Myocardium damage and electrocardiogram characteristics of patients infected with SARS-CoV-2 Omicron variant in Zhuhai

Aim To explore the myocardial damage, abnormal electrocardiogram characteristics of patients infected with SARS-CoV-2 Omicron variant in Zhuhai. Methods 84 patients with SARS-CoV-2 Omicron variant (Omicron variant group) admitted to the Fifth Affiliated Hospital of Sun Yat-sen University from January 13 to March 20, 2022 were included, and 88 patients with non SARS-CoV-2 Omicron variant (non-Omicron variant group) from January 17 to February 17, 2020 were included. A retrospective study was conducted to compare myocardial damage, abnormal electrocardiogram and clinical characteristics between the two groups. Results The mean age of patients in Omicron variant group was smaller than that in non-Omicron variant group [(36. 6±15. 6) years vs. (49. 8±14. 3) years, P<0. 01], and the proportion of patients with body temperature, systolic blood pressure and fever at admission was lower than that of non-Omicron variant group (P<0. 05). The neutrophil / lymphocyte ratio [(2. 93 (3. 03, 5. 81) vs. 7. 06 (2. 32, 11. 27), P<0. 001], interleukin-2 (IL-2) and interleukin-6 (IL-6) levels in Omicron variant group were significantly lower than those in non-Omicron variant group (P<0. 01). Cardiac troponin I (cTnI) was negative in Omicron variant group, and the concentrations of cTnI, creatine kinase-MB isozyme (CK-MB) and N-terminal pro-brain natriuretic peptide (NT-proB-NP) and the proportion of patients with elevated levels were significantly lower than those of non-Omicron variant group (P<0. 01). The incidence of abnormal electrocardiogram in Omicron variant group was also significantly lower than that in non-Omicron variant group (25. 0% vs. 42. 0%, P = 0. 001), sinus tachycardia, atrial premature beats and T wave changes were the main symptoms. Atrial premature beats, T wave changes, ST segment depression and bundle branch block were the main symptoms in non-Omicron variant group. Conclusions The patients infected with SARS-CoV-2 Omicron variant in Zhuhai may not have obvious myocardial damage because most of the patients have been vaccinated with COVID-19 vaccine. The incidence of abnormal electrocardiogram is also significantly lower than that of non-Omicron variant group, mainly sinus tachycardia, atrial premature beats and T wave changes. © 2022, Editorial Office of Chinese Journal of Arteriosclerosis. All rights reserved.

Integration of neural network and distance relay to improve the fault localization on transmission lines

Power transmission lines are integral and very important components of power systems. Because of the length of these lines and the complexity of the power grids, the lines may encounter various incidents such as lightning strike, shortage, and breakage. When an incident or a fault occurs, a fast process of identification, localization, and isolation of the fault is desired. An accurate fault localization would have a great impact in reducing the restoration time of the system. One of the most popular solutions for fault detection and localization is the distance relays using the impedance-based algorithms. However, these relays are still not perfect with nonzero errors of the fault locations. This paper will present a new approach using the neural networks in addition to a distance relays to correct the fault location estimation of the relay. The solution will be based only on the voltage and current signals measured at the beginning of the lines. The training samples' signals of the transient states on the lines are generated using ATP/EMTP, and then regenerated into the relay tester Omicron CMC-356 to test with the real Siemens 7SA522 relay to improve its fault location results. The numerical results will show that the solution had helped to reduce the average fault location error from 0.92% to 0.42% for 4 types of shortage faults on the lines. [ FROM AUTHOR] Copyright of Turkish Journal of Electrical Engineering & Computer Sciences is the property of Scientific and Technical Research Council of Turkey and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Population-Based Model of the Fraction of Incidental COVID-19 Hospitalizations during the Omicron BA.1 Wave in the United States

1. Background: Some reports have suggested that as many as one-half of all hospital inpatients identified as COVID-19-positive during the Omicron BA.1 variant-driven wave were incidental cases admitted primarily for reasons other than their viral infections. To date, however, there are no prospective longitudinal studies of a representative panel of hospitals based on pre-established criteria for determining whether a patient was, in fact, admitted as a result of the disease. 2. Materials and Methods: To fill this gap, we developed a formula to estimate the fraction of incidental COVID-19 hospitalizations that relies on measurable, population-based parameters. We applied our approach to a longitudinal panel of 164 counties throughout the United States, covering a 4-week interval ending in the first week of January 2022. 3. Results: Within this panel, we estimated that COVID-19 incidence was rising exponentially at a rate of 9.34% per day (95% CI, 8.93–9.87). Assuming that only one-quarter of all Omicron BA.1 infections had been reported by public authorities, we further estimated the aggregate prevalence of active SARS-CoV-2 infection during the first week of January to be 3.45%. During the same week, among 250 high-COVID-volume hospitals within our 164-county panel, an estimated one in four inpatients was COVID-positive. Based upon these estimates, we computed that 10.6% of such COVID-19-positive hospitalized patients were incidental infections. Across individual counties, the median fraction of incidental COVID-19 hospitalizations was 9.5%, with an interquartile range of 6.7 to 12.7%. 4. Conclusion: Incidental COVID-19 infections appear to have been a nontrivial fraction of all COVID-19-positive hospitalized patients during the Omicron BA.1 wave. In the aggregate, however, the burden of patients admitted for complications of their viral infections was far greater. [ FROM AUTHOR] Copyright of COVID is the property of MDPI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

EVOLVING CHARACTERISTICS OF COVID-19 INPATIENTS AT AN AUSTRALIAN CENTRE

Since the declaration of the global pandemic in March 2020, the novel coronavirus disease (COVID-19) has caused dynamic pressures on healthcare systems worldwide. This study aims to compare the demographic and clinical characteristics, management, and outcomes of patients with COVID-19 at a single centre in Sydney, Australia. Using the clinical coding data, we identified all patients aged > 16 years admitted to our centre between February 1st, 2020, and March 31st, 2022. We categorised the time periods 'pre-delta' (February 1st, 2020 – June 15th, 2021), 'delta' (June 16th, 2021 – November 25th, 2021), and 'omicron' (November 26th, 2021 – March 31st, 2022). We retrospectively extracted the demographic, administrative, and clinical data from the electronic medical records and performed a descriptive analysis of the data. A total of 1842 patients were identified (pre-delta N=18;delta N=788;omicron N=1036). The percentage of male patients was 83%, 54%, and 56% and the median ages at admission were 55, 49, and 70 years during the pre-delta, delta, and omicron periods, respectively. The median length of hospital stay was the longest during the pre-delta period (8.5 days vs. 7 vs. 6). ICU admission rate was 39%, 21%, and 10% for each period and of the ICU-admitted patients 43%, 40%, and 36% respectively required mechanical ventilation. Inhospital mortality was the highest during the omicron period (pre-delta inhospital mortality 5.6%;delta 4.1%;omicron 7.3%). A total of 219 (28%) patients of delta and 185 (18%) of omicron periods received at least one dose of dexamethasone and 175 (22%) and 44 (4.2%) respectively received at least one dose of remdesivir. The demographic and clinical characteristics of admitted COVID-19 patients varied across the 'pre-delta', 'delta', and 'omicron' time periods. The median age at admission and in-hospital mortality was the highest during the omicron period. [ FROM AUTHOR] Copyright of International Journal of Infectious Diseases is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Study On The Mechanism Of Panic Buying Under Omicron Virus Impact

China has shown strong social cohesion and epidemic prevention and control actions in the face of the sudden new crown epidemic. This study uses questionnaire survey (N=208) data to investigate the important role of group factors and individual anxiety as mediating variables in the panic buying of the new crown epidemic through an empirical study. It was found that group factors significantly and positively influenced panic buying and individual anxiety significantly and positively influenced panic buying;government control significantly influenced panic buying through the mediating effect of group factors and individual anxiety. By exploring the mechanism of government control on panic buying and the role of group factors and individual anxiety as mediating variables, the study proposes thoughts on the way government control is guided in public crisis events. Government control is a policy risk, which affects individual anxiety through group factors and thus panic buying, and panic buying can lead to scarcity of goods and thus market risk. [ FROM AUTHOR] Copyright of Journal of Pharmaceutical Negative Results is the property of ResearchTrentz and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Clinical characteristics and high-resolution computed tomography findings of 805 patients with mild or moderate infection from SARS-CoV-2 Omicron subvariant BA.2.

BACKGROUND: COVID-19 is a global pandemic. Currently, the predominant strain is SARS-CoV-2 Omicron subvariant BA.2 in many countries. Understanding its infection characteristics can facilitate clinical management. OBJECTIVES: This study aimed to characterize the clinical, laboratory, and high-resolution computed tomography (HRCT) findings in patients with mild or moderate infection from SARS-CoV-2 Omicron subvariant BA.2. METHODS: We performed a retrospective study on patients infected with SARS-CoV-2 Omicron subvariant BA.2 between April 4th and April 17th, 2022. The clinical characteristics, laboratory features, and HRCT images were reviewed. RESULTS: A total of 805 patients were included (411 males and 394 females, median age 33 years old). The infection was mild, moderate, severe, and asymptomatic in 490 (60.9%), 37 (4.6%), 0 (0.0%), and 278 (34.5%) patients, respectively. Notably, 186 (23.1%), 96 (11.9%), 265 (32.9%), 11 (3.4%), 7 (0.9%), and 398 (49.4%) patients had fever, cough, throat discomfort, stuffy or runny nose, fatigue, and no complaint, respectively. Furthermore, 162 (20.1%), 332 (41.2%), and 289 (35.9%) patients had decreased white blood cell counts, reduced lymphocytes, and elevated C-reactive protein levels, respectively. HRCT revealed pneumonia in 53 (6.6%) patients. The majority of the lung involvements were ground-glass opacity (50, 94.3%) mostly in the subpleural area. The grade of lung injury was mainly mild (90.6%). Short-term follow-ups showed that most patients with pneumonia recovered. CONCLUSION: Most patients with mild or moderate infection from SARS-CoV-2 Omicron subvariant BA.2 were adults, with fever and upper respiratory symptoms as the main clinical presentations. Lower respiratory infection was mild, with ground-glass opacity in the subpleural area as the main finding.

The development of statistical literacy among students: Analyzing messages in media articles with Gal's worry questions

Real‐world data are fundamental to modern teaching methodologies that aim to improve statistical knowledge and reasoning in students. Statistical information is encountered in everyday life, such as media articles and involves real‐world contexts. However, information could be biased or (mis)represented and students should be concerned about the validity of such articles, as well as the nature and trustworthiness of the evidence presented, while considering alternative interpretations of the findings conveyed to them. Statistics educators could make use of media articles to create opportunities for students to reflect on such (mis)representations and build statistical literacy. The purpose of this article is to show how information and data on the Omicron COVID‐19 variant have been (mis)represented in the media and by government entities. I also demonstrate how these examples may be utilized in the statistics classroom as they relate to concepts covered in most basic statistics courses. [ FROM AUTHOR] Copyright of Teaching Statistics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Duration of viable virus shedding and polymerase chain reaction positivity of the SARS-CoV-2 Omicron variant in the upper respiratory tract: a systematic review and meta-analysis.

OBJECTIVES: To assess the duration of viable virus shedding and polymerase chain reaction (PCR) positivity of the SARS-CoV-2 Omicron variant in the upper respiratory tract. METHODS: We systematically searched PubMed, Cochrane, and Web of Science for original articles reporting the duration of viable virus shedding and PCR positivity of the SARS-CoV-2 Omicron variant in the upper respiratory tract from November 11, 2021 to December 11, 2022. This meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was registered with PROSPERO (CRD42022357349). We used the DerSimonian-Laird random-effects meta-analyses to obtain the pooled value and the 95% confidence intervals. RESULTS: We included 29 studies and 230,227 patients. The pooled duration of viable virus shedding of the SARS-CoV-2 Omicron variant in the upper respiratory tract was 5.16 days (95% CI: 4.18-6.14), and the average duration of PCR positivity was 10.82 days (95% CI: 10.23-11.42). The duration of viable virus shedding and PCR positivity of the SARS-CoV-2 Omicron variant in symptomatic patients was slightly higher than that in asymptomatic patients, but the difference was not significant (P >0.05). CONCLUSION: The current study improves our understanding of the status of the literature on the duration of viable virus shedding and PCR positivity of Omicron in the upper respiratory tract. Our findings have implications for pandemic control strategies and infection control measures.

Severity of SARS-CoV-2 Omicron variant infection in heart transplant recipients.

SARS-CoV-2 Omicron variant was first detected in France mid-November 2021 in wastewater treatment plants while cases started to increase at the beginning of December. The maximum incidence occurred in mid-January 2022. The Omicron wave spread rapidly throughout France in general population with lower case-fatality rate compared with previous waves. Little is known about infection with Omicron variant in heart transplant (HT) recipients. In this study, we examined incidence and mortality rate of COVID-19 in the general population and among 1,263 HT recipients during the period from June, 2021 to February, 2022, described characteristics of HT recipients infected with SARS-CoV-2 during Omicron (December 1st, 2021-February 7, 2022) and Delta (June 1st- November 30, 2021) periods, and compared hospital course of HT recipients with Omicron and Delta variant infection. Our findings contrast with the reported lower severity for Omicron variant infection compared with Delta variant infection in immunocompetent individuals.

Estimating the serial intervals of SARS-CoV-2 Omicron BA.4, BA.5, and BA.2.12.1 variants in Hong Kong.

Empirical evidence on the epidemiological characteristics of the emerged SARS-CoV-2 variants could shed light on the transmission potential of the virus and strategic outbreak control planning. In this study, by using contact tracing data collected during an Omicron-predominant epidemic phase in Hong Kong, we estimated the mean serial interval of SARS-CoV-2 Omicron BA.4, BA.5, and BA.2.12.1 variants at 2.8 days (95% credible interval [CrI]: 1.5, 6.7), 2.7 days (95% CrI: 2.1, 3.6), and 4.4 days (95% CrI: 2.6, 7.5), respectively, with adjustment for right truncation and sampling bias. The short serial interval for the current circulating variant indicated that outbreak mitigations through contact tracing and case isolation would be quite challenging.

Clinical Characteristics and Outcomes of Children With SARS-CoV-2 Infection During the Delta and Omicron Variant-Dominant Periods in Korea.

BACKGROUND: Data on the clinical characteristics of pediatric patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant infection are limited. We aimed to evaluate the clinical features and outcomes of children with SARS-CoV-2 infection before and after omicron variant dominance in Korea. METHODS: A multicenter retrospective cohort study was conducted in hospitalized patients aged ≤ 18 years with laboratory-confirmed SARS-CoV-2 infection at five university hospitals in South Korea. The study periods were divided into the delta (from August 23, 2021 to January 2, 2022) and omicron (from January 30 to March 31, 2022). RESULTS: In total, 612 hospitalized patients were identified (211, delta; 401, omicron). During the omicron and delta periods, the proportions of individuals with serious illness (moderate, severe, and critical severity) were 21.2% and 11.8%, respectively (P = 0.034). Compared with the delta period, the proportions of patients with moderate illness increased significantly in the age groups of 0-4 years (14.2% vs. 3.4%) and 5-11 years (18.6% vs. 4.2%) during the omicron period. During the two periods, the proportions of patients with complex chronic diseases (delta, 16.0% vs. 4.3%, P = 0.040; omicron, 27.1% vs. 12.7%; P = 0.002), respiratory diseases except for asthma (delta, 8.0% vs. 0.0%, P = 0.013; omicron, 9.4% vs. 1.6%; P = 0.001), and neurologic diseases (delta, 28.0% vs. 3.2%, P < 0.001; omicron, 40.0% vs. 5.1%, P < 0.001) were significantly higher in patients with serious illness than in those with non-serious illness. During the delta period, the risk for serious illness was higher among patients with obesity (adjusted odds ratio [aOR], 8.18; 95% confidence interval [CI], 2.80-27.36) and neurologic diseases (aOR, 39.43; 95% CI, 6.90-268.3) and aged 12-18 years (aOR, 3.92; 95% CI, 1.46-10.85). However, the presence of neurologic disease (aOR, 9.80; 95% CI, 4.50-22.57) was the only risk factor for serious illness during the omicron period. During the omicron period, the proportions of patients with croup (11.0% vs. 0.5%) and seizures (13.2% vs. 2.8%) increased significantly compared with the delta period. CONCLUSION: Compared with the delta period, the proportions of young children and patients with complex comorbidities were higher during the omicron period in Korea. Patients with complex chronic diseases, especially neurologic diseases, had a high risk of severe coronavirus disease 2019 in the two distinct variant-dominant periods.

Development and validation of a prognostic model based on immune variables to early predict severe cases of SARS-CoV-2 Omicron variant infection.

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant has prevailed globally since November 2021. The extremely high transmissibility and occult manifestations were notable, but the severity and mortality associated with the Omicron variant and subvariants cannot be ignored, especially for immunocompromised populations. However, no prognostic model for specially predicting the severity of the Omicron variant infection is available yet. In this study, we aim to develop and validate a prognostic model based on immune variables to early recognize potentially severe cases of Omicron variant-infected patients. Methods: This was a single-center prognostic study involving patients with SARS-CoV-2 Omicron variant infection. Eligible patients were randomly divided into the training and validation cohorts. Variables were collected immediately after admission. Candidate variables were selected by three variable-selecting methods and were used to construct Cox regression as the prognostic model. Discrimination, calibration, and net benefit of the model were evaluated in both training and validation cohorts. Results: Six hundred eighty-nine of the involved 2,645 patients were eligible, consisting of 630 non-ICU cases and 59 ICU cases. Six predictors were finally selected to establish the prognostic model: age, neutrophils, lymphocytes, procalcitonin, IL-2, and IL-10. For discrimination, concordance indexes in the training and validation cohorts were 0.822 (95% CI: 0.748-0.896) and 0.853 (95% CI: 0.769-0.942). For calibration, predicted probabilities and observed proportions displayed high agreements. In the 21-day decision curve analysis, the threshold probability ranges with positive net benefit were 0~1 and nearly 0~0.75 in the training and validation cohorts, correspondingly. Conclusions: This model had satisfactory high discrimination, calibration, and net benefit. It can be used to early recognize potentially severe cases of Omicron variant-infected patients so that they can be treated timely and rationally to reduce the severity and mortality of Omicron variant infection.

Clinical characteristics of patients infected with novel coronavirus wild strain, Delta variant strain and Omicron variant strain in Quanzhou: A real‑world study

This study aimed to investigate the clinical features of patients infected with novel coronavirus wild strains, Delta variant strains and Omicron variant strains to provide a reference for early clinical diagnosis and prognostic assessment. The demographic, clinical symptoms and ancillary examination data of 47 patients with novel coronavirus wild type strain infection, 18 with Delta variant infection and 20 with Omicron variant infection admitted to the First Hospital of Quanzhou affiliated with Fujian Medical University were collected and analyzed. The novel coronavirus wild strain and Delta strain were the predominant clinical types;patients infected with the Omicron strain were mainly asymptomatic. Fever and fatigue were the main clinical manifestations in the wild strain and Delta strain groups, whereas dry cough, nasal congestion, sore throat and fever were common clinical manifestations in the Omicron strain group. The Delta strain and Omicron variant groups had fewer comorbidities than the wild-type strain group, but no significant reduction was observed in the negative conversion time of nucleic acids. Significant differences were found in the neutrophil count/lymphocyte count ratio, lymphocyte count, eosinophil count, red blood cell count, hemoglobin level, erythrocyte sedimentation rate, C-reactive protein, prothrombin time, international normalized ratio and plasma D-dimer, PH, PaO2, lactic acid and albumin levels among the three groups. Patients infected with the Omicron strain in Quanzhou presented with mild symptoms of the upper respiratory tract as the primary clinical manifestation and had few comorbidities and a good prognosis;however, the negative conversion time of the new coronavirus nucleic acid was still considerably long. [ FROM AUTHOR] Copyright of Experimental & Therapeutic Medicine is the property of Spandidos Publications UK Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Why Xi Jinping Reversed His Zero-Covid Policy in China

The rare display of public anger, with some protesters directly criticizing Mr. Xi and the Communist Party, alarmed Mr. Xi and his inner circle, the officials and advisers said. Keywords: leder;wsjworld;photo-news;Political/General News;Respiratory Tract Diseases;Global/World Issues;Health;Medical Conditions;Outbreaks/Epidemics;Politics/International Relations EN leder wsjworld photo-news Political/General News Respiratory Tract Diseases Global/World Issues Health Medical Conditions Outbreaks/Epidemics Politics/International Relations N.PAG N.PAG 1 01/11/23 20230105 NES 230105 A wave of protests coupled with urgent pleas from many corners of the government finally prodded the leader to scrap the strict lockdown system he had touted throughout the pandemic BEIJING - By the end of an otherwise triumphant Communist Party Congress for Xi Jinping in October, it was growing harder for China's leader to argue that his zero-Covid policy was working. [Extracted from the article] Copyright of Wall Street Journal (Online) is the property of Dow Jones & Company Inc and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Algorithmic Solidarity

Both Yao and Zhao hailed the role of technology in addressing the medication shortage. According to Xinhua News Agency, many pharmaceutical companies in China are working at full capacity to produce analgesics, antipyretics, as well as other over-the-counter medicines to treat COVID-19 symptoms. Additionally, the platform will add reminders and guidelines related to safe medication and try to contact suppliers, hoping to provide users with more medication choices, Tencent added. [Extracted from the article] Copyright of Beijing Review is the property of Beijing Review and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

'Party Down' Parties On

Garner, grinning, describes the banter among Scott, Marino, and the rest of the returning cast as "kind of a good-natured abuse, like the little-kid joy of being back together." Back in the early 2000s, Enbom, Rudd, and their TV-producer friends Rob Thomas and Dan Etheridge would gather regularly for what Etheridge describes as "high movie nights at Rob's house." The Mix ON A SUNNY WINTER morning on a Malibu cliff overlooking the Pacific, a luau for radio-contest winners is in full swing. [Extracted from the article] Copyright of Rolling Stone is the property of Rolling Stone LLC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Health Matters

"The experience of the past year has taught us that chasing these Omicron variants with a bivalent vaccine is a losing game", says Offit, who also developed the rotavirus vaccine and is director of the vaccine- education center at the Children's Hospital of Philadelphia. When the pandemic began, and people had no immunity to the virus, building that immunity with vaccines and booster shots was critical. IN THE THIRD YEAR OF THE COVID- 19 pandemic, it may be time to rethink booster recommendations, says one vaccine expert who serves on the U.S. Food and Drug Administration's vaccine advisory committee. [Extracted from the article] Copyright of TIME Magazine is the property of TIME USA, LLC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)