Effectiveness of a bivalent mRNA vaccine dose against symptomatic SARS-CoV-2 infection among U.S. Healthcare personnel, September 2022-May 2023.

BACKGROUND: Bivalent mRNA vaccines were recommended since September 2022. However, coverage with a recent vaccine dose has been limited, and there are few robust estimates of bivalent VE against symptomatic SARS-CoV-2 infection (COVID-19). We estimated VE of a bivalent mRNA vaccine dose against COVID-19 among eligible U.S. healthcare personnel who had previously received monovalent mRNA vaccine doses. METHODS: We conducted a case-control study in 22 U.S. states, and enrolled healthcare personnel with COVID-19 (case-participants) or without COVID-19 (control-participants) during September 2022-May 2023. Participants were considered eligible for a bivalent mRNA dose if they had received 2-4 monovalent (ancestral-strain) mRNA vaccine doses, and were ≥67 days after the most recent vaccine dose. We estimated VE of a bivalent mRNA dose using conditional logistic regression, accounting for matching by region and four-week calendar period. We adjusted estimates for age group, sex, race and ethnicity, educational level, underlying health conditions, community COVID-19 exposure, prior SARS-CoV-2 infection, and days since the last monovalent mRNA dose. RESULTS: Among 3,647 healthcare personnel, 1,528 were included as case-participants and 2,119 as control-participants. Participants received their last monovalent mRNA dose a median of 404 days previously; 1,234 (33.8%) also received a bivalent mRNA dose a median of 93 days previously. Overall, VE of a bivalent dose was 34.1% (95% CI, 22.6%-43.9%) against COVID-19 and was similar by product, days since last monovalent dose, number of prior doses, age group, and presence of underlying health conditions. However, VE declined from 54.8% (95% CI, 40.7%-65.6%) after 7-59 days to 21.6% (95% CI 5.6%-34.9%) after ≥60 days. CONCLUSIONS: Bivalent mRNA COVID-19 vaccines initially conferred approximately 55% protection against COVID-19 among U.S. healthcare personnel. However, protection waned after two months. These findings indicate moderate initial protection against symptomatic SARS-CoV-2 infection by remaining up-to-date with COVID-19 vaccines.

Effectiveness of a Messenger RNA Vaccine Booster Dose Against Coronavirus Disease 2019 Among US Healthcare Personnel, October 2021-July 2022.

Background: Protection against symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (coronavirus disease 2019 [COVID-19]) can limit transmission and the risk of post-COVID conditions, and is particularly important among healthcare personnel. However, lower vaccine effectiveness (VE) has been reported since predominance of the Omicron SARS-CoV-2 variant. Methods: We evaluated the VE of a monovalent messenger RNA (mRNA) booster dose against COVID-19 from October 2021 to June 2022 among US healthcare personnel. After matching case-participants with COVID-19 to control-participants by 2-week period and site, we used conditional logistic regression to estimate the VE of a booster dose compared with completing only 2 mRNA doses >150 days previously, adjusted for multiple covariates. Results: Among 3279 case-participants and 3998 control-participants who had completed 2 mRNA doses, we estimated that the VE of a booster dose against COVID-19 declined from 86% (95% confidence interval, 81%-90%) during Delta predominance to 65% (58%-70%) during Omicron predominance. During Omicron predominance, VE declined from 73% (95% confidence interval, 67%-79%) 14-60 days after the booster dose, to 32% (4%-52%) ≥120 days after a booster dose. We found that VE was similar by age group, presence of underlying health conditions, and pregnancy status on the test date, as well as among immunocompromised participants. Conclusions: A booster dose conferred substantial protection against COVID-19 among healthcare personnel. However, VE was lower during Omicron predominance, and waning effectiveness was observed 4 months after booster dose receipt during this period. Our findings support recommendations to stay up to date on recommended doses of COVID-19 vaccines for all those eligible.

Emergency department personnel patient care-related COVID-19 risk.

OBJECTIVES: Emergency department (ED) health care personnel (HCP) are at risk of exposure to SARS-CoV-2. The objective of this study was to determine the attributable risk of SARS-CoV-2 infection from providing ED care, describe personal protective equipment use, and identify modifiable ED risk factors. We hypothesized that providing ED patient care increases the probability of acquiring SARS-CoV-2 infection. METHODS: We conducted a multicenter prospective cohort study of 1,673 ED physicians, advanced practice providers (APPs), nurses, and nonclinical staff at 20 U.S. centers over 20 weeks (May to December 2020; before vaccine availability) to detect a four-percentage point increased SARS-CoV-2 incidence among HCP related to direct patient care. Participants provided monthly nasal and serology specimens and weekly exposure and procedure information. We used multivariable regression and recursive partitioning to identify risk factors. RESULTS: Over 29,825 person-weeks, 75 participants (4.5%) acquired SARS-CoV-2 infection (31 were asymptomatic). Physicians/APPs (aOR 1.07; 95% CI 0.56-2.03) did not have higher risk of becoming infected compared to nonclinical staff, but nurses had a marginally increased risk (aOR 1.91; 95% CI 0.99-3.68). Over 99% of participants used CDC-recommended personal protective equipment (PPE), but PPE lapses occurred in 22.1% of person-weeks and 32.1% of SARS-CoV-2-infected patient intubations. The following factors were associated with infection: household SARS-CoV-2 exposure; hospital and community SARS-CoV-2 burden; community exposure; and mask non-use in public. SARS-CoV-2 intubation was not associated with infection (attributable risk fraction 13.8%; 95% CI -2.0-38.2%), and nor were PPE lapses. CONCLUSIONS: Among unvaccinated U.S. ED HCP during the height of the pandemic, the risk of SARS-CoV-2 infection was similar in nonclinical staff and HCP engaged in direct patient care. Many identified risk factors were related to community exposures.

Effectiveness of mRNA Covid-19 Vaccine among U.S. Health Care Personnel.

BACKGROUND: The prioritization of U.S. health care personnel for early receipt of messenger RNA (mRNA) vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (Covid-19), allowed for the evaluation of the effectiveness of these new vaccines in a real-world setting. METHODS: We conducted a test-negative case-control study involving health care personnel across 25 U.S. states. Cases were defined on the basis of a positive polymerase-chain-reaction (PCR) or antigen-based test for SARS-CoV-2 and at least one Covid-19-like symptom. Controls were defined on the basis of a negative PCR test for SARS-CoV-2, regardless of symptoms, and were matched to cases according to the week of the test date and site. Using conditional logistic regression with adjustment for age, race and ethnic group, underlying conditions, and exposures to persons with Covid-19, we estimated vaccine effectiveness for partial vaccination (assessed 14 days after receipt of the first dose through 6 days after receipt of the second dose) and complete vaccination (assessed ≥7 days after receipt of the second dose). RESULTS: The study included 1482 case participants and 3449 control participants. Vaccine effectiveness for partial vaccination was 77.6% (95% confidence interval [CI], 70.9 to 82.7) with the BNT162b2 vaccine (Pfizer-BioNTech) and 88.9% (95% CI, 78.7 to 94.2) with the mRNA-1273 vaccine (Moderna); for complete vaccination, vaccine effectiveness was 88.8% (95% CI, 84.6 to 91.8) and 96.3% (95% CI, 91.3 to 98.4), respectively. Vaccine effectiveness was similar in subgroups defined according to age (<50 years or ≥50 years), race and ethnic group, presence of underlying conditions, and level of patient contact. Estimates of vaccine effectiveness were lower during weeks 9 through 14 than during weeks 3 through 8 after receipt of the second dose, but confidence intervals overlapped widely. CONCLUSIONS: The BNT162b2 and mRNA-1273 vaccines were highly effective under real-world conditions in preventing symptomatic Covid-19 in health care personnel, including those at risk for severe Covid-19 and those in racial and ethnic groups that have been disproportionately affected by the pandemic. (Funded by the Centers for Disease Control and Prevention.).

Interim Estimates of Vaccine Effectiveness of Pfizer-BioNTech and Moderna COVID-19 Vaccines Among Health Care Personnel - 33 U.S. Sites, January-March 2021.

Throughout the COVID-19 pandemic, health care personnel (HCP) have been at high risk for exposure to SARS-CoV-2, the virus that causes COVID-19, through patient interactions and community exposure (1). The Advisory Committee on Immunization Practices recommended prioritization of HCP for COVID-19 vaccination to maintain provision of critical services and reduce spread of infection in health care settings (2). Early distribution of two mRNA COVID-19 vaccines (Pfizer-BioNTech and Moderna) to HCP allowed assessment of the effectiveness of these vaccines in a real-world setting. A test-negative case-control study is underway to evaluate mRNA COVID-19 vaccine effectiveness (VE) against symptomatic illness among HCP at 33 U.S. sites across 25 U.S. states. Interim analyses indicated that the VE of a single dose (measured 14 days after the first dose through 6 days after the second dose) was 82% (95% confidence interval [CI] = 74%-87%), adjusted for age, race/ethnicity, and underlying medical conditions. The adjusted VE of 2 doses (measured ≥7 days after the second dose) was 94% (95% CI = 87%-97%). VE of partial (1-dose) and complete (2-dose) vaccination in this population is comparable to that reported from clinical trials and recent observational studies, supporting the effectiveness of mRNA COVID-19 vaccines against symptomatic disease in adults, with strong 2-dose protection.

Portable, consumer-grade pulse oximeters are accurate for home and medical use: Implications for use in the COVID-19 pandemic and other resource-limited environments.

OBJECTIVE: To determine the correlation between 3 lightweight portable pulse oximeter devices compared to a standard wall mount pulse oximetry device. METHODS: We performed a single-center, prospective, observational study of 4 pulse oximetry devices, 3 of which are commercially available to the public. A convenience sample of 200 emergency department (ED) patients with chief complaints of cardiopulmonary origin or a peripheral capillary oxygen saturation ≤ 94 percent were enrolled. Analysis of variance was performed to compare SpO2s and test characteristics of the 3 devices compared to control. RESULTS: Although differences in measured SpO2s were observed (P < 0.001) across groups, the differences were small (mean differences ranged from 1.00% to 1.87%). The correlation between test devices and the control were high (r range 0.70-0.79). Although the test characteristics were not perfect, the devices did have good sensitivity using a cutoff value of 94% (sensitivity ranging from 90% to 92%), which improved with lower SpO2 cutoff values to 92% (sensitivity ranging from 96% to 97%). CONCLUSION: The 3 commercially available devices were accurate enough to be clinically useful when compared to a hospital bedside monitor pulse oximeter. Consumer-grade portable pulse oximeters may be useful if overwhelming numbers of patients require oxygen saturation monitoring, such as during the COVID-19 pandemic.

Telemedicine in the emergency department in the era of COVID-19: front-line experiences from 2 institutions.

During the COVID-19 pandemic, one of the major changes that has occurred in emergency medicine is the evolution of telemedicine. With relaxation of regulatory and administrative barriers, the use of this already available technology has rapidly expanded. Telemedicine provides opportunity to markedly decrease personal protective equipment (PPE) and reduce healthcare worker exposures. Moreover, with the convenience and availability of access to medical care via telemedicine, a more fundamental change in healthcare delivery in the United States is likely. The implementation of telemedicine in the emergency department (ED) in particular has great potential to prevent the iatrogenic spread of COVID-19 and protect health care workers. Challenges to widespread adoption of telemedicine include privacy concerns, limitation of physical examination, and concerns of patient experience. In this clinical review, we discuss ED telemedicine applications, logistics, and challenges in the COVID-19 era as well as recent regulatory and legal changes. In addition, examples of telemedicine use are described from 2 institutions. Examples of future applications of telemedicine within the realm of emergency medicine are also discussed.

The utility of iPhone oximetry apps: A comparison with standard pulse oximetry measurement in the emergency department.

OBJECTIVES: To determine if a correlation exists between 3 iphone pulse ox applications' measurements and the standard pulse oximetry (SpO2) and whether these applications can accurately determine hypoxia. METHODS: Three applications reportedly measuring SpO2 were downloaded onto an iPhone 5s. Two of these applications used the onboard light and camera lens "Pulse Oximeter" (Pox) and "Heart Rate and Pulse Oximeter" (Ox) and one used an external device that plugged into the iphone (iOx). Patients in the ED were enrolled with chief complaints of cardiac/pulmonary origin or a SpO2 ≤ 94%. All measurements were compared to controls. Concordance correlation coefficients, sensitivity, and specificity were calculated. RESULTS: A total of 191 patients were enrolled. The concordance correlation of iOx with control was 0.55 (CI 0.46, 0.63), POx was 0.01 (CI -0.09, 0.11), and Ox was 0.07 (CI -0.02, 0.15). 68/191 patients (35%) were found to have hypoxemia. Sensitivities for detecting hypoxia were 69%, 0%, and 7% for iOx, POx, and Ox, respectively. Specificities were 89%, 100%, and 89%. Even iOx (the most accurate) 21 (11%) were incorrectly classified nonhypoxic, and 22 (12%) were incorrectly classified hypoxic. CONCLUSIONS: While iOx has modest concordance with control, Ox and POx showed almost none. The iOx device was best in correctly identifying hypoxia patients, but almost 1/4 of patients were incorrectly classified. The three apps provided inaccurate SpO2 measurements and had limited to no ability to accurately detect hypoxia. These apps should not be relied upon to provide accurate SpO2 measurements in emergent, even austere conditions.

Core Content for Wilderness Medicine Training: Development of a Wilderness Medicine Track Within an Emergency Medicine Residency.

Wilderness medicine training has become increasingly popular among medical professionals with numerous educational opportunities nationwide. Curricula for fellowship programs and for medical student education have previously been developed and published, but a specific curriculum for wilderness medicine education during emergency medicine (EM) residency has not. The objective of this study is to create a longitudinal wilderness medicine curriculum that can be incorporated into an EM residency program. Interest-specific tracks are becoming increasingly common in EM training. We chose this model to develop our curriculum specific to wilderness medicine. Outlined in the article is a 3-year longitudinal course of study that includes a core didactic curriculum and a plan for graduated level of responsibility. The core content is specifically related to the required EM core content for residency training with additions specific to wilderness medicine for the residents who pursue the track. The wilderness medicine curriculum would give residencies a framework that can be used to foster learning for residents interested in wilderness medicine. It would enhance the coverage of wilderness and environmental core content education for all EM residents in the program. It would provide wilderness-specific education and experience for interested residents, allowing them to align their residency program requirements through a focused area of study and enhancing their curriculum vitae at graduation. Finally, given the popularity of wilderness medicine, the presence of a wilderness medicine track may improve recruitment for the residency program.

The effect of sonologist experience on the ability to determine endotracheal tube location using transtracheal ultrasound.

STUDY OBJECTIVE: Transtracheal ultrasound has been described as a method to evaluate endotracheal tube placement. Correlation between sonologist experience and the successful use of transtracheal ultrasound to identify endotracheal tube location has not been examined. Our objectives were to evaluate emergency physicians' ability to correctly identify endotracheal tube location using transtracheal ultrasound and to evaluate the role operator experience plays in successful identification of tube placement. METHODS: This was a cross-sectional, single-blinded study conducted in a cadaver laboratory. Two cadavers were used as models. One cadaver had an endotracheal tube placed in the esophagus, and the second had the tube placed in the trachea. Participants were asked to evaluate tube placement using transtracheal ultrasound and to record their interpretation. Examination clips were reviewed by the emergency ultrasound fellowship director. Descriptive statistics and χ(2) test were used for analysis. RESULTS: Twenty-nine participants were included, 8 (27.6%) of whom were considered to be "most experienced" based on previous ultrasound experience (>150 scans). Eleven of 29 correctly identified esophageal intubation and 18 of 29 correctly identified tracheal intubation, resulting in a sensitivity of 62.0% (95% confidence interval [CI], 42.3-79.3) and a specificity of 37.9% (95% CI, 20.7-57.7). Transtracheal ultrasound performed by the most experienced sonologists showed better sensitivity and specificity, 75.0% (95% CI, 34.9-96.8) and 62.5% (95% CI, 24.5-91.5), respectively. CONCLUSION: Most participants obtained adequate images, but correct interpretation of the images was poor. The most experienced sonologists correctly identified tube location more often. Additional education would be required before adopting this method.

The Rusch ViewMax vs Macintosh laryngoscopy in human cadavers: impoved vocal cord visualization?

OBJECTIVES: Adequate vocal cord visualization via laryngoscopy is a key component of successful endotracheal intubation. Several tools exist to facilitate laryngoscopy in difficult airways. We compared one such device, the Rusch "ViewMax" (Rusch, Duluth, Ga), to a standard Macintosh laryngoscope blade (Heine USA Ltd, Dover, NH) using human cadaver models. The purpose of this study was to determine if the ViewMax improved vocal cord visualization. METHODS: Emergency medicine residents and faculty (N = 26) attempted vocal cord visualization with both ViewMax and Macintosh laryngoscope blades for each of 6 cadaver airways at an airway laboratory training exercise. Percentage of glottic opening (POGO) score was estimated for each laryngoscopy attempt. Data were analyzed by nonparametric statistics. RESULTS: Of 6 cadaver airways, 4 had median POGO score estimates of 100% for both ViewMax and Macintosh laryngoscope blades. Two cadavers had median POGO estimates of less than 50% for both blades. No difference was found in POGO score estimates between the ViewMax and the Macintosh blades in any of the 6 cadavers including those with more difficult vocal cord visualization (P = .27, .35, .61, .40, .39, .31). CONCLUSION: The Rusch "ViewMax" was not shown to improve vocal cord visualization over standard Macintosh blade laryngoscopy in these cadaver models. Further study with cadaver models known to have more difficult airways may improve power to detect a small difference in vocal cord visualization, though the clinical relevance of any slight difference remains uncertain.