Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 109
1.
J Appl Lab Med ; 9(3): 599-628, 2024 May 02.
Article En | MEDLINE | ID: mdl-38695489

Respiratory viral infections are among the most frequent infections experienced worldwide. The COVID-19 pandemic has highlighted the need for testing and currently several tests are available for the detection of a wide range of viruses. These tests vary widely in terms of the number of viral pathogens included, viral markers targeted, regulatory status, and turnaround time to results, as well as their analytical and clinical performance. Given these many variables, selection and interpretation of testing requires thoughtful consideration. The current guidance document is the authors' expert opinion based on the preponderance of available evidence to address key questions related to best practices for laboratory diagnosis of respiratory viral infections including who to test, when to test, and what tests to use. An algorithm is proposed to help laboratories decide on the most appropriate tests to use for the diagnosis of respiratory viral infections.


COVID-19 , Respiratory Tract Infections , SARS-CoV-2 , Humans , Respiratory Tract Infections/diagnosis , Respiratory Tract Infections/virology , COVID-19/diagnosis , SARS-CoV-2/isolation & purification , Algorithms , Clinical Laboratory Techniques/standards , Clinical Laboratory Techniques/methods , Virus Diseases/diagnosis , Virus Diseases/virology
2.
J Clin Virol ; 173: 105680, 2024 Aug.
Article En | MEDLINE | ID: mdl-38728796

BACKGROUND: Epstein-Barr Virus (EBV) viral loads in hematopoietic stem cell transplant (HSCT) recipients are typically monitored using quantitative molecular assays. The Cobas EBV test (Roche Molecular, Pleasanton, CA) has recently been FDA-cleared for the monitoring of EBV viral loads in plasma samples of transplant patients. In this study, we compared the viral loads obtained by a laboratory-developed test (EBV LDT) using Altona Analyte specific reagents (ASR) to those obtained on the Cobas EBV test. METHODS: The analytical performance of the assay was established using the EBV verification panel from Exact Diagnostics and the EBV ATCC strain B95-8. The clinical evaluation was performed using 343 plasma samples initially tested on the EBV LDT. RESULTS: The analytical sensitivity (<18.8 IU/mL), precision (SD < 0.17 log) and linear range (35.0 IU/mL to 1E + 08 IU/mL) of the Cobas EBV assay established by the manufacturers were confirmed. The strength of the qualitative agreement was substantial between the cobas EBV and the EBV LDT (85.6 %; κ = 0.71) and almost perfect when discordant results were resolved (96.4 %; κ = 0.93). The quantitative agreement was moderate (82.9 %; κ = 0.53) with the viral load obtained on the Cobas EBV test being lower across the linear range of the two tests (mean log difference of 1.0). While the absolute values of the viral loads were markedly different, the overall trends observed in patients with multiple consecutive results were similar between the two tests. CONCLUSIONS: The Cobas EBV test provides an accurate and valid, in vitro diagnostic (IVD) option for monitoring of EBV viral loads in transplant patients and should provide an opportunity for increased standardization and commutability of tests results across laboratories.


Epstein-Barr Virus Infections , Herpesvirus 4, Human , Sensitivity and Specificity , Tertiary Care Centers , Viral Load , Humans , Viral Load/methods , Epstein-Barr Virus Infections/diagnosis , Epstein-Barr Virus Infections/virology , Herpesvirus 4, Human/isolation & purification , Herpesvirus 4, Human/genetics , Middle Aged , Female , Adult , Male , Aged , Young Adult , Adolescent , Molecular Diagnostic Techniques/methods , Molecular Diagnostic Techniques/standards , Hematopoietic Stem Cell Transplantation , Child , Child, Preschool , DNA, Viral/blood , Reagent Kits, Diagnostic/standards
3.
J Clin Microbiol ; 62(3): e0001224, 2024 Mar 13.
Article En | MEDLINE | ID: mdl-38391223

The ASM Awards and Prize Program recognizes outstanding achievements in basic and applied research, clinical microbiology, education, leadership, and service. This editorial briefly describes how the program works and highlights several awards of interest to the clinical microbiology community.


Awards and Prizes , Humans , Leadership
5.
Eur J Clin Microbiol Infect Dis ; 43(3): 525-531, 2024 Mar.
Article En | MEDLINE | ID: mdl-38216845

BACKGROUND: Multiplex syndromic gastrointestinal panels (GIPCR) have streamlined the diagnosis of infectious diarrhea. Additionally, they have expanded the number of pathogens that can be routinely evaluated, allowing further understanding of the prevalence of enteric pathogens in various patient populations. The goal of this study was to investigate the prevalence and clinical presentation of astrovirus and sapovirus gastroenteritis in adult oncology patients as detected by the FilmArray GIPCR. METHODS: All GIPCR panel results from December 2017 to June 2021 were retrospectively reviewed to determine the prevalence of astrovirus and sapovirus in adult oncology patients. Medical records were also reviewed to obtain clinical information. Repeat GIPCR positivity and symptom duration were used to estimate prolonged viral shedding. RESULTS: A total of 18,014 panels were performed on samples collected from 9303 adults. Overall, astrovirus and sapovirus were detected in 0.35% (33/9303) and 0.45% (42/9303) GIPCRs respectively. At least one viral target was detected in 424 (4.4%) patients. Astrovirus accounted for 7.8% (33/424) and sapovirus 9.9% (42/424) of patients. Diarrhea was the most common symptom documented. A subset of transplant patients had protracted viral detection with a median of ~27 days (range 23-43 days) for astrovirus and 97 days (range 11-495) for sapovirus. No clusters or outbreaks were identified during the study period. CONCLUSION: In oncology patients with viral gastroenteritis, astrovirus and sapovirus were the causative agents in 18% of the cases. Both viruses were associated with mild disease. Prolonged diarrhea and viral shedding were observed in a few transplant patients.


Gastroenteritis , Neoplasms , Norovirus , Sapovirus , Adult , Humans , Infant , Sapovirus/genetics , Prevalence , Retrospective Studies , Norovirus/genetics , Gastroenteritis/diagnosis , Diarrhea/epidemiology , Neoplasms/complications , Feces , Polymerase Chain Reaction
6.
Transplant Cell Ther ; 30(1): 116.e1-116.e12, 2024 Jan.
Article En | MEDLINE | ID: mdl-37806446

Hematopoietic cell transplantation (HCT) and chimeric antigen receptor T cell therapy (CAR-T) recipients who develop Coronavirus disease 2019 (COVID-19) can have decreased overall survival (OS), likely due to disease-inherent and therapy-related immunodeficiency. The availability of COVID-19-directed therapies and vaccines have improved COVID-19-related outcomes, but immunocompromised individuals remain vulnerable. Specifically, the effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant infections, including Omicron and its sublineages, particularly in HCT recipients, remain to be defined. The aim of this study was to compare the impact of SARS-CoV-2 Omicron infections in HCT/CAR-T recipients with outcomes previously reported for ancestral SARS-CoV-2 infections early in the pandemic (March to June 2020). This was a retrospective analysis of adult HCT/CAR-T recipients diagnosed with COVID-19 at Memorial Sloan Kettering Cancer Center between July 2021 and July 2022. We identified 353 patients (172 autologous HCT recipients [49%], 152 allogeneic HCT recipients [43%], and 29 CAR-T recipients [8%]), with a median time from HCT/CAR-T to SARS-CoV-2 infection of 1010 days (interquartile range, 300 to 2046 days). Forty-one patients (12%) were diagnosed with COVID-19 during the delta wave, and 312 patients (88%) were diagnosed during the Omicron wave. Risk factors associated with increased odds of COVID-19-related hospitalization were the presence of 2 or more comorbidities (odds ratio [OR], 4.9; 95% confidence interval [CI], 2.4 to 10.7; P < .001), CAR-T therapy compared to allogeneic HCT (OR, 7.7; 95% CI, 3.0 to 20.0; P < .001), hypogammaglobulinemia (OR, 2.71; 95% CI, 1.06 to 6.40; P = .027), and age at COVID-19 diagnosis (OR, 1.03; 95% CI, 1.0 to 1.05; P = .04). In contrast, infection during the Omicron variant BA5/BA4-dominant period compared to variant BA1 (OR, .21; 95% CI, .03 to .73; P = .037) and more than 3 years from HCT/CAR-T therapy to COVID-19 diagnosis compared to early infection at <100 days (OR, .31; 95% CI, .12 to .79; P = .011) were associated with a decreased odds for hospitalization. The OS at 12 months from COVID-19 diagnosis was 89% (95% CI, 84% to 94%), with 6 of 26 deaths attributable to COVID-19. Patients with the ancestral strain of SAR-CoV-2 had a lower OS at 12 months, with 73% (95% CI, 62% to 84%) versus 89% (95% CI, 84% to 94%; P < .001) in the Omicron cohort. Specific COVID-19 treatment was administered in 62% of patients, and 84% were vaccinated with mRNA COVID-19 vaccines. Vaccinated patients had significantly better OS than unvaccinated patients (90% [95% CI, 86% to 95%] versus 82% [95% CI, 72% to 94%] at 12 months; P = .003). No significant difference in OS was observed in patients infected with the Omicron and those infected with the Delta variant (P = .4) or treated with specific COVID-19 treatments compared with those not treated (P = .2). We observed higher OS in HCT and CAR-T recipients infected with the Omicron variants compared to those infected with the ancestral strain of SARS-CoV2. The use of COVID-19 antivirals, mAbs, and vaccines might have contributed to the improved outcomes.


COVID-19 , Hematopoietic Stem Cell Transplantation , Receptors, Chimeric Antigen , Adult , Humans , SARS-CoV-2/genetics , COVID-19/therapy , COVID-19 Vaccines/therapeutic use , COVID-19 Drug Treatment , COVID-19 Testing , RNA, Viral , Receptors, Chimeric Antigen/genetics , Retrospective Studies , Hematopoietic Stem Cell Transplantation/adverse effects
7.
Cancer Immunol Res ; 12(3): 308-321, 2024 03 04.
Article En | MEDLINE | ID: mdl-38108398

Colitis induced by treatment with immune-checkpoint inhibitors (ICI), termed irColitis, is a substantial cause of morbidity complicating cancer treatment. We hypothesized that abnormal fecal microbiome features would be present at the time of irColitis onset and that restoring the microbiome with fecal transplant from a healthy donor would mitigate disease severity. Herein, we present fecal microbiota profiles from 18 patients with irColitis from a single center, 5 of whom were treated with healthy-donor fecal microbial transplantation (FMT). Although fecal samples collected at onset of irColitis had comparable α-diversity to that of comparator groups with gastrointestinal symptoms, irColitis was characterized by fecal microbial dysbiosis. Abundances of Proteobacteria were associated with irColitis in multivariable analyses. Five patients with irColitis refractory to steroids and biologic anti-inflammatory agents received healthy-donor FMT, with initial clinical improvement in irColitis symptoms observed in four of five patients. Two subsequently exhibited recurrence of irColitis symptoms following courses of antibiotics. Both received a second "salvage" FMT that was, again, followed by clinical improvement of irColitis. In summary, we observed distinct microbial community changes that were present at the time of irColitis onset. FMT was followed by clinical improvements in several cases of steroid- and biologic-agent-refractory irColitis. Strategies to restore or prevent microbiome dysbiosis in the context of immunotherapy toxicities should be further explored in prospective clinical trials.


Biological Products , Colitis , Gastrointestinal Microbiome , Humans , Fecal Microbiota Transplantation/adverse effects , Prospective Studies , Dysbiosis/therapy , Dysbiosis/etiology , Treatment Outcome , Colitis/therapy , Colitis/complications
8.
J Mol Diagn ; 25(12): 857-875, 2023 12.
Article En | MEDLINE | ID: mdl-37757952

The use of clinical molecular diagnostic methods for detecting microbial pathogens continues to expand and, in some cases, supplant conventional identification methods in various scenarios. Analytical and clinical benefits of multiplex molecular panels for the detection of respiratory pathogens have been demonstrated in various studies. The use of these panels in managing different patient populations has been incorporated into clinical guidance documents. The Association for Molecular Pathology's Infectious Diseases Multiplex Working Group conducted a review of the current benefits and challenges to using multiplex PCR for the detection of pathogens from gastrointestinal tract, central nervous system, lower respiratory tract, and joint specimens. The Working Group also discusses future directions and novel approaches to detection of pathogens in alternate specimen types, and outlines challenges associated with implementation of these multiplex PCR panels.


Communicable Diseases , Pathology, Molecular , Humans , United States , Molecular Diagnostic Techniques/methods , Multiplex Polymerase Chain Reaction/methods , Communicable Diseases/diagnosis
10.
Haematologica ; 108(11): 3058-3067, 2023 11 01.
Article En | MEDLINE | ID: mdl-37345467

AZD7442 (tixagevimab-cilgavimab) is a combination of two human monoclonal antibodies for pre-exposure prophylaxis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among high-risk patients who do not mount a reliable vaccine response. Foremost among these are hematologic malignancy patients with limited clinical trial or realworld experience to assess the effectiveness of this combination treatment since the emergence of Omicron and its subvariants. We performed a retrospective study of 892 high-risk hematologic malignancy patients who received AZD7442 at Memorial Sloan Kettering Cancer Center in New York City from January 1, 2022 to July 31, 2022. We evaluated demographic, clinical, and laboratory characteristics and performed regression analyses to evaluate risk factors for breakthrough infection. We also evaluated the impact of updated AZD7442 dosing regimens on the risk of breakthrough infection. Among 892 patients, 98 (10.9%) had a breakthrough infection during the study period. A majority received early outpatient treatment (82%) and eventually eight (8.2%) required hospitalization for management of Coronavirus Disease 2019 (COVID-19), with a single instance of severe COVID-19 and death. Patients who received a repeat dose or a higher firsttime dose of AZD7442 had a lower incidence of breakthrough infection. Univariate analyses did not reveal any significant predictors of breakthrough infection. While AZD7442 is effective at reducing SARS-CoV-2 breakthrough infection in patients with hematologic malignancies, no risk factors reliably predicted risk of infection. Patients who received updated dosing regimens as per Food and Drug Administration guidelines had better protection against breakthrough infection.


COVID-19 , Hematologic Neoplasms , Pre-Exposure Prophylaxis , Humans , COVID-19/prevention & control , SARS-CoV-2 , Breakthrough Infections , Retrospective Studies , Antibodies, Monoclonal , Hematologic Neoplasms/complications , Hematologic Neoplasms/drug therapy
11.
Mycopathologia ; 188(6): 863-871, 2023 Dec.
Article En | MEDLINE | ID: mdl-37365379

We performed a retrospective survey of non-Candida albicans candidemia in patients with cancer, including those with solid tumors and those with hematological malignancies as well as transplants patients both, solid-organ transplant recipients and hematopoietic stem cell transplant recipients. The study was performed at two healthcare centers in New York City and covered the years 2018-2022. A total of 292 patients (318 isolates) were included in the study. In order of frequency, C. glabrata (38%) was the most common species recovered, followed by C. parapsilosis (19.2%), C. tropicalis (12.6%), C. krusei (10.7%), C. lusitaniae (5.7%), and C. guilliermondii (4.4%). Micafungin was the most common antifungal treatment and 18.5% of patients were on antifungal prophylaxis. The 30-day crude mortality was 40%. 4.5% of patients had more than one non-albicans species detected. In conclusion, this study represents one of the largest surveys of non-albicans species in cancer and transplant patients and provides data on the current epidemiology of these Candida species in this patient population.


Candidemia , Neoplasms , Humans , Antifungal Agents/therapeutic use , Transplant Recipients , Retrospective Studies , Microbial Sensitivity Tests , Candida , Candidemia/drug therapy , Candidemia/epidemiology , Candidemia/microbiology , Candida glabrata , Candida parapsilosis , Candida tropicalis , Neoplasms/complications , Neoplasms/drug therapy
13.
J Clin Virol ; 163: 105442, 2023 06.
Article En | MEDLINE | ID: mdl-37075690

BACKGROUND: In March 2020, nonpharmaceutical interventions (NPIs) including face coverings and social distancing were adopted to curb the spread of SARS-CoV-2. Over the course of the pandemic, adherence to these NPIs has varied and eventually became optional in most non healthcare settings. We investigated the impact of relaxation of NPI on the incidence of respiratory viruses other than SARS-CoV-2 at a tertiary cancer care hospital. METHODS: This was a retrospective cohort study of respiratory viral panel results performed at between 08/01/2014-07/31/2022. Only one viral target result per patient per year was included. Poisson regression models were used to compare 2019-2020, 2020-2021, and 2021-2022 incidence of respiratory viruses to those of 2014-2019. Interrupted time series analysis was performed using autoregressive integrated moving average models in order to compare expected and observed positivity rates. RESULTS: A large reduction in the odds of testing positive for a respiratory virus was observed for most respiratory viruses when comparing results from 2019 to 2020 group to the corresponding period in 2014-2019. Subsequent seasons showed ongoing reductions in the odds of testing positive while slowly increasing over time back toward pre-pandemic levels. A time interrupted series analysis showed that the monthly positivity rate for all respiratory pathogens were reduced after 03/01/2020, when compared to the expected values forecast, except for adenovirus. CONCLUSIONS: This study provides valuable data that could be used to guide public health practices and support the efficacy of NPIs in curtailing the spread of novel and endemic respiratory viruses.


COVID-19 , Neoplasms , Humans , COVID-19/epidemiology , COVID-19/prevention & control , Incidence , Retrospective Studies , SARS-CoV-2 , Neoplasms/epidemiology , Neoplasms/prevention & control
15.
Infect Control Hosp Epidemiol ; 44(5): 821-823, 2023 05.
Article En | MEDLINE | ID: mdl-35506167

We used a self-reporting system to compare symptom frequency of hospital personnel with coronavirus disease 2019 before and after the emergence of the Omicron variant. Omicron was more likely to result in asymptomatic carriage (7% vs 12%; P = .009), and fewer symptoms were observed in those with booster vaccination.


COVID-19 , Humans , SARS-CoV-2 , Personnel, Hospital , Delivery of Health Care , COVID-19 Testing
17.
Clin Infect Dis ; 76(8): 1476-1482, 2023 04 17.
Article En | MEDLINE | ID: mdl-36445792

BACKGROUND: Sotrovimab is an anti-spike neutralization monoclonal antibody developed to reduce the risk of coronavirus disease 2019 (COVID-19) progression and advancement to hospitalization in high-risk patients. Currently, there is limited research describing the association of sotrovimab treatment in patients with hematologic malignancy and the predictive factors of hospitalization. METHODS: We performed an observational study of 156 consecutive cancer patients who received sotrovimab at Memorial Sloan Kettering Cancer Center in New York City during the BA.1 Omicron surge. We evaluated the demographic, clinical, and laboratory characteristics of the patients who had subsequent COVID-19-related hospitalization(s) compared to those who did not. RESULTS: Among the 156 study patients, 17 (11%) were hospitalized, of whom 4 were readmitted for COVID-19-related complications; 3 deaths were attributed to COVID-19. Results from multivariable logistic regression show that significant factors associated with hospitalization include patients on anti-CD20 therapy (adjusted odds ratio [aOR], 5.59 [95% confidence interval {CI}, 1.73-18.12]; P = .004) and with relapse/refractory disease (aOR, 5.69 [95% CI, 1.69-19.16]; P = .005). Additionally, whole genome sequencing of severe acute respiratory syndrome coronavirus 2 detected high occurrences of mutations in the spike gene associated with treatment-related resistance longitudinal samples from 11 patients treated with sotrovimab. CONCLUSIONS: While sotrovimab is effective at reducing COVID-19 hospitalization and disease severity in patients with hematologic malignancy when administered early, patients who received anti-CD20 antibodies showed substantial morbidity. Due to the high potential for resistance mutation to sotrovimab and increased morbidity in patients on anti-CD20 therapy, combination treatment should be explored to determine whether it provides added benefits compared to monotherapy.


COVID-19 , Hematologic Neoplasms , Humans , Neoplasm Recurrence, Local , Hematologic Neoplasms/complications , Hematologic Neoplasms/drug therapy , Antibodies, Neutralizing , Hospitalization
18.
Sci Rep ; 12(1): 18968, 2022 11 08.
Article En | MEDLINE | ID: mdl-36347878

The Alpha (B.1.1.7) and Omicron (B.1.1.529, BA.1, BA.4 and BA.5) variants of concern (VOC) share several mutations in their spike gene, including mutations resulting in the deletion of two amino acids at position 69 and 70 (del 69-70) in the Spike protein. Del 69-70 causes failure to detect the S gene target on a widely used, commercial test, the TaqPath SARS-CoV-2 RT-PCR (Thermo Fisher). The S gene target failure (SGTF) signature has been used to preliminarily infer the presence of Alpha and Omicron VOC. We evaluated the accuracy of the SGTF signature in identifying these two variants through analysis of all positive SARS-CoV-2 samples tested on the TaqPath RT-PCR and sequenced by next generation sequencing between December 2020 to July 2022. 2324 samples were successfully sequenced including 914 SGTF positive samples. The sensitivity and specificity of the SGTF signature was 99.6% (95% CI 96.1-99.9%) and 98.6% (95% CI 99.2-99.8%) for the Alpha variant and 99.6% (95% CI 98.9-99.9%) and 99.8% (95% CI 99.4-99.9%) for the Omicron variant. At the peak of their corresponding wave, the positive predictive value of the SGTF was 98% for Alpha and 100% for Omicron. The accuracy of the SGTF signature was high, making this genomic signature a rapid and accurate proxy for identification of these variants in real-world laboratory settings.


COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , RNA, Viral/genetics , COVID-19/genetics , Genomics
19.
mBio ; 13(5): e0222322, 2022 10 26.
Article En | MEDLINE | ID: mdl-36125317

The continued evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) necessitates that the global scientific community monitor, assess, and respond to the evolving coronavirus disease (COVID-19) pandemic. But the current reactive approach to emerging variants is ill-suited to address the quickly evolving and ever-changing pandemic. To tackle this challenge, investments in pathogen surveillance, systematic variant characterization, and data infrastructure and sharing across public and private sectors will be critical for planning proactive responses to emerging variants. Additionally, an emphasis on incorporating real-time variant identification in point-of-care diagnostics can help inform patient treatment. Active approaches to understand and identify "immunity gaps" can inform design of future vaccines, therapeutics, and diagnostics that will be more resistant to novel variants. Approaches where the scientific community actively plans for and anticipates changes to infectious diseases will result in a more resilient system, capable of adapting to evolving pathogens quickly and effectively.


COVID-19 , Vaccines , Humans , SARS-CoV-2 , Pandemics/prevention & control , COVID-19 Testing
20.
Clin Microbiol Infect ; 28(12): 1624-1628, 2022 Dec.
Article En | MEDLINE | ID: mdl-35931373

OBJECTIVE: To describe effectiveness of mRNA vaccines by comparing 2-dose (2D) and 3-dose (3D) healthcare worker (HCW) recipients in the setting of Omicron variant dominance. Performance of 2D and 3D vaccine series against SARS-CoV-2 variants and the clinical outcomes of HCWs may inform return-to-work guidance. METHODS: In a retrospective study from December 15, 2020 to January 15, 2022, SARS-CoV-2 infections among HCWs at a large tertiary cancer centre in New York City were examined to estimate infection rates (aggregated positive tests / person-days) and 95% CIs over the Omicron period in 3D and 2D mRNA vaccinated HCWs and were compared using rate ratios. We described the clinical features of post-vaccine infections and impact of prior (pre-Omicron) COVID infection on vaccine effectiveness. RESULTS: Among the 20857 HCWs in our cohort, 20,660 completed the 2D series with an mRNA vaccine during our study period and 12461 had received a third dose by January 15, 2022. The infection rate ratio for 3D versus 2D vaccinated HCWs was 0.667 (95% CI 0.623, 0.713) for an estimated 3D vaccine effectiveness of 33.3% compared to two doses only during the Omicron dominant period from December 15, 2021 to January 15, 2022. Breakthrough Omicron infections after 3D + 14 days occurred in 1,315 HCWs. Omicron infections were mild, with 16% of 3D and 11% 2D HCWs being asymptomatic. DISCUSSION: Study demonstrates improved vaccine-derived protection against COVID-19 infection in 3D versus 2D mRNA vaccinees during the Omicron surge. The advantage of 3D vaccination was maintained irrespective of prior COVID-19 infection status.


COVID-19 , Influenza Vaccines , Influenza, Human , Humans , New York City/epidemiology , SARS-CoV-2/genetics , Influenza, Human/prevention & control , RNA, Messenger/genetics , COVID-19/epidemiology , COVID-19/prevention & control , Retrospective Studies , Health Personnel , mRNA Vaccines
...