New onset of hypomegakaryocytic thrombocytopenia with the potential for progression to aplastic anemia after BNT162b2 mRNA COVID-19 vaccination.

Vaccination with a coronavirus disease-2019 (COVID-19) vaccine is an effective public health measure for reducing the risk of infection and severe complications from COVID-19. However, serious hematological complications after COVID-19 vaccination have been reported. Here, we report a case of new-onset hypomegakaryocytic thrombocytopenia (HMT) with the potential for progression to aplastic anemia (AA) that developed in a 46-year-old man 4 days after the fourth mRNA COVID-19 vaccination. Platelet count rapidly decreased after vaccination and white blood cell count declined subsequently. Bone marrow examination immediately after disease onset showed severely hypocellular marrow (cellularity of almost 0%) in the absence of fibrosis, findings that were consistent with AA. Since the severity of pancytopenia did not meet the diagnostic criteria for AA, the patient was diagnosed with HMT that could progress to AA. Treatment with eltrombopag and cyclosporine was started immediately after diagnosis and cytopenia improved. Although it is difficult to determine whether the post-vaccination cytopenia was vaccine induced or accidental because the association was chronological, vaccination with an mRNA-based COVID-19 vaccine may be associated with development of HMT/AA. Therefore, physicians should be aware of this rare, but serious adverse event and promptly provide appropriate treatment.

A Multicenter Randomized Controlled Trial To Evaluate the Efficacy and Safety of Nelfinavir in Patients with Mild COVID-19.

Nelfinavir, an orally administered inhibitor of human immunodeficiency virus protease, inhibits the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro. We conducted a randomized controlled trial to evaluate the clinical efficacy and safety of nelfinavir in patients with SARS-CoV-2 infection. We included unvaccinated asymptomatic or mildly symptomatic adult patients who tested positive for SARS-CoV-2 infection within 3 days before enrollment. The patients were randomly assigned (1:1) to receive oral nelfinavir (750 mg; thrice daily for 14 days) combined with standard-of-care or standard-of-care alone. The primary endpoint was the time to viral clearance, confirmed using quantitative reverse-transcription PCR by assessors blinded to the assigned treatment. A total of 123 patients (63 in the nelfinavir group and 60 in the control group) were included. The median time to viral clearance was 8.0 (95% confidence interval [CI], 7.0 to 12.0) days in the nelfinavir group and 8.0 (95% CI, 7.0 to 10.0) days in the control group, with no significant difference between the treatment groups (hazard ratio, 0.815; 95% CI, 0.563 to 1.182; P = 0.1870). Adverse events were reported in 47 (74.6%) and 20 (33.3%) patients in the nelfinavir and control groups, respectively. The most common adverse event in the nelfinavir group was diarrhea (49.2%). Nelfinavir did not reduce the time to viral clearance in this setting. Our findings indicate that nelfinavir should not be recommended in asymptomatic or mildly symptomatic patients infected with SARS-CoV-2. The study is registered with the Japan Registry of Clinical Trials (jRCT2071200023). IMPORTANCE The anti-HIV drug nelfinavir suppresses the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro. However, its efficacy in patients with COVID-19 has not been studied. We conducted a multicenter, randomized controlled trial to evaluate the efficacy and safety of orally administered nelfinavir in patients with asymptomatic or mildly symptomatic COVID-19. Compared to standard-of-care alone, nelfinavir (750 mg, thrice daily) did not reduce the time to viral clearance, viral load, or the time to resolution of symptoms. More patients had adverse events in the nelfinavir group than in the control group (74.6% [47/63 patients] versus 33.3% [20/60 patients]). Our clinical study provides evidence that nelfinavir, despite its antiviral effects on SARS-CoV-2 in vitro, should not be recommended for the treatment of patients with COVID-19 having no or mild symptoms.

Anti-CD20 antibodies and bendamustine attenuate humoral immunity to COVID-19 vaccination in patients with B-cell non-Hodgkin lymphoma.

Serologic responses of COVID-19 vaccine are impaired in patients with B-cell lymphoma, especially those who had recently been treated with anti-CD20 monoclonal antibodies. However, it is still unclear whether those patients develop an immune response following vaccination. We investigated the efficacy of vaccination against SARS-CoV-2 in 171 patients with B-cell non-Hodgkin lymphoma (B-NHL) who received two doses of an mRNA-based COVID-19 vaccine and we compared the efficacy of vaccination to that in 166 healthy controls. Antibody titers were measured 3 months after administration of the second vaccine dose. Patients with B-NHL showed a significantly lower seroconversion rate and a lower median antibody titer than those in healthy controls. The antibody titers showed correlations with the period from the last anti-CD20 antibody treatment to vaccination, the period from the last bendamustine treatment to vaccination and serum IgM level. The serologic response rates and median antibody titers were significantly different between diffuse large B-cell lymphoma (DLBCL) patients in whom anti-CD20 antibody treatment was completed within 9 months before vaccination and follicular lymphoma (FL) patients in whom anti-CD20 antibody treatment was completed within 15 months before vaccination. Moreover, the serologic response rates and median antibody titers were significantly different among FL patients in whom bendamustine treatment was completed within 33 months before vaccination. We demonstrated that B-NHL patients who were recently treated with anti-CD20 antibodies and bendamustine had a diminished humoral response to COVID-19 vaccination. UMIN 000,045,267.

Humoral response to mRNA-based COVID-19 vaccine and booster effect of a third dose in patients with mature T cell and NK-cell neoplasms.

Patients with lymphoid malignancies have impaired humoral immunity caused by the disease itself and its treatment, placing them at risk for severe coronavirus disease-19 (COVID-19) and reduced response to vaccination. However, data for COVID-19 vaccine responses in patients with mature T cell and NK-cell neoplasms are very limited. In this study of 19 patients with mature T/NK-cell neoplasms, anti-severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) spike antibodies were measured at 3 months, 6 months, and 9 months after the second mRNA-based vaccination. At the time of the second and third vaccinations, 31.6% and 15.4% of the patients were receiving active treatment. All patients received the primary vaccine dose and the third vaccination rate was 68.4%. In patients with mature T/NK-cell neoplasms, both seroconversion rate (p < 0.01) and antibody titers (p < 0.01) after the second vaccination were significantly lower than those in healthy controls (HC). In individuals who received the booster dose, patients had significantly lower antibody titers than those in HC (p < 0.01); however, the seroconversion rate in patients was 100%, which was the same as that in HC. The booster vaccine resulted in a significant increase of antibodies in elderly patients who had shown a response that was inferior to that in younger patients after two doses of vaccination. Since higher antibody titers and higher seroconversion rate reduced the incidence of infection and mortality, vaccination more than three times may have the advantage for patients with mature T/NK-cell neoplasms, especially in elderly patients. Clinical trial registration number: UMIN 000,045,267 (August 26th, 2021), 000,048,764 (August 26th, 2022).

Humoral response to mRNA-based COVID-19 vaccine in patients with immune thrombocytopenia.

Data for COVID-19 vaccine response in patients with immune thrombocytopenia (ITP) are very limited. In a study of 28 patients with ITP, anti-severe acute respiratory syndrome coronavirus 2 spike antibody titres were measured after vaccination. The seroconversion rate for ITP patients was 91.3%, comparable to that in healthy controls (HCs). However, the antibody titre in ITP patients was significantly lower than that in HCs and declined with ageing. Furthermore, the antibody titre in ITP patients who received a minimum prednisolone dose of at least 5 mg/day at any time-point at or after initial vaccination was lower than that in other patients.

Multicenter, single-blind, randomized controlled study of the efficacy and safety of favipiravir and nafamostat mesilate in patients with COVID-19 pneumonia.

OBJECTIVES: To evaluate the efficacy and safety of nafamostat combined with favipiravir for the treatment of COVID-19. METHODS: We conducted a multicenter, randomized, single-blind, placebo-controlled, parallel assignment study in hospitalized patients with mild-to-moderate COVID-19 pneumonia. Patients were randomly assigned to receive favipiravir alone (n = 24) or nafamostat with favipiravir (n = 21). The outcomes included changes in the World Health Organization clinical progression scale score, time to improvement in body temperature, and improvement in oxygen saturation (SpO2). RESULTS: There was no significant difference in the changes in the clinical progression scale between nafamostat with favipiravir and favipiravir alone groups (median, -0.444 vs -0.150, respectively; least-squares mean difference, -0.294; P = 0.364). The time to improvement in body temperature was significantly shorter in the combination group (5.0 days; 95% confidence interval, 4.0-7.0) than in the favipiravir group (9.0 days; 95% confidence interval, 7.0-18.0; P =0.009). The changes in SpO2 were greater in the combination group than in the favipiravir group (0.526% vs -1.304%, respectively; least-squares mean difference, 1.831; P = 0.022). No serious adverse events or deaths were reported, but phlebitis occurred in 57.1% of the patients in the combination group. CONCLUSION: Although our study showed no differences in clinical progression, earlier defervescence, and recovery of SpO2 were observed in the combination group.

Casirivimab/Imdevimab for Active COVID-19 Pneumonia Which Persisted for Nine Months in a Patient with Follicular Lymphoma during Anti-CD20 Therapy.

Immunocompromised patients are more likely to develop severe COVID-19, and exhibit high mortality. It is also hypothesized that chronic infection in these patients can be a risk factor for developing new variants. We describe a patient with prolonged active infection of COVID-19 who became infected during treatment with an anti-CD20 antibody (obinutuzumab) for follicular lymphoma. This patient had persistent RT-PCR positivity and live virus isolation for nine months despite treatment with remdesivir and other potential antiviral therapies. The computed tomography image of the chest showed that the viral pneumonia repeatedly appeared and disappeared in different lobes, as if a new infection had occurred continuously. The patient's SARS-CoV-2 antibody titer was negative throughout the illness, even after two doses of the BNT162b2 mRNA vaccine were administered in the seventh month of infection. A combination of monoclonal antibody therapy against COVID-19 (casirivimab and imdevimab) and antivirals resulted in negative RT-PCR results, and the virus was no longer isolated. The patient was clinically cured. During the 9-month active infection period, no fixed mutations in the spike (S) protein were detected, and the in vitro susceptibility to remdesivir was retained. Therapeutic administration of anti-SARS-CoV-2 monoclonal antibodies is essential in immunocompromised patients. Therefore, measures to prevent resistance against these key drugs are urgently needed.

Favorable Outcome Following Sotrovimab Monoclonal Antibody in a Patient with Prolonged SARS-CoV-2 Omicron Infection with HIV/AIDS.

Persistent viral shedding or prolonged coronavirus disease 2019 (COVID-19) symptom is one of unresolved problem in immunocompromised individuals. We herein report an HIV/AIDS patient with Pneumocystis jirovecii pneumonia and prolonged COVID-19, possibly due to immune reconstitution inflammatory syndrome. His viral shedding and COVID-19 symptoms persisted for 39 days but were promptly resolved following sotrovimab monoclonal antibody therapy. This case suggests that prolonged COVID-19 and persistent viral shedding due to severe cellular immunodeficiency can occur in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) omicron infection and that sotrovimab is effective in the treatment of prolonged COVID-19 caused by omicron/BA.1.

Characterization and antiviral susceptibility of SARS-CoV-2 Omicron BA.2.

The recent emergence of SARS-CoV-2 Omicron (B.1.1.529 lineage) variants possessing numerous mutations has raised concerns of decreased effectiveness of current vaccines, therapeutic monoclonal antibodies and antiviral drugs for COVID-19 against these variants1,2. The original Omicron lineage, BA.1, prevailed in many countries, but more recently, BA.2 has become dominant in at least 68 countries3. Here we evaluated the replicative ability and pathogenicity of authentic infectious BA.2 isolates in immunocompetent and human ACE2-expressing mice and hamsters. In contrast to recent data with chimeric, recombinant SARS-CoV-2 strains expressing the spike proteins of BA.1 and BA.2 on an ancestral WK-521 backbone4, we observed similar infectivity and pathogenicity in mice and hamsters for BA.2 and BA.1, and less pathogenicity compared with early SARS-CoV-2 strains. We also observed a marked and significant reduction in the neutralizing activity of plasma from individuals who had recovered from COVID-19 and vaccine recipients against BA.2 compared to ancestral and Delta variant strains. In addition, we found that some therapeutic monoclonal antibodies (REGN10987 plus REGN10933, COV2-2196 plus COV2-2130, and S309) and antiviral drugs (molnupiravir, nirmatrelvir and S-217622) can restrict viral infection in the respiratory organs of BA.2-infected hamsters. These findings suggest that the replication and pathogenicity of BA.2 is similar to that of BA.1 in rodents and that several therapeutic monoclonal antibodies and antiviral compounds are effective against Omicron BA.2 variants.

Characterization of the SARS-CoV-2 B.1.621 (Mu) variant.

The SARS-CoV-2 B.1.621 (Mu) variant emerged in January 2021 and was categorized as a variant of interest by the World Health Organization in August 2021. This designation prompted us to study the sensitivity of this variant to antibody neutralization. In a live virus neutralization assay with serum samples from individuals vaccinated with the Pfizer/BioNTech or Moderna mRNA vaccines, we measured neutralization antibody titers against B.1.621, an early isolate (spike 614D), and a variant of concern (B.1.351, Beta variant). We observed reduced neutralizing antibody titers against the B.1.621 variant (3.4- to 7-fold reduction, depending on the serum sample and time after the second vaccination) compared to the early isolate and a similar reduction when compared to B.1.351. Likewise, convalescent serum from hamsters previously infected with an early isolate neutralized B.1.621 to a lower degree. Despite this antibody titer reduction, hamsters could not be efficiently rechallenged with the B.1.621 variant, suggesting that the immune response to the first infection is adequate to provide protection against a subsequent infection with the B.1.621 variant.

Anti-spike protein antibody titer at the time of breakthrough infection of SARS-CoV-2 omicron.

By December 2021, about 80% of people over the age of 12 had been vaccinated in Japan, and almost all people were vaccinated with the mRNA vaccine. We investigated here the anti-spike protein antibody titer at the time of breakthrough infection of SARS-CoV-2 omicron. A total of 32 SARS-CoV2 omicron breakthrough infection was included in the study. The median antibody titer at breakthrough infection was 776 AU/mL overall, of which the median antibody titer of BNT162b2 vaccinated was 633 AU/mL and that of mRNA-1273 vaccinated was 9416 AU/mL. This result suggests that low levels of antibody titers 6 months after vaccination do not provide sufficient antibodies to prevent the omicron variant breakthrough infection, which may occur with a higher anti-spike antibody titer after vaccination with mRNA-1273. However, antibody titers in some patients were comparable to those immediately after the second vaccination with either mRNA vaccine.

Association between pre-admission anticoagulation and in-hospital death, venous thromboembolism, and major bleeding among hospitalized COVID-19 patients in Japan.

PURPOSE: The coagulation activation leads to thrombotic complications such as venous thromboembolism (VTE) in patients with coronavirus disease-2019 (COVID-19). Prophylactic anticoagulation therapy has been recommended for hospitalized COVID-19 patients in clinical guidelines. This retrospective cohort study aimed to examine the association between pre-admission anticoagulation treatment and three outcomes: in-hospital death, VTE, and major bleeding among hospitalized COVID-19 patients in Japan. METHODS: Using a large-scale claims database built by the Medical Data Vision Co. in Japan, we identified patients hospitalized for COVID-19 who had outpatient prescription data at least once within 3 months before being hospitalized. Exposure was set as pre-admission anticoagulation treatment (direct oral anticoagulant or vitamin K antagonist), and outcomes were in-hospital death, VTE, and major bleeding. We conducted multivariable logistic regression analyses, adjusting for a single summarized score (a propensity score of receiving pre-admission anticoagulation) for VTE and major bleeding, due to the small number of outcomes. RESULTS: Among the 2612 analytic patients, 179 (6.9%) had pre-admission anticoagulation. Crude incidence proportions were 13.4% versus 8.5% for in-hospital death, 0.56% versus 0.58% for VTE, and 2.2% versus 1.1% for major bleeding among patients with and without pre-admission anticoagulation, respectively. Adjusted odds ratios (95% confidence intervals) were 1.25 (0.75-2.08) for in-hospital death, 0.21 (0.02-1.97) for VTE, and 2.63 (0.80-8.65) for major bleeding. Several sensitivity analyses did not change the results. CONCLUSIONS: We found no evidence that pre-admission anticoagulation treatment was associated with in-hospital death. However, a larger sample size may be needed to conclude its effect on VTE and major bleeding.

Correlation Analysis between Gut Microbiota Alterations and the Cytokine Response in Patients with Coronavirus Disease during Hospitalization.

The role of the intestinal microbiota in coronavirus disease 2019 (COVID-19) is being elucidated. Here, we analyzed the temporal changes in microbiota composition and the correlation between inflammation biomarkers/cytokines and microbiota in hospitalized COVID-19 patients. We obtained stool specimens, blood samples, and patient records from 22 hospitalized COVID-19 patients and performed 16S rRNA metagenomic analysis of stool samples over the course of disease onset compared to 40 healthy individual stool samples. We analyzed the correlation between the changes in the gut microbiota and plasma proinflammatory cytokine levels. Immediately after admission, differences in the gut microbiota were observed between COVID-19 patients and healthy subjects, mainly including enrichment of the classes Bacilli and Coriobacteriia and decrease in abundance of the class Clostridia. The bacterial profile continued to change throughout the hospitalization, with a decrease in short-chain fatty acid-producing bacteria including Faecalibacterium and an increase in the facultatively anaerobic bacteria Escherichia-Shigella. A consistent increase in Eggerthella belonging to the class Coriobacteriia was observed. The abundance of the class Clostridia was inversely correlated with interferon-γ level and that of the phylum Actinobacteria, which was enriched in COVID-19, and was positively correlated with gp130/sIL-6Rb levels. Dysbiosis was continued even after 21 days from onset. The intestines tended to be an aerobic environment in hospitalized COVID-19 patients. Because the composition of the gut microbiota correlates with the levels of proinflammatory cytokines, this finding emphasizes the need to understand how pathology is related to the temporal changes in the specific gut microbiota observed in COVID-19 patients. IMPORTANCE There is growing evidence that the commensal microbiota of the gastrointestinal and respiratory tracts regulates local and systemic inflammation (gut-lung axis). COVID-19 is primarily a respiratory disease, but the involvement of microbiota changes in the pathogenesis of this disease remains unclear. The composition of the gut microbiota of patients with COVID-19 changed over time during hospitalization, and the intestines tended to be an aerobic environment in hospitalized COVID-19 patients. These changes in gut microbiota may induce increased intestinal permeability, called leaky gut, allowing bacteria and toxins to enter the circulatory system and further aggravate the systemic inflammatory response. Since gut microbiota composition correlates with levels of proinflammatory cytokines, this finding highlights the need to understand how pathology relates to the gut environment, including the temporal changes in specific gut microbiota observed in COVID-19 patients.

Humoral response to mRNA-based COVID-19 vaccine in patients with myeloid malignancies.

Data on the response to the COVID-19 vaccine in patients with myeloid malignancy, who are at severe risk in case of infection, have not emerged. In a study of 69 patients with myeloid malignancies, including 46 patients with acute myeloid leukaemia (AML) and 23 patients with myelodysplastic syndrome (MDS), anti-spike SARS-CoV-2 antibody titres were measured 3 months after the second mRNA-based vaccination. Seroconversion rates for AML and MDS were 94.7% and 100% respectively, with no significant difference from healthy controls (HCs). Patients with MDS showed a significantly lower antibody titre than that in HCs or AML patients. In AML patients, the antibody titres were comparable to those in HCs when treatment was completed, but lower in patients under maintenance therapy. The response to COVID-19 vaccine appears to be related to disease and treatment status. Patients with myeloid malignancies may be more responsive to vaccines than patients with lymphoid malignancies.