Association between COVID-19 mRNA vaccination and COVID-19 illness and severity during Omicron BA.4 and BA.5 sublineage periods (preprint)

ABSTRACT Importance: Recent sublineages of the SARS-CoV-2 Omicron variant, including BA.4 and BA.5, may be associated with greater immune evasion and less protection against COVID-19 following vaccination. Objective: To evaluate the association between COVID-19 mRNA vaccination with 2, 3, or 4 doses among immunocompetent adults and the risk of medically attended COVID-19 illness during a period of BA.4/BA.5 predominant circulation; to evaluate the relative severity of COVID-19 in hospitalized cases across Omicron BA.1, BA.2/BA.2.12.1, and BA.4/BA.5 sublineage periods. Setting, Design and Participants: Test-negative study of adults with COVID-19-like illness (CLI) and molecular testing for SARS-CoV-2 conducted in 10 states from December 16, 2021, to August 20, 2022. Exposure: mRNA COVID-19 vaccination. Main Outcomes and Measures: Emergency department/urgent care encounters, hospitalizations, and admission to the intensive care unit (ICU) or in-hospital death. The adjusted odds ratio (OR) for the association between prior vaccination and medically attended COVID-19 was used to estimate VE, stratified by care setting and vaccine doses (2, 3, or 4 doses vs 0 doses as reference group). Among hospitalized case-patients, demographic and clinical characteristics and in-hospital outcomes including ICU admission and death were compared across sublineage periods. Results: Between June 19 - August 20, 2022, 82,229 ED/UC and 21,007 hospital encounters were included for the BA.4/BA.5 vaccine effectiveness analysis. Among adults hospitalized with CLI, the adjusted odds ratio (OR) was 0.75 (95% CI: 0.68-0.83) for receipt of 2 vaccine doses at [≥]150 days after receipt, 0.32 (95% CI: 0.20-0.50) for a third dose 7-119 days after receipt, and 0.64 (95% CI: 0.58-0.71) for a third dose [≥]120 days (median 235 days) after receipt for cases vs controls. For COVID-19-associated hospitalization, among patients ages [≥]65 years 7-59 and [≥]60 days (median 88 days) after a fourth dose, ORs were 0.34 (95% CI: 0.25-0.47) and 0.43 (95% CI: 0.34-0.56), respectively. Among hospitalized cases, ICU admission and/or in-hospital death occurred in 21.4% during the BA.1 vs 14.7% during the BA.4/BA.5 period (standardized mean difference: 0.17). Conclusion: VE against medically attended COVID-19 illness decreased over time since last dose; receipt of one or two booster doses increased effectiveness over a primary series alone.

Multiple pathways for SARS-CoV-2 resistance to nirmatrelvir (preprint)

Nirmatrelvir, an oral antiviral targeting the 3CL protease of SARS-CoV-2, has been demonstrated to be clinically useful in reducing hospitalization or death due to COVID-191,2. However, as SARS-CoV-2 has evolved to become resistant to other therapeutic modalities3-9, there is a concern that the same could occur for nirmatrelvir. Here, we have examined this possibility by in vitro passaging of SARS-CoV-2 in increasing concentrations of nirmatrelvir using two independent approaches, including one on a large scale in 480 wells. Indeed, highly resistant viruses emerged from both, and their sequences revealed a multitude of 3CL protease mutations. In the experiment done at scale, 53 independent viral lineages were selected with mutations observed at 23 different residues of the enzyme. Yet, several common mutational pathways to nirmatrelvir resistance were preferred, with a majority of the viruses descending from T21I, P252L, or T304I as precursor mutations. Construction and analysis of 13 recombinant SARS-CoV-2 clones, each containing a unique mutation or a combination of mutations showed that the above precursor mutations only mediated low-level resistance, whereas greater resistance required accumulation of additional mutations. E166V mutation conferred the strongest resistance (~300-fold), but this mutation resulted in a loss of viral replicative fitness that was restored by compensatory changes such as L50F and T21I. Structural explanations are discussed for some of the mutations that are proximal to the drug-binding site, as well as cross-resistance or lack thereof to ensitrelvir, another clinically important 3CL protease inhibitor. Our findings indicate that SARS-CoV-2 resistance to nirmatrelvir does readily arise via multiple pathways in vitro, and the specific mutations observed herein form a strong foundation from which to study the mechanism of resistance in detail and to shed light on the design of next generation protease inhibitors.

Partial ORF1ab Gene Target Failure with Omicron BA.2.12.1 (preprint)

Mutations in the viral genome of SARS-CoV-2 can impact the performance of molecular diagnostic assays. In some cases, such as S gene target failure, the impact can serve as a unique indicator of a particular SARS-CoV-2 variant and provide a method for rapid detection. Here we describe partial ORF1ab gene target failure (pOGTF) on the cobas(R) SARS-CoV-2 assays, defined by a [≥]2 thermocycles delay in detection of the ORF1ab gene compared to the E gene. We demonstrate that pOGTF is 97% sensitive and 99% specific for SARS-CoV-2 lineage BA.2.12.1, an emerging variant in the United States with spike L452Q and S704L mutations that may impact transmission, infectivity, and/or immune evasion. Increasing rates of pOGTF closely mirrored rates of BA.2.12.1 sequences uploaded to public databases, and, importantly increasing local rates of pOGTF also mirrored increasing overall test positivity. Use of pOGTF as a proxy for BA.2.12.1 provides faster tracking of the variant than whole-genome sequencing and can benefit laboratories without sequencing capabilities.

Reduction in risk of death among patients admitted with COVID-19 between first and second epidemic waves in New York City (preprint)

Many regions have experienced successive epidemic waves of COVID-19 since the emergence of SARS-CoV-2 with heterogeneous differences in mortality. Elucidating factors differentially associated with mortality between epidemic waves may inform clinical and public health strategies. We examined clinical and demographic data among patients admitted with COVID-19 during the first (March-June 2020) and second (December 2020-March 2021) epidemic waves at an academic medical center in New York City. Hospitalized patients (N=4631) had lower mortality during the second wave (14%) than the first (23%). Patients in the second wave had a lower 30-day mortality (Hazard Ratio (HR) 0.52, 95% CI 0.44, 0.61) than those in the first wave. The mortality decrease persisted after adjusting for confounders except for the volume of COVID-19 admissions (HR 0.88, 95% CI 0.70, 1.11), a measure of health system strain. Several demographic and clinical patient factors were associated with an increased risk of mortality independent of wave.

Molecular Pathophysiology of Cardiac Injury and Cardiac Microthrombi in Fatal COVID-19: Insights from Clinico-histopathologic and Single Nuclei RNA Sequencing Analyses (preprint)

Cardiac injury is strongly associated with critical COVID-19, yet its etiology remains debated. To elucidate the pathogenic mechanisms of COVID-19-associated cardiac injury, we conducted a single-center prospective cohort study of 69 COVID-19 decedents. Of six cardiac histopathologic features, microthrombi was the most commonly detected (n=48, 70%). We tested associations of cardiac microthrombi with biomarkers of inflammation, cardiac injury, and fibrinolysis and with in-hospital antiplatelet therapy, therapeutic anticoagulation, and corticosteroid treatment, while adjusting for multiple clinical factors, including COVID-19 therapies. Higher peak ESR and CRP during hospitalization were independently associated with higher odds of microthrombi. Using single nuclei RNA-sequence analysis, we discovered an enrichment of pro-thrombotic/anti-fibrinolytic, extracellular matrix remodeling, and immune-potentiating signaling amongst cardiac fibroblasts in microthrombi-positive COVID-19 hearts relative to microthrombi-negative COVID-19 and non-COVID-19 reference hearts. Our cumulative findings identify the specific transcriptomic changes in cardiac fibroblasts as salient features of COVID-19-associated cardiac microthrombi.

COVID-19 Neuropathology at Columbia University Irving Medical Center/New York Presbyterian Hospital (preprint)

Many patients with SARS-CoV-2 infection develop neurological signs and symptoms, though, to date, little evidence exists that primary infection of the brain is a significant contributing factor. We present the clinical, neuropathological, and molecular findings of 41 consecutive patients with SARS-CoV-2 infections who died and underwent autopsy in our medical center. The mean age was 74 years (38-97 years), 27 patients (66%) were male and 34 (83%) were of Hispanic/Latinx ethnicity. Twenty-four patients (59%) were admitted to the intensive care unit (ICU). Hospital-associated complications were common, including 8 (20%) with deep vein thrombosis/pulmonary embolism (DVT/PE), 7 (17%) patients with acute kidney injury requiring dialysis, and 10 (24%) with positive blood cultures during admission. Eight (20%) patients died within 24 hours of hospital admission, while 11 (27%) died more than 4 weeks after hospital admission. Neuropathological examination of 20-30 areas from each brain revealed hypoxic/ischemic changes in all brains, both global and focal; large and small infarcts, many of which appeared hemorrhagic; and microglial activation with microglial nodules accompanied by neuronophagia, most prominently in the brainstem. We observed sparse T lymphocyte accumulation in either perivascular regions or in the brain parenchyma. Many brains contained atherosclerosis of large arteries and arteriolosclerosis, though none had evidence of vasculitis. Eighteen (44%) contained pathologies of neurodegenerative diseases, not unexpected given the age range of our patients. We examined multiple fresh frozen and fixed tissues from 28 brains for the presence of viral RNA and protein, using quantitative reverse-transcriptase PCR (qRT- PCR), RNAscope, and immunocytochemistry with primers, probes, and antibodies directed against the spike and nucleocapsid regions. qRT-PCR revealed low to very low, but detectable, viral RNA levels in the majority of brains, although they were far lower than those in nasal epithelia. RNAscope and immunocytochemistry failed to detect viral RNA or protein in brains. Our findings indicate that the levels of detectable virus in COVID-19 brains are very low and do not correlate with the histopathological alterations. These findings suggest that microglial activation, microglial nodules and neuronophagia, observed in the majority of brains, do not result from direct viral infection of brain parenchyma, but rather likely from systemic inflammation, perhaps with synergistic contribution from hypoxia/ischemia. Further studies are needed to define whether these pathologies, if present in patients who survive COVID-19, might contribute to chronic neurological problems.

A Novel SARS-CoV-2 Variant of Concern, B.1.526, Identified in New York (preprint)

Recent months have seen surges of SARS-CoV-2 infection across the globe along with considerable viral evolution. Extensive mutations in the spike protein of variants B.1.1.7, B1.351, and P.1 have raised concerns that the efficacy of current vaccines and therapeutic monoclonal antibodies could be threatened. In vitro studies have shown that one mutation, E484K, plays a crucial role in the loss of neutralizing activity of some monoclonal antibodies as well as most convalescent and vaccinee sera against variant B.1.351. In fact, two vaccine trials have recently reported lower protective efficacy in South Africa, where B.1.351 is dominant. To survey for these novel variants in our patient population in New York City, PCR assays were designed to identify viruses with two signature mutations, E484K and N501Y. We observed a steady increase in the detection rate from late December to mid-February, with an alarming rise to 12.3% in the past two weeks. Whole genome sequencing further demonstrated that most of our E484K isolates (n=49/65) fell within a single lineage: NextStrain clade 20C or Pangolin lineage B.1.526. Patients with this novel variant came from diverse neighborhoods in the metropolitan area, and they were on average older and more frequently hospitalized. Phylogenetic analyses of sequences in the database further reveal that this B.1.526 variant is scattered in the Northeast of US, and its unique set of spike mutations may also pose an antigenic challenge for current interventions.

Antibody Testing Documents the Silent Spread of SARS-CoV-2in New York Prior to the First Reported Case (preprint)

We developed and validated serologic assays to determine SARS-CoV-2 seroprevalence in select patient populations in greater New York City area early during the epidemic. We tested “discarded” serum samples from February 24 to March 29 for antibodies against SARS-CoV-2 spike trimer and nucleocapsid protein. Using known durations for antibody development, incubation period, serial interval, and reproductive ratio for this pandemic, we determined that introduction of SARS-CoV-2 into New York likely occurred between January 23 and February 4, 2020. SARS-CoV-2 spread silently for 4–5 weeks before the first community acquired infection was reported. A novel coronavirus emerged in December 2019 in Wuhan, China1,2 and devasted Hubei Province in early 2020 before spreading to every province within China and nearly every country in the world3. This pathogen, now termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a global pandemic, with ~ 10 million cases and over 500,000 deaths reported through June 30, 20203. The first case of SARS-CoV-2 infection in the United States was identified on January 19, 2020 in a man who returned to the State of Washington from Wuhan4. In the ensuing months, the U.S. has become a hotspot of the pandemic, presently accounting for almost one third of the total caseload and over one fourth of the deaths3. The first confirmed case in New York was reported on March 1 in a traveler recently returned from Iran. The first community-acquired SARS-CoV-2 infection was diagnosed on March 3 in a 50-year-old male who lived in New Rochelle and worked in New York City (https://www1.nyc.gov/site/doh/covid/covid-19-data-archive.page.) In the ensuing 18 weeks, New York City has suffered a peak daily infection number of ~ 4,500 (Fig. 1a) and a cumulative caseload of ~ 400,000 to date. The time period when SARS-CoV-2 gained entry into this epicenter of the pandemic remains unclear.