BACKGROUND: Over 65 million people have long COVID. Evidence for using Chinese herbal medicine (CHM) to treat long COVID is growing. A systematic review of evidence for guiding clinical decision is warranted. OBJECTIVE: To examine the effects and safety of CHM in alleviating the severity of dyspnea, fatigue, exercise intolerance, depression, anxiety and insomnia in long COVID adults based on registered randomized clinical trials (RCT). SEARCH STRATEGY: World Health Organization International Clinical Trials Registry Platform and Chinese Clinical Trial Registry were searched for registered trial protocols from database inception to February 10, 2023. English (PubMed, Embase, AMED and CINAHL) and Chinese databases (CNKI, Wanfang Data and CQVIP) were then searched to identify relevant publications from December 2019 through April 6, 2023. INCLUSION CRITERIA: Registered RCTs that compared the effects of Chinese herbal medicines or Chinese herbal formulas against a control treatment (i.e., the placebo or usual care) in adults with persistent symptoms of long COVID. The primary outcome of dyspnea, and secondary outcomes of fatigue, exercise intolerance, depression, anxiety and insomnia were measured using validated tools at the end of the treatment. DATA EXTRACTION AND ANALYSIS: Data were extracted, and eligible RCTs were evaluated using version 2 of the Cochrane risk-of-bias tool for randomized trials and Grading of Recommendations, Assessment, Development and Evaluations independently by two researchers. Effect sizes were estimated by random-effects modelling and mean difference (MD). Heterogeneity between trials was quantified by I². RESULTS: Among the 38 registered clinical trials we identified, seven RCTs (1,519 patients) were included in the systematic review. One RCT had a low overall risk of bias. Compared to the control, CHM reduces dyspnea on the Borg Dyspnea Scale score (MD = -0.2, 95% confidence interval [CI] = -0.65 to 0.25) with moderate certainty, and reduces fatigue on the Borg Scale (MD = -0.48, 95% CI = -0.74 to -0.22) with low certainty. CHM clinically reduces depression on Hamilton Depression Rating Scale score (MD = -6.00, 95% CI = -7.56 to -4.44) and anxiety on Hamilton Anxiety Rating Scale score (MD = -6.10, 95% CI = -7.67 to -4.53), and reduces insomnia on the Insomnia Severity Index (MD = -4.86, 95% CI = -12.50 to 2.79) with moderate certainty. Meta-analysis of two RCTs (517 patients) showed that CHM clinically improves exercise intolerance by increasing 6-minute walking distance (MD = -15.92, 95% CI = -10.20 to 42.05) with substantial heterogeneity (I² = 68%) and low certainty. CONCLUSION CHM is associated with a post-treatment clinical reduction in depression and anxiety in long COVID adults, compared to the control, but it does not have a strong treatment effect on dyspnea and insomnia. Effects of CHM on exercise intolerance and fatigue are uncertain, and the safety of using CHM remains questionable. Please cite this article as: Tsang MS, Zhou IW, Zhang AL, Xue CC. Chinese herbal medicine for dyspnea and persistent symptoms of long COVID: A systematic review and meta-analysis of randomized controlled trials. J Integr Med. 2025; 23(2): 126-137.
Humans ; Dyspnea/etiology* ; Drugs, Chinese Herbal/therapeutic use* ; Randomized Controlled Trials as Topic ; COVID-19/complications* ; Fatigue/drug therapy* ; SARS-CoV-2 ; Anxiety/drug therapy* ; Depression/drug therapy* ; Sleep Initiation and Maintenance Disorders/drug therapy* ; Betacoronavirus

OBJECTIVE: Coronavirus disease 2019 (COVID-19) can result in fatigue and post-exertional malaise; however, whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection exacerbates lower urinary tract symptoms (LUTS) is unclear. This study investigated the association between prenatal SARS-CoV-2 infection and postpartum LUTS. METHODS: A multicenter, retrospective cohort study was conducted at two tertiary hospitals in China from November 1, 2022, to November 1, 2023. Participants were classified into infected and uninfected groups based on SARS-CoV-2 antigen results. LUTS prevalence and severity were assessed using self-reported symptoms and the Incontinence Impact Questionnaire-Short Form (IIQ-7). Pelvic floor muscle activity was measured using electromyography following the Glazer protocol. Group comparisons were performed to evaluate the association of SARS-CoV-2 infection with LUTS and electromyography parameters, with stratified analyses conducted using SPSS version 26.0. RESULTS: Among 3,652 participants (681 infected, 2,971 uninfected), no significant differences in LUTS prevalence or IIQ-7 scores were observed. However, SARS-CoV-2 infection was an independent factor influencing the electromyographic activity of the pelvic floor muscles (mean tonic contraction amplitudes), regardless of delivery mode ( P = 0.001). CONCLUSION Prenatal SARS-CoV-2 infection was not significantly associated with an increased risk of postpartum LUTS but independently altered pelvic floor muscle electromyographic activity, suggesting potential neuromuscular effects.
Humans ; Female ; COVID-19/epidemiology* ; Retrospective Studies ; Adult ; Pregnancy ; Lower Urinary Tract Symptoms/virology* ; Postpartum Period ; Pregnancy Complications, Infectious/virology* ; China/epidemiology* ; Electromyography ; SARS-CoV-2/physiology* ; Pelvic Floor/physiopathology* ; Prevalence

PURPOSE: The rate of complications among patients undergoing surgery has increased due to infection with SARS-CoV-2 and other variants of concern. However, Omicron has shown decreased pathogenicity, raising questions about the risk of postoperative complications among patients who are infected with this variant. This study aimed to investigate complications and related factors among patients with recent Omicron infection prior to undergoing orthopedic surgery. METHODS: A historical control study was conducted. Data were collected from all patients who underwent surgery during 2 distinct periods: (1) between Dec 12, 2022 and Jan 31, 2023 (COVID-19 positive group), (2) between Dec 12, 2021 and Jan 31, 2022 (COVID-19 negative control group). The patients were at least 18 years old. Patients who received conservative treatment after admission or had high-risk diseases or special circumstances (use of anticoagulants before surgery) were excluded from the study. The study outcomes were the total complication rate and related factors. Binary logistic regression analysis was used to identify related factors, and odds ratio (OR) and 95% confidence interval (CI) were calculated to assess the impact of COVID-19 infection on complications. RESULTS: In the analysis, a total of 847 patients who underwent surgery were included, with 275 of these patients testing positive for COVID-19 and 572 testing negative. The COVID-19-positive group had a significantly higher rate of total complications (11.27%) than the control group (4.90%, p < 0.001). After adjusting for relevant factors, the OR was 3.08 (95% CI: 1.45-6.53). Patients who were diagnosed with COVID-19 at 3-4 weeks (OR = 0.20 (95% CI: 0.06-0.59), p = 0.005), 5-6 weeks (OR = 0.16 (95% CI: 0.04-0.59), p = 0.010), or ≥7 weeks (OR = 0.26 (95% CI: 0.06-1.02), p = 0.069) prior to surgery had a lower risk of complications than those who were diagnosed at 0-2 weeks prior to surgery. Seven factors (age, indications for surgery, time of operation, time of COVID-19 diagnosis prior to surgery, C-reactive protein levels, alanine transaminase levels, and aspartate aminotransferase levels) were found to be associated with complications; thus, these factors were used to create a nomogram. CONCLUSION Omicron continues to be a significant factor in the incidence of postoperative complications among patients undergoing orthopedic surgery. By identifying the factors associated with these complications, we can determine the optimal surgical timing, provide more accurate prognostic information, and offer appropriate consultation for orthopedic surgery patients who have been infected with Omicron.
Humans ; COVID-19/complications* ; Male ; Female ; Middle Aged ; Postoperative Complications/epidemiology* ; SARS-CoV-2 ; Orthopedic Procedures/adverse effects* ; Aged ; Nomograms ; Adult ; Retrospective Studies ; Risk Factors

OBJECTIVE: To analyze the effect of COVID-19 infection on the mobilization and collection of autologous peripheral blood stem cells in patients with multiple myeloma. METHODS: The general baseline data, treatment factors before mobilization collection, collection status, and treatment overview after collection of autologous peripheral blood stem cells at Beijing Chaoyang Hospital affiliated with Capital Medical University from January 1, 2020 to July 15, 2023 were analyzed. RESULTS: 269 patients underwent mobilization and collection of autologous peripheral blood stem cells. Among them, 32 cases with COVID-19 infection history (COVID-19 group) and 237 cases without COVID-19 infection history (non-COVID-19 group). In the COVID-19 group, 17 cases were treated with chemotherapy (etoposide)+G-CSF, and 15 cases were treated with plerixafor +G-CSF. In the non-COVID-19 group, 214 cases were treated with chemotherapy +G-CSF, 17 cases were treated with plerixafor +G-CSF, and 6 cases were treated with chemotherapy + plerixafor +G-CSF. The number of CD34⁺ cells, collection success rate, and excellence rate in the COVID-19 group and the non-COVID-19 group were ［5.52 (0.94-26.87) vs 4.80 (0.53-37.20)］×10⁶/kg (P =0.610), (93.8% vs 85.2%) (P =0.275), (62.5% vs 49.4%) (P =0.190), respectively. Among 113 patients mobilized with etoposide +G-CSF, the number of CD34⁺ cells, success rate, and excellence rate collected from COVID-19 infection (17 cases) and non-COVID-19 infection (96 cases) were ［7.54 (2.66-26.87) vs 7.78 (2.26-37.20)］×10⁶/kg (P =0.847), (100.0% vs 100.0%) (no P value), (82.4% vs 86.5%) (P =0.655), respectively. Among 32 patients mobilized by plerixafor +G-CSF, the number of CD34⁺ cells, success rate and excellence rate of COVID-19 infection (15 cases) and non-COVID-19 infection (17 cases) were ［3.82 (0.94-7.27) vs 4.11 (0.53-9.05)］×10⁶/kg (P =0.821), (86.7% vs 88.2%) (P =0.893), (40.0% vs 35.3%) (P =0.784), respectively. In 32 patients with COVID-19 infection, the number of CD34⁺ cells collected by etoposide +G-CSF (17 cases) and plerixafor +G-CSF (15 cases), as well as the success rate and excellence rate were ［7.54 (2.66-26.87) vs 3.82(0.94-7.27)］×10⁶/kg (P =0.004), (100.0% vs 86.7%) (P =0.120), (82.4% vs 40.0%) (P =0.014), respectively. By 2023.7.31, 232 patients (86.2%, 232/269) had received transplantation, including 24 patients in the COVID-19 group and 208 patients in the non-COVID-19 group. The median number of CD34⁺ cells infused in the two groups was ［3.67 (2.50-13.44) vs 3.11(1.12-19.89)］×10⁶/kg (P =0.058), the median days of neutrophil engraftment ［11(9-13) vs 11(9-17)］ (P =0.674), the median days of platelet engraftment ［11(0-23), 12(0-43)］ (P =0.279), respectively. CONCLUSION The history of COVID-19 infection did not affect the PBSC mobilization, collection and transplantation of patients with myeloma. In patients with COVID-19 infection, the results of chemotherapy mobilization with etoposide seems to be better than that of plerixafor mobilization, but further research is needed to clarify.
Humans ; COVID-19/complications* ; Multiple Myeloma/complications* ; Hematopoietic Stem Cell Mobilization ; Transplantation, Autologous ; Granulocyte Colony-Stimulating Factor/therapeutic use* ; Peripheral Blood Stem Cell Transplantation ; SARS-CoV-2 ; Middle Aged ; Peripheral Blood Stem Cells ; Male ; Female ; Cyclams ; Benzylamines

The pandemic of coronavirus disease 2019 (COVID-19) has impacted our lifestyles. On the one hand, the patients with hematological malignancies (HM) are more vulnerable to COVID-19 infection. Once infected with COVID-19, these patients tend to develop into severe type with a higher mortality rate. Although patients with HM demonstrated a reduced response to COVID-19 vaccines, they still can benefit from vaccine injection with reduced rates of viral infection and incidence of severe cases. The combination of monoclonal antibodies and antiviral drugs is helpful to the COVID-19 treatment of patients with HM. On the other hand, COVID-19 infection can lead to a delay of hematopoietic recovery and low immunity in patients with HM. For HM patients with COVID-19 infection, to reduce the intensity and shorten the course of radiotherapy and chemotherapy is needed. This article will review the interaction between COVID-19 infection and HM.
Humans ; COVID-19/complications* ; Hematologic Neoplasms/complications* ; SARS-CoV-2

OBJECTIVE: To retrospectively analyze the characteristics and influencing factors of COVID-19 infection in patients with multiple myeloma (MM) who underwent autologous hematopoietic stem cell transplantation (AHSCT). METHODS: The clinical data of MM patients who underwent AHSCT in Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from May 26, 2021 to December 26, 2022 were collected. The onset of COVID-19 infection, corresponding symptoms and laboratory tests were followed up in outpatient or by the means of telephone contact and online questionnaires. Related analysis was then performed. RESULTS: This study included 96 patients, and 72 cases among them were infected with COVID-19 while 24 cases were uninfected. Logistic regression analysis showed that vaccination did not significantly reduce the risk of COVID-19 infection, but patients who received two doses of the vaccine had a lower risk of developing moderate and severe disease than those who did not receive or received one dose (OR =0.06, P =0.029). Patients who received daratumumab before had a higher risk of COVID-19 infection (OR =5.78, P =0.039), while those with a history of immunomodulatory drugs (IMiDs) had the opposite effect (OR =0.31, P =0.028). The use of both drugs did not affect the severity of COVID-19 infection. CONCLUSION For MM patients undergoing AHSCT as first-line chemotherapy, COVID-19 vaccination does not significantly reduce the infection rate, but it plays a role in preventing moderate and severe cases. The application of antineoplastic drugs with different mechanisms has a certain impact on the susceptibility to the COVID-19, which should be considered comprehensively when creating treatment plans.
Humans ; Multiple Myeloma/complications* ; COVID-19/epidemiology* ; Hematopoietic Stem Cell Transplantation ; Transplantation, Autologous ; Retrospective Studies ; Risk Assessment ; Risk Factors ; Male ; Female ; Middle Aged ; SARS-CoV-2 ; Adult ; Antibodies, Monoclonal

BACKGROUND: The long-term impact of symptom classification on quality of life (QOL) and economic outcomes among individuals with long coronavirus disease (COVID) remains poorly understood. This study aimed to clarify the situation of long COVID in Japan by analyzing patients using cluster classification. METHODS: This multicenter, retrospective cohort study enrolled 515 patients with COVID-19 and followed up for 36 months via standardized questionnaires. Patients were classified based on: 1) symptom trajectory over time and 2) symptom cluster profiles at 3 months. RESULTS: While the number of symptoms decreased, fatigue and dyspnea frequently persisted, whereas anosmia and dysgeusia declined. Cough and sputum decreased gradually. The proportion of patients with 5-9 symptoms increased. The mean (interquartile range) presenteeism scores were lower in the continuous (60 [50-80]) and relapse groups (65 [48-80]) than in the recovered group (70 [50-80]). The multiple symptoms cluster had the worst SF-36, presenteeism, and absenteeism scores (47.2 [44.7-49.8], 48.8 [27.5-72.5], and 10.9 [0.0-11.0], respectively). CONCLUSIONS Patients with continuous and multiple symptoms experienced persistently lower QOL and greater economic burden up to 36 months after COVID-19 diagnosis. The long-term effects of long COVID are not only physical but also mental and economical. Thus, further research is needed to clarify the economical and physiological impact of long COVID.
Adult ; Aged ; Aged, 80 and over ; Female ; Humans ; Male ; Middle Aged ; COVID-19/complications* ; Japan/epidemiology* ; Post-Acute COVID-19 Syndrome/psychology* ; Quality of Life ; Retrospective Studies ; Surveys and Questionnaires ; East Asian People

INTRODUCTION: Outcomes after SARS-CoV-2 Omicron infection in patients with heart failure (HF) and ischaemic heart disease (IHD) remain poorly defined. METHOD: In a highly vaccinated cohort of adult Singapore citizens and permanent residents, we used Cox proportional hazards models (adjusted for sociodemographic variables and comorbidities) to compare the risks of Omicron infection, COVID-19- related hospitalisation, and severe COVID-19 between indivi-duals with HF or IHD and matched controls without these conditions. RESULTS: From national databases, we identified 15,426 HF patients matched 1:∼3 to 41,221 controls, and 110,442 IHD patients matched 1:∼2 to 223,843 controls. Over 80% of HF and IHD patients had received at least 3 vaccine doses. During the Omicron-predominant period, both HF and IHD cohorts demonstrated higher adjusted risks of COVID-19 hospitalisation compared with matched controls (HF: adjusted hazard ratio [aHR] 1.77, 95% confidence interval [CI] 1.65-1.90; IHD: aHR 1.21, 95% CI 1.17-1.26). Among those with at least 1 HF-or IHD-related admission in the prior year, hospitalisation risk was further elevated (HF: aHR 1.27, 95% CI 1.13-1.42; IHD: aHR 1.11, 95% CI 1.01-1.23). Receipt of ≥3 vaccine doses was associated with substantially lower risk of severe COVID-19 versus only 2 doses (HF: aHR 0.35, 95% CI 0.28-0.43; IHD: aHR 0.27, 95% CI 0.23-0.32). A fourth dose conferred additional reductions in infection and adverse outcomes, though CIs for infection overlapped with those for 3 doses. CONCLUSION During Omicron predominance, HF and IHD patients experienced greater risk of COVID-19 hospitalisation and severe COVID-19 versus matched controls. Booster vaccinations attenuated these risks. Individuals with recent HF/IHD admissions should be prioritised for receipt of booster vaccine doses.
Humans ; COVID-19/complications* ; Male ; Heart Failure/complications* ; Myocardial Ischemia/complications* ; Female ; Middle Aged ; Hospitalization/statistics & numerical data* ; Aged ; COVID-19 Vaccines/administration & dosage* ; Singapore/epidemiology* ; SARS-CoV-2 ; Proportional Hazards Models ; Adult ; Case-Control Studies ; Vaccination/statistics & numerical data*

BACKGROUND: The outbreak of coronavirus disease 2019 (COVID-19) infection posed a huge threat and burden to public healthcare in late 2022. Non-drug measures of traditional Chinese medicine (TCM), such as acupuncture, cupping and moxibustion, are commonly used as adjuncts in China to help in severe cases, but their effects remain unclear. OBJECTIVES: To observe the clinical effect of TCM non-drug measures in improving respiratory function and symptoms among patients with severe COVID-19. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS: This study was designed as a multicenter, assessor-blind, randomized controlled trial. Hospitalized patients with COVID-19 were randomly assigned to the treatment or control group. The treatment group received individualized TCM non-drug measures in combination with prone position ventilation, while the control group received prone position ventilation only for 5 consecutive days. MAIN OUTCOME MEASURES: The primary outcome measures were the percentage of patients with improved oxygen saturation (SpO₂) at the end of the 5-day intervention, as well as changes of patients' respiratory rates. The secondary outcome measures included changes in SpO₂ and total score on the self-made respiratory symptom scale. The improvement rate, defined as a 3-day consecutive increase in SpO₂, the duration of prone positioning, and adverse events were recorded as well. RESULTS: Among the 198 patients included in the intention-to-treat analysis, 159 (80.3%) completed all assessments on day 5, and 39 (19.7%) patients withdrew from the study. At the end of the intervention, 71 (91%) patients in the treatment group had SpO₂ above 93%, while 61 (75.3%) in the control group reached this level. The proportion of participant with improved SpO₂ was significantly greater in the intervention group (mean difference [MD] = 15.7; 95% confidence interval [CI]: 4.4, 27.1; P = 0.008). Compared to the baseline, with daily treatment there were significant daily decreases in respiratory rates in both groups, but no statistical differences between groups were found (all P ≥ 0.05). Compared to the control group, the respiratory-related symptoms score was lower among patients in the treatment group (MD = -1.7; 95% CI: -2.8, -0.5; P = 0.008) after day 3 of treatment. A gradual decrease in the total scores of both groups was also observed. Thirty-one adverse events occurred during the intervention, and 2 patients were transferred to the intensive care unit due to deterioration of their illness. CONCLUSION: TCM non-drug measures combined with prone positioning can effectively treat patients with severe COVID-19. The combined therapy significantly increased SpO₂ and improved symptom scores compared to prone positioning alone, thus improving the patients' respiratory function to help them recover. However, the improvement rate did not differ between the two groups. TRIAL REGISTRATION Chinese Clinical Trial Registry (ChiCTR2300068319). Please cite this article as: Yin X, Jin Z, Li F, Huang L, Hu YM, Zhu BC, Wang ZQ, Li XY, Li JP, Lao LX, Mi YQ, Xu SF. Effectiveness and safety of adjunctive non-drug measures in improving respiratory symptoms among patients with severe COVID-19: A multicenter randomized controlled trial. J Integr Med. 2024; 22(6): 637-644.
Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Acupuncture Therapy/methods* ; China ; COVID-19/complications* ; Medicine, Chinese Traditional/methods* ; Moxibustion/methods* ; Oxygen Saturation ; Prone Position ; Respiration, Artificial ; Treatment Outcome

Objective: This cross-sectional investigation aimed to determine the incidence, clinical characteristics, prognosis, and related risk factors of olfactory and gustatory dysfunctions related to infection with the SARS-CoV-2 Omicron strain in mainland China. Methods: Data of patients with SARS-CoV-2 from December 28, 2022, to February 21, 2023, were collected through online and offline questionnaires from 45 tertiary hospitals and one center for disease control and prevention in mainland China. The questionnaire included demographic information, previous health history, smoking and alcohol drinking, SARS-CoV-2 vaccination, olfactory and gustatory function before and after infection, other symptoms after infection, as well as the duration and improvement of olfactory and gustatory dysfunction. The self-reported olfactory and gustatory functions of patients were evaluated using the Olfactory VAS scale and Gustatory VAS scale. Results: A total of 35 566 valid questionnaires were obtained, revealing a high incidence of olfactory and taste dysfunctions related to infection with the SARS-CoV-2 Omicron strain (67.75%). Females(χ2=367.013, P<0.001) and young people(χ2=120.210, P<0.001) were more likely to develop these dysfunctions. Gender(OR=1.564, 95%CI: 1.487-1.645), SARS-CoV-2 vaccination status (OR=1.334, 95%CI: 1.164-1.530), oral health status (OR=0.881, 95%CI: 0.839-0.926), smoking history (OR=1.152, 95%CI=1.080-1.229), and drinking history (OR=0.854, 95%CI: 0.785-0.928) were correlated with the occurrence of olfactory and taste dysfunctions related to SARS-CoV-2(above P<0.001). 44.62% (4 391/9 840) of the patients who had not recovered their sense of smell and taste also suffered from nasal congestion, runny nose, and 32.62% (3 210/9 840) suffered from dry mouth and sore throat. The improvement of olfactory and taste functions was correlated with the persistence of accompanying symptoms(χ2=10.873, P=0.001). The average score of olfactory and taste VAS scale was 8.41 and 8.51 respectively before SARS-CoV-2 infection, but decreased to3.69 and 4.29 respectively after SARS-CoV-2 infection, and recovered to 5.83and 6.55 respectively at the time of the survey. The median duration of olfactory and gustatory dysfunctions was 15 days and 12 days, respectively, with 0.5% (121/24 096) of patients experiencing these dysfunctions for more than 28 days. The overall self-reported improvement rate of smell and taste dysfunctions was 59.16% (14 256/24 096). Gender(OR=0.893, 95%CI: 0.839-0.951), SARS-CoV-2 vaccination status (OR=1.334, 95%CI: 1.164-1.530), history of head and facial trauma(OR=1.180, 95%CI: 1.036-1.344, P=0.013), nose (OR=1.104, 95%CI: 1.042-1.171, P=0.001) and oral (OR=1.162, 95%CI: 1.096-1.233) health status, smoking history(OR=0.765, 95%CI: 0.709-0.825), and the persistence of accompanying symptoms (OR=0.359, 95%CI: 0.332-0.388) were correlated with the recovery of olfactory and taste dysfunctions related to SARS-CoV-2 (above P<0.001 except for the indicated values). Conclusion: The incidence of olfactory and taste dysfunctions related to infection with the SARS-CoV-2 Omicron strain is high in mainland China, with females and young people more likely to develop these dysfunctions. Active and effective intervention measures may be required for cases that persist for a long time. The recovery of olfactory and taste functions is influenced by several factors, including gender, SARS-CoV-2 vaccination status, history of head and facial trauma, nasal and oral health status, smoking history, and persistence of accompanying symptoms.
Female ; Humans ; Adolescent ; SARS-CoV-2 ; Smell ; COVID-19/complications* ; Cross-Sectional Studies ; COVID-19 Vaccines ; Incidence ; Olfaction Disorders/etiology* ; Taste Disorders/etiology* ; Prognosis