Epidemiological study using IgM and IgG antibody titers against SARS-CoV-2 in The University of Tokyo,Japan (UT-CATS)

IntroductionThe worldwide pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has continued to date. Given that some of the patients with coronavirus disease 2019 (COVID-19) are asymptomatic, antibody tests are useful to determine whether there is a previous infection with SARS-CoV-2. In this study, we measured IgM and IgG antibody titers against SARS-CoV-2 in the serum of asymptomatic healthy subjects in The University of Tokyo, Japan.MethodsFrom June 2020, we recruited participants, who were students, staff, and faculty members of The University of Tokyo in the project named The University of Tokyo COVID-19 Antibody Titer Survey (UT-CATS). Following blood sample collection, participants were required to answer an online questionnaire about their social and health information. We measured IgG and IgM titers against SARS-CoV-2 using iFlash-SARS-CoV-2 IgM and IgG detection kit which applies a chemiluminescent immunoassay (CLIA) for the qualitative detection.ResultsThere were 6609 volunteers in this study. After setting the cutoff value at 10 AU/mL, 32 (0.48%) were positive for IgG and 16 (0.24%) for IgM. Of six participants with a history of COVID-19, five were positive for IgG, whereas all were negative for IgM. The median titer of IgG was 0.40 AU/mL and 0.39 AU/mL for IgM. Both IgG and IgM titers were affected by gender, age, smoking status, and comorbidities.ConclusionsPositive rates of IgG and IgM titers were relatively low in our university. Serum levels of these antibodies were affected by several factors, which might affect the clinical course of COVID-19.     

Therapeutic potential of ciclesonide inhalation for COVID-19 pneumonia: Report of three cases

No specific and effective anti-viral treatment has been approved for COVID-19 so far. Systemic corticosteroid has been sometimes administered to severe infectious diseases combined with the specific treatment. However, as lack of the specific anti-SARS-CoV-2 drug, systemic steroid treatment has not been recommended for COVID-19. We report here three cases of the COVID-19 pneumonia successfully treated with ciclesonide inhalation. Rationale of the treatment is to mitigate the local inflammation with inhaled steroid that stays in the lung and to inhibit proliferation of the virus by antiviral activity. Larger and further studies are warranted to confirm the result of these cases.     

Accuracy of rapid antigen detection test for nasopharyngeal swab specimens and saliva samples in comparison with RT-PCR and viral culture for SARS-CoV-2 detection

IntroductionRapid antigen detection (RAD) tests are convenient tools for detecting the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in clinics, and testing using saliva samples could decrease the risk of infection during sample collection. This study aimed to assess the accuracy of the SARS-CoV-2 RAD for testing of nasopharyngeal swab specimens and saliva samples in comparison with the RT-PCR tests and viral culture for detecting viable virus.MethodsOne hundred seventeen nasopharyngeal swab specimens and 73 saliva samples with positive results on RT-PCR were used. Residual samples were assayed using a commercially available RAD test immediately, and its positivity was determined at various time points during the clinical course. The concordance between 54 nasopharyngeal swab samples and saliva samples that were collected simultaneously was determined. Viral culture was performed on 117 samples and compared with the results of the RAD test.ResultsThe positive rate of RAD test using saliva samples was low throughout the clinical course. Poor concordance was observed between nasopharyngeal swab specimens and saliva samples (75.9%, kappa coefficient 0.310). However, a substantially high concordance between the RAD test and viral culture was observed in both nasopharyngeal swab specimens (86.8%, kappa coefficient 0.680) and saliva samples (95.1%, kappa coefficient 0.643).ConclusionsThe sensitivity of the SARS-CoV-2 RAD test was insufficient, particularly for saliva samples. However, a substantially high concordance with viral culture suggests its potential utility as an auxiliary test for estimating SARS-CoV-2 viability.     

Comparison of clinical characteristics of COVID-19 in pregnant women between the Delta and Omicron variants of concern predominant periods

BackgroundInformation regarding effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant strains on clinical manifestations and outcomes of coronavirus disease 2019 (COVID-19) in pregnant women is limited.MethodsA retrospective observational study was conducted using the data from the nationwide COVID-19 registry in Japan. We identified pregnant patients with symptomatic COVID-19 hospitalized during the study period. The Delta and Omicron variants of concern (VOC) predominant periods were defined as August 1 to December 31, 2021 and January 1 to May 31, 2022, respectively. Clinical characteristics were compared between the patients in the Delta and Omicron VOC periods. In addition, logistic regression analysis was performed to identify risk factors for developing moderate-to-severe COVID-19.ResultsDuring the study period, 310 symptomatic COVID-19 cases of pregnant women were identified; 111 and 199 patients were hospitalized during the Delta and Omicron VOC periods, respectively. Runny nose and sore throat were more common, and fatigue, dysgeusia, and olfactory dysfunction were less common manifestations observed in the Omicron VOC period. In the multivariable logistic regression analysis, onset during the later stage of pregnancy (OR: 2.08 [1.24–3.71]) and onset during the Delta VOC period (OR: 2.25 [1.08–4.90]) were independently associated with moderate-to-severe COVID-19, whereas two doses of SARS-CoV-2 vaccine were protective against developing moderate-to-severe COVID-19 (OR: 0.34 [0.13–0.84]).ConclusionsClinical manifestations of COVID-19 in pregnant women differed between the Delta and Omicron VOC periods. SARS-CoV-2 vaccination was still effective in preventing severe COVID-19 throughout the Delta and Omicron VOC periods.     

TAFRO syndrome with a fatal clinical course following BNT162b2 mRNA (Pfizer-BioNTech) COVID-19 vaccination: A case report

TAFRO syndrome is a rare disorder that manifests as thrombocytopenia, anasarca, fever, reticulin myelofibrosis, renal dysfunction, and organomegaly. Although this disease often follows a severe clinical course, the cause remains unknown. The coronavirus disease 2019 (COVID-19) pandemic is a major global problem. Vaccination against COVID-19 has been successful; however, there are concerns about severe adverse events. Herein, we report a rare presentation of TAFRO syndrome triggered by the COVID-19 vaccine with a fatal clinical course. A 42-year-old Japanese man presented to our hospital complaining of fever lasting for 2 weeks that occurred a day after receiving the BNT162b2 mRNA (Pfizer-BioNTech) COVID-19 vaccine. The patient had a low platelet count, ascites, reticulin myelofibrosis, renal failure, and lymphadenopathy and was diagnosed with TAFRO syndrome. Despite administering several immunosuppressive drugs, the condition did not improve. The patient repetitively developed and eventually died of bacteremia caused by multidrug-resistant Klebsiella pneumoniae. We highlight the first reported case of TAFRO syndrome after COVID-19 vaccination.     

Risk of SARS-CoV-2 Transmission Among Coworkers in a Surgical Environment

Health care workers are at high risk for contracting coronavirus disease 2019. However, little is known about the risk of transmission between coworkers. The objective of this study was to determine the risk of transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between coworkers in a surgical environment. This was an observational study of 394 health care workers in a surgical environment who were exposed to 2 known SARS-CoV-2–positive coworkers. Standard infection precautions were in place at the time of the exposure. All 394 exposed workers initially underwent nasopharyngeal swab testing for SARS-CoV-2 using the polymerase chain reaction technique. Of the original group, 387 were tested again with the same technique 1 week later. Of 394 SARS-CoV-2–exposed health care workers initially tested, 1 was positive. No new positive cases were found on repeated testing of 387 participants 1 week later. The risk of transmission of SARS-CoV-2 in a health care unit with universal masking and appropriate hand hygiene is low. This finding should provide some reassurance to surgical practices as they reopen.     

Critically ill patients with COVID-19 in Tokyo,Japan: A single-center case series

IntroductionWe reported, in our previous study, a patient with coronavirus disease 2019 (COVID-19) who was successfully treated with extracorporeal membrane oxygenation. Data on clinical courses and outcomes of critically ill patients with COVID-19 in Japan are limited in the literature. This study aimed to describe the clinical courses and outcomes of critically ill patients with COVID-19 in Tokyo, Japan.MethodsThis is a single-center case series study. Patients with COVID-19 treated with mechanical ventilation (MV) were reviewed retrospectively. Data on baseline characteristics, in-hospital treatment, and outcomes were collected.ResultsBetween February 2, 2020, and June 30, 2020, 14 critically ill patients with COVID-19 were treated with MV. Most patients were male and had comorbidities, especially hypertension or diabetes; 35.7% were overweight and 21.4% were obese. The majority of the patients had dyspnea on admission. The median duration of MV was 10.5 days, and the 28-day mortality rate was 35.7%. In the four patients with COVID-19 who died, the cause of death was respiratory failure.ConclusionsAs in previous reports from other countries, the mortality rate of patients with COVID-19 requiring intensive care remains high in Tokyo. Further study on the appropriate timing of MV initiation and specific treatments for critically ill patients with COVID-19 is needed.     

Clinical characteristics of COVID-19 in hospitalized children during the Omicron variant predominant period

IntroductionInformation regarding the clinical manifestations and outcomes of coronavirus disease 2019 (COVID-19) in children under the Omicron variant predominant period is still limited.MethodsA nationwide retrospective cohort study was conducted. Pediatric COVID-19 patients (<18 years of age) hospitalized between August 1, 2021 and March 31, 2022 were enrolled. Epidemiological and clinical characteristics between the Delta variant predominant period (August 1 to December 31, 2021) and the Omicron variant predominant period (January 1 to March 31, 2022) were compared.ResultsDuring the study period, 458 cases in the Delta predominant period and 389 cases in the Omicron predominant period were identified. Median age was younger (6.0 vs. 8.0 years, P = 0.004) and underlying diseases were more common (n = 65, 16.7% vs. n = 53, 11.6%) in the Omicron predominant period than those in the Delta variant predominant era. For clinical manifestations, fever ≥38.0 °C at 2 to <13 years old, sore throat at ≥ 13 years, and seizures at 2 to <13 years old were more commonly observed, and dysgeusia and olfactory dysfunction at ≥ 6 years old were less commonly observed in the Omicron variant predominant period. The number of patients requiring noninvasive oxygen support was higher in the Omicron predominant period than that in the Delta predominant period; however, intensive care unit admission rates were similar and no patients died in both periods.ConclusionsIn the Omicron variant predominant period, more pediatric COVID-19 patients experienced fever and seizures, although the overall outcomes were still favorable.     

Safety of and antibody response to the BNT162b2 COVID-19 vaccine in adolescents and young adults with underlying disease

BackgroundData are limited regarding the safety of and antibody response to the BNT162b2 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger ribonucleic acid vaccine in adolescents and young adults with underlying disease.MethodsThis prospective observational study enrolled patients age 12–25 years with chronic underlying disease who received 2 doses of BNT162b2. A 18-item questionnaire was used to assess adverse events within 7 days post-vaccination, and data regarding severe adverse events were collected from electronic medical records. An antibody titer for the receptor-binding domain of the spike protein in SARS-CoV-2 was used to assess antibody response after the second vaccine dose.ResultsStudy participants were 429 patients (241 [56.2%] age 12–15 years; 188 [43.8%] age 16–25 years). The most common underlying diseases were genetic or chromosomal abnormalities and/or congenital anomalies, followed by endocrine or metabolic diseases; 32% of participants were immunocompromised. Severe adverse events were observed after the second dose in 1 (0.4%) patient age 12–15 years and in 2 (1.1%) patients age 16–25 years; all patients recovered. Seropositivity after the second vaccine dose was 99.0%. The geometric mean antibody titer was higher in patients age 12–15 years versus 16–25 years (1603.3 [1321.8–1944.7] U/mL vs. 949.4 [744.2–1211.0] U/mL). Compared with immunocompetent patients, immunocompromised patients had a lower antibody titer (2106.8 [1917.5–2314.7] U/mL vs. 467.9 [324.4–674.8] U/mL).ConclusionsVaccination with BNT162b2 was acceptably safe and immunogenic for adolescents and young adults with underlying disease.     

Prolonged infective SARS-CoV-2 omicron variant shedding in a patient with diffuse large B cell lymphoma successfully cleared after three courses of remdesivir

We report a case of prolonged shedding of the infective SARS-CoV-2 omicron variant BA.1.1.2 in a 79-year-old male patient with diffuse large B-cell lymphoma, after receiving chemotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP). The patient was admitted to our hospital in late March 2022 for the sixth course of R-CHOP chemotherapy. Initially, the patient tested negative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using an in-hospital loop-mediated amplification assay with a nasopharyngeal swab, both on the day of admission and three days later. However, the patient developed fever and was diagnosed with coronavirus disease (COVID-19) six days after admission and was suspected to have contracted the infection in the ward. Viral shedding continued for more than three months, with confirmed viral infectivity. As compared to the original Wuhan-Hu-1/2019 strain, amino acid substitutions including S36 N in non-structural protein (NSP)2, S148P, S1265del and L1266I in NSP3, G105D in NSP4, G496S, A831V, or V987F in spike protein, and I45T in open-reading frame (ORF)9b were randomly detected in isolated viruses. Although the patient had received two doses of the BNT162b2 vaccine approximately six months earlier and the third dose on day 127 after the infection, both serum anti-spike and anti-nuclear protein IgG and IgM tests were negative at day 92, 114, and 149 after the infection. The patient finally cleared the virus after the third course of remdesivir and did not have further recurrence.     

A case report of breakthrough infection with the SARS-CoV-2 delta variant and household transmission: Role of vaccination,anti-spike IgG and neutralizing activity

There have been several reports of breakthrough infections, which are defined as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections among individuals who had received at least two doses of vaccine at least 14 days before the onset of infection, but data on the antibody titers, including SARS-CoV-2 neutralizing antibody activity, and the clinical course of individuals with breakthrough infections are limited. We encountered a case of breakthrough infection with the SARS-CoV-2 delta variant in a 31-year-old female healthcare worker (the index case, Case 1) and a secondary case (Case 2) in her unvaccinated 33-year-old husband. We studied the role of the anti-spike immunoglobulin G (IgG) and neutralizing antibody activity in the two case patients. Case 1 had high anti-spike IgG detected on day 3 of the illness, with low neutralizing antibody activity. The neutralizing antibody activity started to increase on day 5 of the illness. In Case 2 both the anti-spike IgG and the neutralizing antibody activity remained low from days 4–11 of illness, and the anti-spike IgG gradually increased from day 9. In Case 1, the fever broke within 4 days of onset, coinciding with the rise in neutralizing antibodies, whereas the fever took 7 days to resolve in Case 2. SARS-CoV-2 infection can occur even in vaccinated individuals, but vaccination may contribute to milder clinical symptoms because neutralizing antibodies are induced earlier in vaccinated individuals than in unvaccinated individuals.     

Rates of Severe Outcomes After Bamlanivimab-Etesevimab and Casirivimab-Imdevimab Treatment of High-Risk Patients With Mild to Moderate Coronavirus Disease 2019

Bamlanivimab-etesevimab and casirivimab-imdevimab are authorized by the US Food and Drug Administration for emergency treatment of mild to moderate coronavirus disease 2019 (COVID-19) in high-risk persons. There has been no study comparing their clinical efficacy. In this retrospective study of 681 patients with mild to moderate COVID-19 during a period dominated by severe acute respiratory syndrome coronavirus 2 wild-type and alpha variants, 25 patients (3.7%) had progression to a severe outcome requiring hospitalization and oxygen supplementation within 30 days after monoclonal antibody infusion. Severe outcome was significantly higher among the 181 patients who were treated with casirivimab-imdevimab when compared with the 500 patients who received bamlanivimab-etesevimab (21 [6.6%] vs 13 [2.6%]; P=.01). Patients treated with casirivimab-imdevimab had higher odds of severe outcomes compared with those who received bamlanivimab-etesevimab (odds ratio, 2.67; 95% CI, 1.17 to 6.06). The demographic and clinical characteristics, and the time to monoclonal antibody infusion, of the 2 treatment cohorts were not significantly different. The reason behind this significant difference in the clinical outcomes is unclear, but our observations emphasize potential efficacy differences among antispike monoclonal antibodies against COVID-19. Further clinical studies using larger cohorts of patients are needed to confirm or refute these observations.     

Year 3 of COVID-19: Harsh Truths,Brutal Realities,and Glimmers of Hope

Severe acute respiratory syndrome coronavirus 2, the virus causing coronavirus disease 2019 (COVID-19), has now killed 1 of every 303 Americans. Whereas 4 vaccines are approved in the United States and masks are widely available, too few are fully immunized and most of the population has stopped wearing protective masks. The ongoing consequences of this include continued excess morbidity and mortality and the generation of immune-evading variants and subvariants, which in toto are injurious and ultimately self-defeating. Herein we briefly update and review COVID-19 vaccines, waning immunity, and new variants.     

Viral Endothelial Dysfunction: A Unifying Mechanism for COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible virus with significant global impact, morbidity, and mortality. The SARS-CoV-2 virus may result in widespread organ manifestations including acute respiratory distress syndrome, acute renal failure, thromboembolism, and myocarditis. Virus-induced endothelial injury may cause endothelial activation, increased permeability, inflammation, and immune response and cytokine storm. Endothelial dysfunction is a systemic disorder that is a precursor of atherosclerotic vascular disease that is associated with cardiovascular risk factors and is highly prevalent in patients with atherosclerotic cardiovascular and peripheral disease. Several studies have associated various viral infections including SARS-CoV-2 infection with inflammation, endothelial dysfunction, and subsequent innate immune response and cytokine storm. Noninvasive monitoring of endothelial function and identification of high-risk patients who may require specific therapies may have the potential to improve morbidity and mortality associated with subsequent inflammation, cytokine storm, and multiorgan involvement.     

Factors affecting the sensitivity of quantitative severe acute respiratory syndrome coronavirus 2 antigen test

IntroductionThe accuracy of nucleic acid amplification tests (NAATs) is affected by various factors; however, studies examining the factors affecting the accuracy of quantitative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen test (QAT) are limited.MethodsA total of 347 nasopharyngeal samples were collected from patients with coronavirus disease 2019 (COVID-19), and the date of onset was obtained from the electronic medical records. The SARS-CoV-2 antigen level was measured using Lumipulse Presto SARS-CoV-2 Ag (Presto), while NAAT was performed using the Ampdirect 2019-nCoV Detection Kit.ResultsPresto had a sensitivity rate of 95.1% (95% confidence interval: 92.8–97.4) in detecting the SARS-CoV-2 antigen in 347 samples. The number of days from symptom onset to sample collection was negatively correlated with the amount of antigen (r = −0.515) and sensitivity of Presto (r = −0.711). The patients’ age was lower in the Presto-negative samples (median age, 39 years) compared with that in the Presto-positive samples (median age, 53 years; p < 0.01). A significant positive correlation was observed between age (excluding teenagers) and Presto sensitivity (r = 0.764). Meanwhile, no association was found between the mutant strain, sex, and Presto results.ConclusionPresto is useful for the accurate diagnosis of COVID-19 owing to its high sensitivity when the number of days from symptom onset to sample collection is within 12 days. Furthermore, age may affect the results of Presto, and this tool has a relatively low sensitivity in younger patients.