset and last positive reverse transcription-polymerase chain reaction (RT-PCR) test result in fully vaccinated versus unvaccinated persons was similar (9 versus 11 days, p = 0.37). One or more specimens were culture-positive from five of 12 (42%) unvaccinated and 14 of 37 (38%) fully vaccinated persons for whom viral culture was attempted. In settings where physical distancing is challenging, including correctional and detention facilities, vaccination and implementation of multicomponent prevention strategies (e.g., testing, medical isolation, quarantine, and masking) are critical to limiting SARS-CoV-2 transmission (5).

COVID-19 vaccination in the Federal Bureau of Prisons, December 2020-April 2021.

OBJECTIVES: To describe COVID-19 vaccine distribution operations in United States Federal Bureau of Prisons (BOP) institutions and offices from December 16, 2020-April 14, 2021, report vaccination coverage among staff and incarcerated people, and identify factors associated with vaccination acceptance among incarcerated people. METHODS: The BOP COVID-19 vaccination plan and implementation timeline are described. Descriptive statistics and vaccination coverage were calculated for the BOP incarcerated population using data from the BOP electronic medical record. Coverage among staff was calculated using data from the Centers for Disease Control and Prevention Vaccination Administration Management System. Vaccination coverage in the BOP versus the overall United States adult population was compared by state/territory. Univariate and multivariable logistic regression models were developed to identify demographic, health-related, and institution-level factors associated with vaccination acceptance among incarcerated people, using hierarchical linear modeling to account for institution-level clustering. RESULTS: By April 14, 2021, BOP had offered COVID-19 vaccination to 37,870 (100%) staff and 88,173/126,413 (69.8%) incarcerated people, with acceptance rates of 50.2% and 64.2%, respectively. At the time of analysis, vaccination coverage in BOP was comparable to coverage in the overall adult population in the states and territories where BOP institutions and offices are located. Among incarcerated people, factors associated with lower vaccination acceptance included younger age, female sex, non-Hispanic Black and Asian race/ethnicity, and having few underlying medical conditions; factors associated with higher acceptance included having a prior SARS-CoV-2 infection, being born outside the United States, and being assigned to a Federal Detention Center. CONCLUSIONS: Early COVID-19 vaccination efforts in BOP have achieved levels of coverage similar to the general population. To build on this initial success, BOP can consider strategies including re-offering vaccination to people who initially refused and tailoring communication strategies to groups with lower acceptance rates.

SARS-CoV-2 Infection Among Correctional Staff in the Federal Bureau of Prisons.

Objectives. To examine SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) epidemiology and risk factors among Federal Bureau of Prisons (BOP) staff in the United States.Methods. We calculated the SARS-CoV-2 case rate among 37 640 BOP staff from March 12 to June 17, 2020, using payroll and COVID-19-specific data. We compared occupational factors among staff with and without known SARS-CoV-2 using multiple logistic regression, controlling for demographic characteristics. We calculated relative risk among staff in stand-alone institutions versus complexes (> 1 institution).Results. SARS-CoV-2 was reported by 665 staff across 59.8% of institutions, a case rate of 1766.6 per 100 000. Working in dorm-style housing and in detention centers were strong risk factors, whereas cell-based housing was protective; these effects were erased in complexes. Occupational category was not associated with SARS-CoV-2.Conclusions. SARS-CoV-2 infection was more likely among staff working in institutions where physical distancing and limiting exposure to a consistent set of staff and inmates are challenging.Public Health Implications. Mitigation strategies-including augmented staff testing, entry and exit testing among inmates, limiting staff interactions across complexes, and increasing physical distancing by reducing occupancy in dorm-style housing-may prevent SARS-CoV-2 infections among correctional staff.

Mass SARS-CoV-2 Testing in a Dormitory-Style Correctional Facility in Arkansas.

Objectives. To assess SARS-CoV-2 transmission within a correctional facility and recommend mitigation strategies.Methods. From April 29 to May 15, 2020, we established the point prevalence of COVID-19 among incarcerated persons and staff within a correctional facility in Arkansas. Participants provided respiratory specimens for SARS-CoV-2 testing and completed questionnaires on symptoms and factors associated with transmission.Results. Of 1647 incarcerated persons and 128 staff tested, 30.5% of incarcerated persons (range by housing unit = 0.0%-58.2%) and 2.3% of staff tested positive for SARS-CoV-2. Among those who tested positive and responded to symptom questions (431 incarcerated persons, 3 staff), 81.2% and 33.3% were asymptomatic, respectively. Most incarcerated persons (58.0%) reported wearing cloth face coverings 8 hours or less per day, and 63.3% reported close contact with someone other than their bunkmate.Conclusions. If testing remained limited to symptomatic individuals, fewer cases would have been detected or detection would have been delayed, allowing transmission to continue. Rapid implementation of mass testing and strict enforcement of infection prevention and control measures may be needed to mitigate spread of SARS-CoV-2 in this setting.

COVID-19 Case and Mortality Rates in the Federal Bureau of Prisons.

INTRODUCTION: People living in correctional facilities are at high risk for contracting COVID-19. To characterize the burden of COVID-19 in the Federal Bureau of Prisons, inmate testing, case, and mortality rates are calculated and compared with those of the U.S. METHODS: Federal Bureau of Prisons data were derived from its inmate management system and a Federal Bureau of Prisons COVID-19-specific database. U.S. data were derived from the Centers for Disease Control and Prevention and the U.S. Census. Data were aggregated from February to September 2020 and accessed in September and November 2020. Testing rates were calculated for both the Federal Bureau of Prisons and the U.S. Case and infection fatality rates were calculated overall and by institution and compared with those of the U.S. An age- and sex-standardized mortality ratio was calculated. RESULTS: The Federal Bureau of Prisons tested more than half of its inmates (50.3%); its crude case and mortality rates were 11,710.1 and 77.4 per 100,000, respectively. Compared with the U.S., the case ratio was 4.7, and the standardized mortality ratio was 2.6. The infection fatality rate for both the Federal Bureau of Prisons and the U.S. was 0.7%. Among institutions that tested ≥85% of inmates, the combined infection fatality rate was 0.8% and ranged from 0.0% to 3.0%. CONCLUSIONS: The Federal Bureau of Prisons COVID-19 case rates and standard mortality ratio were approximately 5 and 2.5 times those in U.S. adults, respectively, consistent with those of prisons nationwide. High testing rates and standardized death reporting could result in a more accurate infection fatality rate in the Federal Bureau of Prisons than in the U.S. Testing and other mitigation strategies, including reducing the population, have likely prevented further transmission and mortality in the Federal Bureau of Prisons.

Mass Testing for SARS-CoV-2 in 16 Prisons and Jails - Six Jurisdictions, United States, April-May 2020.

Preventing coronavirus disease 2019 (COVID-19) in correctional and detention facilities* can be challenging because of population-dense housing, varied access to hygiene facilities and supplies, and limited space for isolation and quarantine (1). Incarcerated and detained populations have a high prevalence of chronic diseases, increasing their risk for severe COVID-19-associated illness and making early detection critical (2,3). Correctional and detention facilities are not closed systems; SARS-CoV-2, the virus that causes COVID-19, can be transmitted to and from the surrounding community through staff member and visitor movements as well as entry, transfer, and release of incarcerated and detained persons (1). To better understand SARS-CoV-2 prevalence in these settings, CDC requested data from 15 jurisdictions describing results of mass testing events among incarcerated and detained persons and cases identified through earlier symptom-based testing. Six jurisdictions reported SARS-CoV-2 prevalence of 0%-86.8% (median = 29.3%) from mass testing events in 16 adult facilities. Before mass testing, 15 of the 16 facilities had identified at least one COVID-19 case among incarcerated or detained persons using symptom-based testing, and mass testing increased the total number of known cases from 642 to 8,239. Case surveillance from symptom-based testing has likely underestimated SARS-CoV-2 prevalence in correctional and detention facilities. Broad-based testing can provide a more accurate assessment of prevalence and generate data to help control transmission (4).