Efficacy of preexposure prophylaxis with monoclonal-antibody tixagevimab-cilgavimab against emerging SARS-CoV-2 resistant variants in patients with chronic lymphocytic leukemia.

Introduction Pre exposure prophylaxis with monoclonal antibodies (mAbs) were developed in addition to COVID19 vaccine for immunocompromised and those with insufficient immune response, among them patients with CLL. Omicron variant and its sublineages evolved mutations that escape mAbs neutralizing effect, yet the extent of which was not studied. Methods We evaluated anti-spike titters and neutralization activity of COVID-19 wild type (WT) , Delta , Omicron, BA2, BA4 and BA5 before and after tixagevimab-cilgavimab (TGM/CGM) dose of 150/150mg or 300/300mg in patients with CLL. Results 70 patients were tested 2 weeks before and 4 weeks after receiving TGM/CGM mAbs. After TGM/CGM anti-spike ab level increased 170 folds from 13.6 BAU/ml (IQR, 0.4-288) to 2328 BAU/ml (IQR, 1681-3500). Neutralization activity increased in all variants, and was 176 folds higher in WT and 55 folds higher in Delta compared to 10 folds higher in Omicron and its sublineages (BA2 x11, BA4 x4 , BA5 x18). Over follow-up period of 3 months, 20 patients (29%) with CLL acquired COVID-19 infection, all recovered uneventfully. In a multivariate analysis anti-spike antibody titer was found a significant predictor for post TGM/CGM COVID19 infection. Conclusion Efficacy of preexposure prophylaxis with TGM/CGM in patients with CLL is significantly reduced in era of Omicron and its sublineages BA2, BA4 and BA5.

Ep300 sequestration to functionally distinct glucocorticoid receptor binding loci underlie rapid gene activation and repression.

The rapid transcriptional response to the transcription factor, glucocorticoid receptor (GR), including gene activation or repression, is mediated by the spatial association of genes with multiple GR binding sites (GBSs) over large genomic distances. However, only a minority of the GBSs have independent GR-mediated activating capacity, and GBSs with independent repressive activity were rarely reported. To understand the positive and negative effects of GR we mapped the regulatory environment of its gene targets. We show that the chromatin interaction networks of GR-activated and repressed genes are spatially separated and vary in the features and configuration of their GBS and other non-GBS regulatory elements. The convergence of the KLF4 pathway in GR-activated domains and the STAT6 pathway in GR-repressed domains, impose opposite transcriptional effects to GR, independent of hormone application. Moreover, the ROR and Rev-erb transcription factors serve as positive and negative regulators, respectively, of GR-mediated gene activation. We found that the spatial crosstalk between GBSs and non-GBSs provides a physical platform for sequestering the Ep300 co-activator from non-GR regulatory loci in both GR-activated and -repressed gene compartments. While this allows rapid gene repression, Ep300 recruitment to GBSs is productive specifically in the activated compartments, thus providing the basis for gene induction.

Cocirculation of A(H3N2) and B/Victoria increased morbidity in hospitalized patients in the 2019-2020 A(H1N1)pdm09 predominant influenza season in Israel.

Community surveillance found the 2019-2020 A(H1N1)pdm09 predominant influenza season in Israel to be a high-intensity season with an early and steep morbidity peak. To further characterize disease severity in the 2019-2020 season, we analyzed a cohort of hospitalized patients with laboratory-confirmed influenza from this season (n = 636). Quantitative polymerase chain reaction was performed on clinical samples to detect the presence of influenza. Demographic, clinical, and laboratory data were retrieved via electronic health records and MDClone. Electronic health records were accessed to obtain data on intensive care unit patients, missing data and for data verification purposes. Univariate analysis was performed to compare demographic, comorbidity, and clinical characteristics across the three influenza strains. The A(H1N1)pdm09 predominant 2019-2020 influenza season in Israel was characterized by an early and steep morbidity peak, vaccine delays and shortages, and with the A(H3N2) and B/Victoria strains disproportionately targeting children and young adults, most probably due to reduced immunity to these strains. A greater proportion of children <5 years infected with A(H3N2) and B/Victoria developed severe influenza compared with those infected with A(H1N1)pdm09. Our study emphasizes the vulnerability of infants and young children in the face of rapidly evolving influenza strains and underscores the importance of influenza prevention measures in this population.

BNT162b2-vaccine-induced neutralization responses are immune correlates of clinical protection against SARS-CoV-2 in heart transplant recipients.

BACKGROUND: Defining immune correlates of protection against COVID-19 is pivotal for optimizing the use of COVID-19 vaccines, predicting the impact of novel variants on clinical outcomes, and advancing the development of immunotherapies and next-generation vaccines. We aimed to identify vaccine-induced immune correlates of protection against COVID-19-related hospitalizations in a highly vaccinated heart transplant (HT) cohort. METHODS: In a case-control study of HT recipients vaccinated with the BNT162b2 vaccine, patients were prospectively assessed for vaccine-induced neutralization of the wild-type virus, and the Delta and Omicron BA.1, BA.2, BA.4, and BA.5 variants. Comparative analyses with controls were conducted to identify correlates of protection against COVID-19 hospitalization. ROC analyses were performed. Primary outcomes were COVID-19 hospitalizations and severity of SARS-CoV-2 breakthrough infection. RESULTS: The study cohort comprised 59 HT recipients aged 58 (49,65) years with breakthrough infections after three or four monovalent BNT162b2 doses; 41 (69.5%) were men. Thirty-six (61%) patients with COVID-19 were hospitalized; most cases were non-severe (58, 98%). For hospitalized (vs. non-hospitalized) COVID-19 patients, vaccine-induced neutralization titers were significantly lower against all SARS-CoV-2 variants (p < .005). Vaccine-induced neutralization of the wild-type virus and delta and omicron BA.1, BA.2, BA.4, and BA.5 variants was associated with a reduced risk for COVID-19-related hospitalization. The optimal neutralization titer thresholds that were predictive of COVID-19 hospitalizations were 96 (wild-type), 48 (delta), 12 (BA.1), 96 (BA.2), 96 (BA.4), and 48 (BA.5). CONCLUSIONS: BNT162b2-vaccine-induced neutralization responses are immune correlates of protection and confer clinical protection against COVID-19 hospitalizations.

Early Immunogenicity and Safety of the Third Dose of BNT162b2 Messenger RNA Coronavirus Disease 2019 Vaccine Among Adults Older Than 60 Years: Real-World Experience.

BACKGROUND: Despite high vaccine coverage, an increase in breakthrough coronavirus disease 2019 (COVID-19) infections, prompted administration of a third BNT162b2 dose to people aged >60 years in Israel since July 2021. Here, we report real-world immunogenicity following third dose. METHODS: Overall, 208 healthcare workers aged >60 years were included. Paired pre- and post-second and/or third dose immunoglobulin G (IgG) and neutralizing antibody titers were compared. A subpopulation of low responders to the second dose was also tested for T-cell activation. For 25 paired serum samples, we tested neutralization of wild-type vs neutralization of Delta and Lambda variants, pre- and post-third dose. Active surveillance of vaccine adverse events was conducted through surveys. RESULTS: A pronounced immune response was observed following the third dose, including a 33-fold and 51-fold increase in IgG and neutralizing antibody, respectively. The neutralizing antibody levels post-third dose were 9.34 times higher than post-second dose (geometric mean titer, 2598 [95% confidence interval {CI}, 2085-3237] vs 207 [95% CI, 126-339]). Nine previously low responders had a significant antibody increase post-third dose, and 7 of 9 showed increase in T-cell activation. Additionally, sera obtained post-third dose highly and comparably neutralized the wild-type and Delta and Lambda variants. Of 1056 responders to the adverse-event survey, none had serious events. CONCLUSIONS: We demonstrate a rapid and broad immune response to the third BNT162b2 dose in individuals >60 years of age.

Omicron BA.2.75 variant is efficiently neutralised following BA.1 and BA.5 breakthrough infection in vaccinated individuals, Israel, June to September 2022.

We evaluated neutralising antibody titres against wild type (WT) SARS-CoV-2 and four Omicron variants (BA.1, BA.2, BA.5 and BA.2.75) in fully vaccinated (three doses of Comirnaty vaccine) healthcare workers (HCW) in Israel who had breakthrough BA.1/BA5 infections. Omicron breakthrough infections in vaccinated individuals resulted in increased neutralising antibodies against the WT and Omicron variants compared with vaccinated uninfected HCW. HCW who recovered from BA.1 or BA.5 infections showed similar neutralising antibodies levels against BA.2.75.

The impact of SARS-CoV-2 on respiratory syndromic and sentinel surveillance in Israel, 2020: a new perspective on established systems.

BackgroundThe COVID-19 pandemic presented new challenges for the existing respiratory surveillance systems, and adaptations were implemented. Systematic assessment of the syndromic and sentinel surveillance platforms during the pandemic is essential for understanding the value of each platform in the context of an emerging pathogen with rapid global spread.AimWe aimed to evaluate systematically the performance of various respiratory syndromic surveillance platforms and the sentinel surveillance system in Israel from 1 January to 31 December 2020.MethodsWe compared the 2020 syndromic surveillance trends to those of the previous 3 years, using Poisson regression adjusted for overdispersion. To assess the performance of the sentinel clinic system as compared with the national SARS-CoV-2 repository, a cubic spline with 7 knots and 95% confidence intervals were applied to the sentinel network's weekly percentage of positive SARS-CoV-2 cases.ResultsSyndromic surveillance trends changed substantially during 2020, with a statistically significant reduction in the rates of visits to physicians and emergency departments to below previous years' levels. Morbidity patterns of the syndromic surveillance platforms were inconsistent with the progress of the pandemic, while the sentinel surveillance platform was found to reflect the national circulation of SARS-CoV-2 in the population.ConclusionOur findings reveal the robustness of the sentinel clinics platform for the surveillance of the main respiratory viruses during the pandemic and possibly beyond. The robustness of the sentinel clinics platform during 2020 supports its use in locations with insufficient resources for widespread testing of respiratory viruses.

COVID-19 vaccination and BA.1 breakthrough infection induce neutralising antibodies which are less efficient against BA.4 and BA.5 Omicron variants, Israel, March to June 2022.

This work evaluated neutralising antibody titres against wild type (WT) SARS-CoV-2 and four Omicron variants (BA.1, BA.2, BA.4 and BA.5) in healthcare workers who had breakthrough BA.1 infection. Omicron breakthrough infection in individuals vaccinated three or four times before infection resulted in increased neutralising antibodies against the WT virus. The fourth vaccine dose did not further improve the neutralising efficiency over the third dose against all Omicron variants, especially BA.4 and BA.5. An Omicron-specific vaccine may be indicated.

Sensitive Immunodetection of Severe Acute Respiratory Syndrome Coronavirus 2 Variants of Concern 501Y.V2 and 501Y.V1.

Emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants may influence the effectiveness of existing laboratory diagnostics. In the current study we determined whether the British (20I/501Y.V1) and South African (20H/501Y.V2) SARS-CoV-2 variants of concern are detected with an in-house S1-based antigen detection assay, analyzing spiked pools of quantitative reverse-transcription polymerase chain reaction-negative nasopharyngeal swab specimens. The assay, combining 4 monoclonal antibodies, allowed sensitive detection of both the wild type and the variants of concern, despite accumulation of several mutations in the variants' S1 region-results suggesting that this combination, targeting distinct epitopes, enables both specificity and the universality.

Neutralising capacity against Delta (B.1.617.2) and other variants of concern following Comirnaty (BNT162b2, BioNTech/Pfizer) vaccination in health care workers, Israel.

SARS-CoV-2 Delta (B.1.617.2) variant of concern (VOC) and other VOCs are spreading in Europe. Micro-neutralisation assays with sera obtained after Comirnaty (BNT162b2, BioNTech/Pfizer) vaccination in 36 healthcare workers (31 female) demonstrated significant fold change reduction in neutralising titres compared with the original virus: Gamma (P.1) 2.3, Beta (B.1.351) 10.4, Delta 2.1 and 2.6. The reduction of the Alpha (B.1.1.7) variant was not significant. Despite being lower, remaining neutralisation capacity conferred by Comirnaty against Delta and other VOCs is probably protective.

The SARS-CoV-2 Lambda variant and its neutralisation efficiency following vaccination with Comirnaty, Israel, April to June 2021.

The SARS-CoV-2 Lambda (Pango lineage designation C.37) variant of interest, initially identified in Peru, has spread to additional countries. First detected in Israel in April 2021 following importations from Argentina and several European countries, the Lambda variant infected 18 individuals belonging to two main transmission chains without further spread. Micro-neutralisation assays following Comirnaty (BNT162b2 mRNA, BioNTech-Pfizer) vaccination demonstrated a significant 1.6-fold reduction in neutralising titres compared with the wild type virus, suggesting increased susceptibility of vaccinated individuals to infection.

Sixth monovalent XBB.1.5 vaccine elicits robust immune response against emerging SARS-CoV-2 variants in heart transplant recipients.

Continued circulation of severe acute respiratory syndrome coronavirus 2 has driven the selection of variants with improved ability to escape preexisting vaccine-induced responses, posing a persistent threat to heart transplant recipients (HTRs). The immunogenicity and safety of the updated XBB.1.5-containing monovalent vaccines are unknown. We prospectively enrolled 52 HTRs who had previously received a 5-dose ancestral-derived monovalent and bivalent messenger RNA (mRNA) vaccination schedule to receive the monovalent XBB.1.5 vaccine. Immunogenicity was evaluated using live virus microneutralization assays. The XBB.1.5 monovalent vaccine elicited potent and diverse neutralizing responses and broadened the reactivity spectrum to encompass newer strains, with the highest increase in neutralization activity being more pronounced against XBB.1.5 (15.8-fold) and JN.1 (13.3-fold) than against BA.5 (6.7-fold) and wild-type (4-fold). Notably, XBB.1.5 and JN.1 were resistant to neutralization by prevaccination sera. There were no safety concerns. Our findings support the updating of coronavirus disease 2019 vaccines to match antigenically divergent variants and exclude ancestral spike-antigen to protect HTRs.

Fifth bivalent omicron BA.4/BA.5 vaccination neutralization of SARS-CoV-2 in heart transplant recipients.

In 2022, the antigenically divergent SARS-CoV-2 omicron variants (BA.1, BA.2, BA.4, BA.5) outcompeted previous variants and continued to cause substantial numbers of illnesses and deaths. We evaluated the safety and immunogenicity of the bivalent original/omicron BA.4/BA.5 Pfizer/BioNTech vaccine administered as a fifth dose to heart transplant recipients (HTxRs). We compared neutralization (using live virus assays) of SARS-CoV-2-infected cells in serum samples from HTxRs who had previously received 4 doses of the monovalent BNT162b2 vaccine with samples from HTxRs with breakthrough infection after 4 monovalent BNT162b2 doses. The fifth vaccination induced high neutralization efficiency against the wild-type virus and omicron BA.1, BA.2, BA.4, and BA.5 variants, with significantly higher neutralization efficiency being induced in HTxRs with breakthrough infection than in those without. Neutralizing titers in those with breakthrough infection were sustained above the level induced by the fifth dose in the uninfected. We conclude that the fifth bivalent vaccine is immunogenic, including to variants, with higher vaccine immunogenicity conferred by breakthrough infection. Nevertheless, the clinical protection conferred by the fifth dose is yet to be determined. The sustained neutralization responses in those with breakthrough infection support the notion of delaying booster in those with natural breakthrough infection.

Immunogenicity of Co-Administered Omicron BA.4/BA.5 Bivalent COVID-19 and Quadrivalent Seasonal Influenza Vaccines in Israel during the 2022-2023 Winter Season.

Vaccination against COVID-19 and influenza provides the best defense against morbidity and mortality. Administering both vaccines concurrently may increase vaccination rates and reduce the burden on the healthcare system. This study evaluated the immunogenicity of healthcare workers in Israel who were co-administered with the Omicron BA.4/BA.5 bivalent COVID-19 vaccine and the 2022-2023 quadrivalent influenza vaccine. SARS-CoV-2 neutralizing antibody titers were measured via microneutralization while influenza antibody titers were measured via hemagglutination inhibition. No immunogenic interference was observed by either vaccine when co-administered. Antibody titers against SARS-CoV-2 variants increased significantly in the cohort receiving the COVID-19 vaccine alone and in combination with the influenza vaccine. Antibody titers against the A/H1N1 influenza strain increased significantly in the cohort receiving the influenza vaccine alone and in combination with the COVID-19 vaccine. Antibody titers against B/Victoria increased significantly in the cohort that received both vaccines. This study has important public health implications for the 2023-2024 winter season, and supports co-administration of both vaccines as a viable immunization strategy.

Influenza vaccine compatibility among hospitalized patients during and after the COVID-19 pandemic.

Introduction: Following the significant decrease in SARS-CoV-2 cases worldwide, Israel, as well as other countries, have again been faced with a rise in seasonal influenza. This study compared circulating influenza A and B in hospitalized patients in Israel with the influenza strains in the vaccine following the 2021-2022 winter season which was dominated by the omicron variant. Methods: Nasopharyngeal samples of 16,325 patients were examined for the detection of influenza A(H1N1)pdm09, influenza A(H1N1)pdm09 and influenza B. Phylogenetic trees of hemagglutinin were then prepared using sanger sequencing. Vaccine immunogenicity was also performed using the hemagglutination inhibition test. Results: Of the 16,325 nasopharyngeal samples collected from hospitalized patients between September 2021 (Week 40) and April 2023 (Week 15), 7.5% were found to be positive for influenza. Phylogenetic analyses show that in the 2021-2022 winter season, the leading virus subtype was influenza A(H3N2), belonging to clade 3C.2a1b.2a.2. However, the following winter season was dominated by influenza A(H1N1)pdm09, which belongs to clade 6B.aA.5a.2. The circulating influenza A(H1N1)pdm09 strain showed a shift from the vaccine strain, while the co-circulating influenza A(H3N2) and influenza B strains were similar to those of the vaccine. Antigenic analysis coincided with the sequence analysis. Discussion: Influenza prevalence during 2022-2023 returned to typical levels as seen prior to the emergence of SARS-CoV-2, which may suggest a gradual viral adaptation to SARS-CoV-2 variants. Domination of influenza A(H1N1)pdm09 was observed uniquely in Israel compared to Europe and USA and phylogenetic and antigenic analysis showed lower recognition of the vaccine with the circulating influenza A(H1N1)pdm09 in Israel compared to the vaccine.

Reduced Neutralization Efficacy against Omicron Variant after Third Boost of BNT162b2 Vaccine among Liver Transplant Recipients.

The immune responses of liver transplant (LT) recipients after the third boost of the BNT162b2mRNA vaccine improved. This study evaluates the durability of the immune response of LT recipients after the third boost, its predictors, and the impact of emerging variants. The receptor-binding domain IgG was determined at median times of 22 (first test) and 133 days (second test) after the administration of the third boost. IgG antibody titers > 21.4 BAU/mL were defined as a positive response. The neutralization efficacies of the vaccine against the wild-type, Omicron, and Delta variants were compared in the first test. The 59 LT recipients were of a median age of 61 years (range 25−82); 53.5% were male. Following administration of the third dose, the positive immune response decreased from 81.4% to 76.3% between the first and second tests, respectively, (p < 0.0001). The multivariate analysis identified CNI monotherapy (p = 0.02) and hemoglobin > 12 g/dL (p = 0.02) as independent predictors of a maintained positive immune response 133 days after the third dose. The geometric mean titers of Omicron neutralization were significantly lower than the wild-type and Delta virus (21, 137, 128, respectively; p < 0.0001). The immune response after the third BNT162b2mRNA vaccine dose decreased significantly in LT recipients. Further studies are required to evaluate the efficacy of the fourth vaccine dose and the durability of the immune response.