key: cord-0871628-1hntkpne
authors: Teran, Richard A.; Walblay, Kelly A.; Shane, Elizabeth L.; Xydis, Shannon; Gretsch, Stephanie; Gagner, Alexandra; Samala, Usha; Choi, Hyeree; Zelinski, Christy; Black, Stephanie R.
title: Postvaccination SARS‐CoV‐2 infections among skilled nursing facility residents and staff members — Chicago, Illinois, December 2020–March 2021
date: 2021-06-04
journal: Am J Transplant
DOI: 10.1111/ajt.16634
sha: acdfb569222e41a324ffe4d91425705026015d90
doc_id: 871628
cord_uid: 1hntkpne

This article describes 22 cases of breakthrough SARS‐CoV‐2 infection among over 14,000 fully vaccinated skilled nursing facility residents and staff. The majority of such infections were asymptomatic or were associated with mild symptoms, and there was no intra‐ facility spread related to these cases. This report suggests that postvaccination breakthrough infections are rare, but also confirms that vaccines do not offer 100% protection even in nonimmunosuppressed hosts, thus underscoring the need for studies of vaccine efficacy in immunosuppressed transplant recipients.

Early studies suggest that COVID-19 vaccines protect against severe illness; 1 however, postvaccination SARS-CoV-2 infections (i.e., breakthrough infections) can occur because COVID-19 vaccines do not offer 100% protection. 2 or staff member was defined as a receipt of a positive SARS-CoV-2 NAAT or antigen test result from a respiratory specimen collected ≥14 days after completing the two-dose COVID-19 vaccination series. ** Infection prevention specialists conducted case investigations to assess symptoms, clinical outcomes, and close contact information.

SARS-CoV-2 incidence during the investigation period was assessed across four groups based on vaccination status at the time a positive respiratory specimen was collected: (1) unvaccinated (never received a COVID-19 vaccine dose); (2) partially vaccinated (received one dose of a two-dose series); (3) vaccinated but not immune (received two doses of a two-dose series but <14 days had elapsed since the second dose); and (4) fully vaccinated (received two doses of a two-dose series and ≥14 days had elapsed since the second dose). In addition to routine facility follow-up, CDPH actively monitored facilities with breakthrough infections for 28 days to identify whether any new cases occurred in close contacts of the person with breakthrough infection. † † Analyses were completed using SAS (version 9.4; SAS Institute). This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy. § § During the investigation period, an estimated 7931 SNF residents and 6834 staff members received two doses of COVID-19 vaccine. A total of 627 confirmed SARS-CoV-2 infections were identified across 75 of the 78 Chicago-based SNFs, including 353 (56%) among residents and 274 (44%) among staff members during the investigation period (Table 1) . Three facilities had no confirmed SARS-CoV-2 infections after their first vaccination clinic. Approximately one half (47%) of resident cases occurred in men, 42% were in non-Hispanic Black persons, and the median age was 71 years. More than two-thirds (72%) of staff member cases were in women, 38% were in non-Hispanic Black persons, and the median age was 42 years. The positive result might have been related to an episode of pneumonia diagnosed 9 days after the second dose. COVID-19 testing was not associated with compatible symptoms, and this resident was included because the resident's case met the laboratory-based breakthrough infection definition. This resident likely did not experience a breakthrough infection because previous pneumonia onset is suggestive of SARS-CoV-2 infection before full immunization.

f Resident D5 had a positive preprocedural SARS-CoV-2 test result and was subsequently hospitalized for non-COVID-19-related reasons, including multiple falls and a bloodstream infection related to a midline catheter. Residents and staff members were excluded from the investigation if they had received 1) a positive SARS-CoV-2 test result from December 28 through the date of their facility's first vaccination clinic or 2) a known initial positive SARS-CoV-2 test result <90 days before their most recent SARS-CoV-2 test result. † † For residents, close contact was defined as being within 6 ft of a person for ≥15 minutes over a 24-hour period, regardless of personal protective equipment used. For staff members, close contact was defined as being within 6 ft of a person for ≥15 minutes over a 24-hour period when one or both persons were unmasked. § § 45 C.F.R. part 46, 21 C.F.R. part 56; 42 U.S.C. Sect. 241(d); 5 U.S.C.

Sect.552a; 44 U.S.C. Sect.3501 et seq. ¶ ¶ To calculate attack rates, residents and staff members who had never received COVID-19 vaccine (i.e., unvaccinated persons) and those who had received one COVID-19 vaccine dose of a two-dose series (i.e., partially vaccinated persons) were categorized as unvaccinated.

Residents and staff members who had received two COVID-19 vaccine doses of a two-dose series and <14 days or ≥14 days had elapsed (i.e., vaccinated but not immune and fully vaccinated persons, respectively) were categorized as vaccinated. Aggregate vaccination data were only available for residents and staff members who received two doses of COVID-19 vaccine and did not have a SARS-CoV-2 infection. In the denominator, differentiation between persons who received two doses <14 days or ≥14 days was not possible.

*** Cases identified within a 28-day monitoring window from the date of specimen collection for the breakthrough infection. For facilities with multiple breakthrough infections, 28-day monitoring windows might overlap, and new facility cases might be listed multiple times. As of April 12, 2021, nine of the 41 cases were breakthrough infections; seven of which are listed (see Table 2 ) and occurred during the investigation period.

Interim estimates of vaccine effectiveness of BNT162b2 and mRNA-1273 COVID-19 vaccines in preventing SARS-CoV-2 infection among health care personnel, first responders, and other essential and frontline workers-eight U.S. locations

COVE Study Group. Efficacy and safety of the mRNA-123 SARS-CoV-2 vaccine

C4591001 Clinical Trial Group. Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine

Rates of COVID-19 among residents and staff members in nursing homes-United States

COVID-19 nursing home data. Baltimore, MD: US Department of Health and Human Services

The Advisory Committee on Immunization Practices' interim recommendation for allocating initial supplies of COVID-19 vaccine-United States

Early COVID-19 first-dose vaccination coverage among residents and staff members of skilled nursing facilities participating in the Pharmacy Partnership for Long-Term Care Program-United States

Effectiveness of the Pfizer-BioNTech COVID-19 vaccine among residents of two skilled nursing facilities experiencing COVID-19 outbreaks-Connecticut

Intermittent viral shedding in respiratory samples of patients with SARS-CoV-2: observational analysis with infection control implications

Postvaccination SARS-CoV-2 infections among skilled nursing facility residents and staff members