COVID-19 Vaccination Coverage, and Rates of SARS-CoV-2 Infection and COVID-19-Associated Hospitalization Among Residents in Nursing Homes - National Healthcare Safety Network, United States, October 2023-February 2024

Nursing home residents are at increased risk for developing severe COVID-19. Nursing homes report weekly facility-level data on SARS-CoV-2 infections, COVID-19-associated hospitalizations, and COVID-19 vaccination coverage among residents to CDC's National Healthcare Safety Network. This analysis describes rates of incident SARS-CoV-2 infection, rates of incident COVID-19-associated hospitalization, and COVID-19 vaccination coverage during October 16, 2023-February 11, 2024. Weekly rates of SARS-CoV-2 infection ranged from 61.4 to 133.8 per 10,000 nursing home residents. The weekly percentage of facilities reporting one or more incident SARS-CoV-2 infections ranged from 14.9% to 26.1%. Weekly rates of COVID-19-associated hospitalization ranged from 3.8 to 7.1 per 10,000 residents, and the weekly percentage of facilities reporting one or more COVID-19-associated hospitalizations ranged from 2.6% to 4.7%. By February 11, 2024, 40.5% of nursing home residents had received a dose of the updated 2023-2024 COVID-19 vaccine that was first recommended in September 2023. Although the peak rate of SARS-CoV-2 infection among nursing home residents was lower during the 2023-24 respiratory virus season than during the three previous respiratory virus seasons, nursing home residents continued to be disproportionately affected by SARS-CoV-2 infection and related severe outcomes. Vaccination coverage remains suboptimal in this population. Ongoing surveillance for SARS-CoV-2 infections and COVID-19-associated hospitalizations in this population is necessary to develop and evaluate evidence-based interventions for protecting nursing home residents.

Comparison of factors associated with seasonal influenza and COVID-19 booster vaccination coverage among healthcare personnel working at acute care hospitals during 2021-2022 influenza season, National Healthcare Safety Network, United States

The simultaneous circulation of seasonal influenza virus and SARS-CoV-2 variants will likely pose unique challenges to public health during the future influenza seasons. Persons who are undergoing treatment in healthcare facilities may be particularly at risk. It is important for healthcare personnel to protect themselves and patients by receiving vaccines. The purpose of this study is to assess coverage of the seasonal influenza vaccine and COVID-19 monovalent booster among healthcare personnel working at acute care hospitals in the United States during the 2021-22 influenza season and to examine the demographic and facility characteristics associated with coverage. A total of 3260 acute care hospitals with over 7 million healthcare personnel reported vaccination data to National Healthcare Safety Network (NHSN) during the 2021-22 influenza season. Two separate negative binomial mixed models were developed to explore the factors associated with seasonal influenza coverage and COVID-19 monovalent booster coverage. At the end of the 2021-2022 influenza season, the overall pooled mean seasonal influenza coverage was 80.3%, and the pooled mean COVID-19 booster coverage was 39.5%. Several demographic and facility-level factors, such as employee type, facility ownership, and geographic region, were significantly associated with vaccination against influenza and COVID-19 among healthcare personnel working in acute care hospitals. Our findings highlight the need to increase the uptake of vaccination among healthcare personnel, particularly non-employees, those working in for-profit and non-medical school-affiliated facilities, and those residing in the South.

Impact of the COVID-19 Pandemic on Inpatient Antibiotic Use in the United States, January 2019 Through July 2022

Antimicrobial use data reported to the National Healthcare Safety Network's Antimicrobial Use and Resistance Module between January 2019 and July 2022 were analyzed to assess the impact of the COVID-19 pandemic on inpatient antimicrobial use.

Coverage with Influenza, Respiratory Syncytial Virus, and Updated COVID-19 Vaccines Among Nursing Home Residents - National Healthcare Safety Network, United States, December 2023

Nursing home residents are at risk for becoming infected with and experiencing severe complications from respiratory viruses, including SARS-CoV-2, influenza, and respiratory syncytial virus (RSV). Fall 2023 is the first season during which vaccines are simultaneously available to protect older adults in the United States against all three of these respiratory viruses. Nursing homes are required to report COVID-19 vaccination coverage and can voluntarily report influenza and RSV vaccination coverage among residents to CDC's National Healthcare Safety Network. The purpose of this study was to assess COVID-19, influenza, and RSV vaccination coverage among nursing home residents during the current 2023-24 respiratory virus season. As of December 10, 2023, 33.1% of nursing home residents were up to date with vaccination against COVID-19. Among residents at 20.2% and 19.4% of facilities that elected to report, coverage with influenza and RSV vaccines was 72.0% and 9.8%, respectively. Vaccination varied by U.S. Department of Health and Human Services region, social vulnerability index level, and facility size. There is an urgent need to protect nursing home residents against severe outcomes of respiratory illnesses by continuing efforts to increase vaccination against COVID-19 and influenza and discussing vaccination against RSV with eligible residents during the ongoing 2023-24 respiratory virus season.

Influenza and Up-to-Date COVID-19 Vaccination Coverage Among Health Care Personnel - National Healthcare Safety Network, United States, 2022-23 Influenza Season

The Advisory Committee on Immunization Practices recommends that health care personnel (HCP) receive an annual influenza vaccine and that everyone aged ≥6 months stay up to date with recommended COVID-19 vaccination. Health care facilities report vaccination of HCP against influenza and COVID-19 to CDC's National Healthcare Safety Network (NHSN). During January-June 2023, NHSN defined up-to-date COVID-19 vaccination as receipt of a bivalent COVID-19 mRNA vaccine dose or completion of a primary series within the preceding 2 months. This analysis describes influenza and up-to-date COVID-19 vaccination coverage among HCP working in acute care hospitals and nursing homes during the 2022-23 influenza season (October 1, 2022-March 31, 2023). Influenza vaccination coverage was 81.0% among HCP at acute care hospitals and 47.1% among those working at nursing homes. Up-to-date COVID-19 vaccination coverage was 17.2% among HCP working at acute care hospitals and 22.8% among those working at nursing homes. There is a need to promote evidence-based strategies to improve vaccination coverage among HCP. Tailored strategies might also be useful to reach all HCP with recommended vaccines and protect them and their patients from vaccine-preventable respiratory diseases.

Declines in Influenza Vaccination Coverage Among Health Care Personnel in Acute Care Hospitals During the COVID-19 Pandemic - United States, 2017-2023

Health care personnel (HCP) are recommended to receive annual vaccination against influenza to reduce influenza-related morbidity and mortality. Every year, acute care hospitals report receipt of influenza vaccination among HCP to CDC's National Healthcare Safety Network (NHSN). This analysis used NHSN data to describe changes in influenza vaccination coverage among HCP in acute care hospitals before and during the COVID-19 pandemic. Influenza vaccination among HCP increased during the prepandemic period from 88.6% during 2017-18 to 90.7% during 2019-20. During the COVID-19 pandemic, the percentage of HCP vaccinated against influenza decreased to 85.9% in 2020-21 and 81.1% in 2022-23. Additional efforts are needed to implement evidence-based strategies to increase vaccination coverage among HCP and to identify factors associated with recent declines in influenza vaccination coverage.

Coronavirus disease 2019 (COVID-19) vaccination rates and staffing shortages among healthcare personnel in nursing homes before, during, and after implementation of mandates for COVID-19 vaccination among 15 US jurisdictions, National Healthcare Safety Network, June 2021-January 2022

OBJECTIVE

To examine temporal changes in coverage with a complete primary series of coronavirus disease 2019 (COVID-19) vaccination and staffing shortages among healthcare personnel (HCP) working in nursing homes in the United States before, during, and after the implementation of jurisdiction-based COVID-19 vaccination mandates for HCP.

SAMPLE AND SETTING

HCP in nursing homes from 15 US jurisdictions.

DESIGN

We analyzed weekly COVID-19 vaccination data reported to the Centers for Disease Control and Prevention's National Healthcare Safety Network from June 7, 2021, through January 2, 2022. We assessed 3 periods (preintervention, intervention, and postintervention) based on the announcement of vaccination mandates for HCP in 15 jurisdictions. We used interrupted time-series models to estimate the weekly percentage change in vaccination with complete primary series and the odds of reporting a staffing shortage for each period.

RESULTS

Complete primary series vaccination among HCP increased from 66.7% at baseline to 94.3% at the end of the study period and increased at the fastest rate during the intervention period for 12 of 15 jurisdictions. The odds of reporting a staffing shortage were lowest after the intervention.

CONCLUSIONS

These findings demonstrate that COVID-19 vaccination mandates may be an effective strategy for improving HCP vaccination coverage in nursing homes without exacerbating staffing shortages. These data suggest that mandates can be considered to improve COVID-19 coverage among HCP in nursing homes to protect both HCP and vulnerable nursing home residents.

Disparities in COVID-19 Vaccination Status Among Long-Term Care Facility Residents - United States, October 31, 2022-May 7, 2023

Residents of long-term care (LTC) facilities constitute a population that is vulnerable to SARS-CoV-2 infection; COVID-19 vaccination effectively reduces severe COVID-19 in these settings. To examine demographic differences in primary and up-to-date vaccination status against COVID-19 among LTC facility residents, a descriptive analysis of COVID-19 vaccination data from the National Healthcare Safety Network (NHSN) COVID-19 vaccination data from October 31, 2022, to May 7, 2023, were analyzed. Being up to date was defined as having received a bivalent COVID-19 vaccine dose or having completed a primary vaccination series <2 months earlier. Geographic disparities in vaccination coverage were identified, with substantially lower prevalences of up-to-date status among LTC facility residents in the South (Region 6) (37.7%) and Southeast (Region 4) (36.5%) than among those in the Pacific Northwest (Region 10) (53.3%) and Mountain West (Region 8) (59.6%) U.S. Department of Health and Human Services regions. Up-to-date status was lowest among Black or African American (39.9%) and multiracial (42.2%) LTC facility residents. Strategies to increase up-to-date COVID-19 vaccination among LTC facility residents could include and address these geographic and racial differences.

Effectiveness of Up-to-Date COVID-19 Vaccination in Preventing SARS-CoV-2 Infection Among Nursing Home Residents - United States, November 20, 2022-January 8, 2023

Nursing home residents have been disproportionately affected by the COVID-19 pandemic; their age, comorbidities, and exposure to a congregate setting has placed them at high risk for both infection and severe COVID-19-associated outcomes, including death (1). Receipt of a primary COVID-19 mRNA vaccination series (2) and monovalent booster doses (3) have been demonstrated to be effective in reducing COVID-19-related morbidity and mortality in this population. Beginning in October 2022, the National Healthcare Safety Network (NHSN) defined up-to-date vaccination as receipt of a bivalent COVID-19 mRNA vaccine dose or completion of a primary series within the preceding 2 months.* The effectiveness of being up to date with COVID-19 vaccination among nursing home residents in preventing SARS-CoV-2 infection is not known. This analysis used NHSN nursing home COVID-19 data reported during November 20, 2022-January 8, 2023, to describe effectiveness of up-to-date vaccination status (versus not being up to date) against laboratory-confirmed SARS-CoV-2 infection among nursing home residents. Adjusting for calendar week, county-level COVID-19 incidence, county-level social vulnerability index (SVI), and facility-level percentage of staff members who were up to date, up-to-date vaccine effectiveness (VE) against infection was 31.2% (95% CI = 29.1%-33.2%). Nursing home residents should stay up to date with recommended age-appropriate COVID-19 vaccination, which now includes an additional bivalent vaccine dose for moderately or severely immunocompromised adults aged ≥65 years to increase protection against SARS-CoV-2 infection.

Laboratory-Confirmed COVID-19 Case Incidence Rates Among Residents in Nursing Homes by Up-to-Date Vaccination Status - United States, October 10, 2022-January 8, 2023

Nursing home residents have been disproportionately affected by COVID-19; older age, comorbidities, and the congregate nature of nursing homes place residents at higher risk for infection and severe COVID-19-associated outcomes, including death (1). Studies have demonstrated that receipt of a primary COVID-19 mRNA vaccination series (2) and monovalent booster doses (3) is effective in reducing COVID-19-related morbidity and mortality in this population. Public health recommendations for staying up to date with COVID-19 vaccination have been revised throughout the pandemic response, most recently to include an updated (bivalent) booster dose, which protects against both the ancestral strain of SARS-CoV-2 and recent Omicron variants BA.4 and BA.5 (4). However, data on the effectiveness of staying up to date, including with bivalent booster doses, are lacking among nursing home residents. CDC's National Healthcare Safety Network (NHSN) analyzed surveillance data to examine weekly incidence rates of COVID-19 among nursing home residents by up-to-date vaccination status (receipt of a bivalent booster dose or completion of a primary series or receipt of a monovalent booster dose within the previous 2 months [i.e., not yet eligible to receive a bivalent booster dose]).* Up-to-date vaccination status among nursing home residents remained low throughout the study period, increasing to 48.9% by the week ending January 8, 2023. During October 10, 2022-January 8, 2023, the COVID-19 weekly incidence rates (new cases per 1,000 nursing home residents) among residents who were not up to date with COVID-19 vaccination were consistently higher than those among residents who were up to date. Moreover, the weekly incidence rate ratios (IRRs) indicated that residents who were not up to date with COVID-19 vaccines had a higher risk for acquiring SARS-CoV-2 than their up-to-date counterparts (IRR range = 1.3-1.5). It is critical that nursing home residents stay up to date with COVID-19 vaccines and receive a bivalent booster dose to maximize protection against COVID-19.

Effectiveness of a COVID-19 Additional Primary or Booster Vaccine Dose in Preventing SARS-CoV-2 Infection Among Nursing Home Residents During Widespread Circulation of the Omicron Variant - United States, February 14-March 27, 2022

Nursing home residents have experienced disproportionally high levels of COVID-19-associated morbidity and mortality and were prioritized for early COVID-19 vaccination (1). Following reported declines in vaccine-induced immunity after primary series vaccination, defined as receipt of 2 primary doses of an mRNA vaccine (BNT162b2 [Pfizer-BioNTech] or mRNA-1273 [Moderna]) or 1 primary dose of Ad26.COV2 (Johnson & Johnson [Janssen]) vaccine (2), CDC recommended that all persons aged ≥12 years receive a COVID-19 booster vaccine dose.* Moderately to severely immunocompromised persons, a group that includes many nursing home residents, are also recommended to receive an additional primary COVID-19 vaccine dose.† Data on vaccine effectiveness (VE) of an additional primary or booster dose against infection with SARS-CoV-2 (the virus that causes COVID-19) among nursing home residents are limited, especially against the highly transmissible B.1.1.529 and BA.2 (Omicron) variants. Weekly COVID-19 surveillance and vaccination coverage data among nursing home residents, reported by skilled nursing facilities (SNFs) to CDC's National Healthcare Safety Network (NHSN)§ during February 14-March 27, 2022, when the Omicron variant accounted for >99% of sequenced isolates, were analyzed to estimate relative VE against infection for any COVID-19 additional primary or booster dose compared with primary series vaccination. After adjusting for calendar week and variability across SNFs, relative VE of a COVID-19 additional primary or booster dose was 46.9% (95% CI = 44.8%-48.9%). These findings indicate that among nursing home residents, COVID-19 additional primary or booster doses provide greater protection against Omicron variant infection than does primary series vaccination alone. All immunocompromised nursing home residents should receive an additional primary dose, and all nursing home residents should receive a booster dose, when eligible, to protect against COVID-19. Efforts to keep nursing home residents up to date with vaccination should be implemented in conjunction with other COVID-19 prevention strategies, including testing and vaccination of nursing home staff members and visitors.

Surveillance of COVID-19 Vaccination in Nursing Homes, United States, December 2020-July 2021

Monitoring COVID-19 vaccination coverage among nursing home residents and staff is important to ensure high coverage rates and guide patient-safety policies. With the termination of the federal Pharmacy Partnership for Long-Term Care Program, another source of facility-based vaccination data is needed. We compared numbers of COVID-19 vaccinations administered to nursing home residents and staff reported by pharmacies participating in the temporary federal Pharmacy Partnership for Long-Term Care Program with the numbers of COVID-19 vaccinations reported by nursing homes participating in new COVID-19 vaccination modules of the Centers for Disease Control and Prevention's National Healthcare Safety Network (NHSN). Pearson correlation coefficients comparing the number vaccinated between the 2 approaches were 0.89, 0.96, and 0.97 for residents and 0.74, 0.90, and 0.90 for staff, in the weeks ending January 3, 10, and 17, 2021, respectively. Based on subsequent NHSN reporting, vaccination coverage with ≥1 vaccine dose reached 73.7% for residents and 47.6% for staff the week ending January 31 and increased incrementally through July 2021. Continued monitoring of COVID-19 vaccination coverage is important as new nursing home residents are admitted, new staff are hired, and additional doses of vaccine are recommended.

Carbapenemase production among less-common Enterobacterales genera: 10 US sites, 2018

Background

Historically, United States’ carbapenem-resistant Enterobacterales (CRE) surveillance and mechanism testing focused on three genera: Escherichia, Klebsiella, and Enterobacter (EsKE); however, other genera can harbour mobile carbapenemases associated with CRE spread.

Objectives

From January through May 2018, we conducted a 10 state evaluation to assess the contribution of less common genera (LCG) to carbapenemase-producing (CP) CRE.

Methods

State public health laboratories (SPHLs) requested participating clinical laboratories submit all Enterobacterales from all specimen sources during the surveillance period that were resistant to any carbapenem (Morganellaceae required resistance to doripenem, ertapenem, or meropenem) or were CP based on phenotypic or genotypic testing at the clinical laboratory. SPHLs performed species identification, phenotypic carbapenemase production testing, and molecular testing for carbapenemases to identify CP-CRE. Isolates were categorized as CP if they demonstrated phenotypic carbapenemase production and ≥1 carbapenemase gene (bla_KPC, bla_NDM, bla_VIM, bla_IMP, or bla_OXA-48-like) was detected.

Results

SPHLs tested 868 CRE isolates, 127 (14.6%) were from eight LCG. Overall, 195 (26.3%) EsKE isolates were CP-CRE, compared with 24 (18.9%) LCG isolates. LCG accounted for 24 (11.0%) of 219 CP-CRE identified. Citrobacter spp. was the most common CP-LCG; the proportion of Citrobacter that were CP (11/42, 26.2%) was similar to the proportion of EsKE that were CP (195/741, 26.3%). Five of 24 (20.8%) CP-LCG had a carbapenemase gene other than bla_KPC.

Conclusions

Participating sites would have missed approximately 1 in 10 CP-CRE if isolate submission had been limited to EsKE genera. Expanding mechanism testing to additional genera could improve detection and prevention efforts.

Effectiveness of Pfizer-BioNTech and Moderna Vaccines in Preventing SARS-CoV-2 Infection Among Nursing Home Residents Before and During Widespread Circulation of the SARS-CoV-2 B.1.617.2 (Delta) Variant - National Healthcare Safety Network, March 1-August 1, 2021

Nursing home and long-term care facility residents live in congregate settings and are often elderly and frail, putting them at high risk for infection with SARS-CoV-2, the virus that causes COVID-19, and severe COVID-19-associated outcomes; therefore, this population was prioritized for early vaccination in the United States (1). Following rapid distribution and administration of the mRNA COVID-19 vaccines (Pfizer-BioNTech and Moderna) under an Emergency Use Authorization by the Food and Drug Administration (2), observational studies among nursing home residents demonstrated vaccine effectiveness (VE) ranging from 53% to 92% against SARS-CoV-2 infection (3-6). However, concerns about the potential for waning vaccine-induced immunity and the recent emergence of the highly transmissible SARS-CoV-2 B.1.617.2 (Delta) variant† highlight the need to continue to monitor VE (7). Weekly data reported by the Centers for Medicaid & Medicare (CMS)-certified skilled nursing facilities or nursing homes to CDC's National Healthcare Safety Network (NHSN)§ were analyzed to evaluate effectiveness of full vaccination (2 doses received ≥14 days earlier) with any of the two currently authorized mRNA COVID-19 vaccines during the period soon after vaccine introduction and before the Delta variant was circulating (pre-Delta [March 1-May 9, 2021]), and when the Delta variant predominated¶ (Delta [June 21-August 1, 2021]). Using 17,407 weekly reports from 3,862 facilities from the pre-Delta period, adjusted effectiveness against infection for any mRNA vaccine was 74.7% (95% confidence interval [CI] = 70.0%-78.8%). Analysis using 33,160 weekly reports from 11,581 facilities during an intermediate period (May 10-June 20) found that the adjusted effectiveness was 67.5% (95% CI = 60.1%-73.5%). Analysis using 85,593 weekly reports from 14,917 facilities during the Delta period found that the adjusted effectiveness was 53.1% (95% CI = 49.1%-56.7%). Effectiveness estimates were similar for Pfizer-BioNTech and Moderna vaccines. These findings indicate that mRNA vaccines provide protection against SARS-CoV-2 infection among nursing home residents; however, VE was lower after the Delta variant became the predominant circulating strain in the United States. This analysis assessed VE against any infection, without being able to distinguish between asymptomatic and symptomatic presentations. Additional evaluations are needed to understand protection against severe disease in nursing home residents over time. Because nursing home residents might remain at some risk for SARS-CoV-2 infection despite vaccination, multiple COVID-19 prevention strategies, including infection control, testing, and vaccination of nursing home staff members, residents, and visitors, are critical. An additional dose of COVID-19 vaccine might be considered for nursing home and long-term care facility residents to optimize a protective immune response.

Creation of a Geospatially Explicit, Agent-based Model of a Regional Healthcare Network with Application to Clostridioides difficile Infection

Agent-based models (ABMs) describe and simulate complex systems comprising unique agents, or individuals, while accounting for geospatial and temporal variability among dynamic processes. ABMs are increasingly used to study healthcare-associated infections (ie, infections acquired during admission to a healthcare facility), including Clostridioides difficile infection, currently the most common healthcare-associated infection in the United States. The overall burden and transmission dynamics of healthcare-associated infections, including C difficile infection, may be influenced by community sources and movement of people among healthcare facilities and communities. These complex dynamics warrant geospatially explicit ABMs that extend beyond single healthcare facilities to include entire systems (eg, hospitals, nursing homes and extended care facilities, the community). The agents in ABMs can be built on a synthetic population, a model-generated representation of the actual population with associated spatial (eg, home residence), temporal (eg, change in location over time), and nonspatial (eg, sociodemographic features) attributes. We describe our methods to create a geospatially explicit ABM of a major regional healthcare network using a synthetic population as microdata input. We illustrate agent movement in the healthcare network and the community, informed by patient-level medical records, aggregate hospital discharge data, healthcare facility licensing data, and published literature. We apply the ABM output to visualize agent movement in the healthcare network and the community served by the network. We provide an application example of the ABM to C difficile infection using a natural history submodel. We discuss the ABM's potential to detect network areas where disease risk is high; simulate and evaluate interventions to protect public health; adapt to other geographic locations and healthcare-associated infections, including emerging pathogens; and meaningfully translate results to public health practitioners, healthcare providers, and policymakers.