Long-term outcomes of PGA-TMC absorbable synthetic scaffold in both clean and contaminated ventral hernia repairs

BACKGROUND

Biosynthetic meshes afford the cost advantages of being made from fully synthetic material, but are also biodegradable, making them a versatile option that can be used in both clean and contaminated cases. The aim of this study is to evaluate the safety profile and long-term outcomes of using GORE BIO-A (BIO-A) as an adjunct to abdominal wall reconstruction in all wound classes.

METHODS

A retrospective review identified patients undergoing abdominal hernia repair using BIO-A from October 2008 to June 2018. The primary outcome was hernia recurrence rate. Only patients with at least 6-month follow-up were included when looking at recurrence rates. Secondary outcomes included 30-day morbidity categorized according to CDC Surgical Site Infection Criteria, return to operating/procedure room (RTOR), 30-day readmission, length of stay (LOS), and mortality.

RESULTS

A total of 207 patients were identified, CDC Wound Classification breakdown was 127 (61.4%), 41 (19.8%), 14 (6.8%), and 25 (12.1%) for wound classes I, II, III, and IV, respectively. Median follow-up was 55.4 months (range 0.2-162.4). Overall recurrence rate was 17.4%. Contaminated cases experienced higher recurrence rates (28.8% versus 10.4%, p = 0.002) at a mean follow up of 46.9 and 60.8 months for contaminated and clean patients, respectively. Recurrent patients had higher BMI (32.4 versus 28.4 kg/m2, p = 0.0011), larger hernias (162.2 versus 106.7 cm2, p = 0.10), higher LOS (11.1 versus 5.6 days, p = 0.0051), and higher RTOR rates (16.7% versus 5.6%, p = 0.053). 51 (24.5%) patients experienced some morbidity, including 19 (9.2%) surgical site occurences, 7 (3.4%) superficial surgical site infections, 16 (7.7%) deep surgical site infections, and 1 (0.5%) organ space infection.

CONCLUSION

This study affirms the use of biosynthetic mesh as a cost-effective alternative in all wound classifications, yielding good outcomes, limited long-term complications, and low recurrence. rates.

Modeling the emergence of viral resistance for SARS-CoV-2 during treatment with an anti-spike monoclonal antibody

To mitigate the loss of lives during the COVID-19 pandemic, emergency use authorization was given to several anti-SARS-CoV-2 monoclonal antibody (mAb) therapies for the treatment of mild-to-moderate COVID-19 in patients with a high risk of progressing to severe disease. Monoclonal antibodies used to treat SARS-CoV-2 target the spike protein of the virus and block its ability to enter and infect target cells. Monoclonal antibody therapy can thus accelerate the decline in viral load and lower hospitalization rates among high-risk patients with variants susceptible to mAb therapy. However, viral resistance has been observed, in some cases leading to a transient viral rebound that can be as large as 3-4 orders of magnitude. As mAbs represent a proven treatment choice for SARS-CoV-2 and other viral infections, evaluation of treatment-emergent mAb resistance can help uncover underlying pathobiology of SARS-CoV-2 infection and may also help in the development of the next generation of mAb therapies. Although resistance can be expected, the large rebounds observed are much more difficult to explain. We hypothesize replenishment of target cells is necessary to generate the high transient viral rebound. Thus, we formulated two models with different mechanisms for target cell replenishment (homeostatic proliferation and return from an innate immune response antiviral state) and fit them to data from persons with SARS-CoV-2 treated with a mAb. We showed that both models can explain the emergence of resistant virus associated with high transient viral rebounds. We found that variations in the target cell supply rate and adaptive immunity parameters have a strong impact on the magnitude or observability of the viral rebound associated with the emergence of resistant virus. Both variations in target cell supply rate and adaptive immunity parameters may explain why only some individuals develop observable transient resistant viral rebound. Our study highlights the conditions that can lead to resistance and subsequent viral rebound in mAb treatments during acute infection.

Erratum to: Progress Note 2024: Curing HIV; Not in My Lifetime or Just Around the Corner?

[This corrects the article DOI: 10.20411/pai.v8i2.665.].

Maximizing mesh mileage: evaluating the long-term performance of a novel hybrid mesh for ventral hernia repair

PURPOSE

The objective of this study is to evaluate the safety and long-term outcomes of GORE Synecor™ in ventral hernia repair (VHR).

METHODS

This retrospective, single-center case review analyzed outcomes in patients who underwent VHR with Synecor from May 2016 to December 2022. Primary outcomes were hernia recurrence and mesh infection rates. Secondary outcomes were 30-day morbidity, 30-day mortality, 30-day readmission, re-operation, surgical-site infection (SSI) and occurrence (SSO) rates, and occurrences requiring intervention (SSOI).

RESULTS

278 patients were identified. Mean follow-up was 24.1 (0.2-87.1) months. Mean hernia defect size was 63.4 (± 77.2) cm2. Overall hernia recurrence and mesh infection rates were 5.0% and 1.4% respectively. No mesh infections required full explantation. We report the following overall rates: 13.3% 30-day morbidity, 4.7% 30-day readmission, 2.9% re-operation, 7.2% SSI, 6.1% SSO, and 2.9% SSOI. 30-day morbidity was significantly higher in non-clean (42.1% vs 11.2%, p < 0.01), onlay (OL) mesh (37.0% vs preperitoneal (PP) 16.4%, p = 0.05 vs retrorectus (RR) 15.0%, p < 0.05 vs intraperitoneal (IP) 5.2%, p < 0.001), and open cases (23.5% vs 3.1% laparoscopic vs 4.4% robotic, p < 0.01). SSI rates were significantly higher in non-clean (31.6% vs 5.4%, p < 0.001), OL mesh (29.6% vs RR 11.3%, p < 0.05 vs PP 5.5%, p < 0.01 vs IP 0.0%, p < 0.001), and open cases (15.2% vs 0% laparoscopic vs 0% robotic, p < 0.05).

CONCLUSION

Long-term performance of a novel hybrid mesh in VHR demonstrates a low recurrence rate and favorable safety profile in various defect sizes and mesh placement locations.

Progress Note 2024: Curing HIV; Not in My Lifetime or Just Around the Corner?

Once a death sentence, HIV is now considered a manageable chronic disease due to the development of antiretroviral therapy (ART) regimens with minimal toxicity and a high barrier for genetic resistance. While highly effective in arresting AIDS progression and rendering the virus untransmissible in people living with HIV (PLWH) with undetectable viremia (U=U) [1, 2]), ART alone is incapable of eradicating the "reservoir" of resting, latently infected CD4+ T cells from which virus recrudesces upon treatment cessation. As of 2022 estimates, there are 39 million PLWH, of whom 86% are aware of their status and 76% are receiving ART [3]. As of 2017, ART-treated PLWH exhibit near normalized life expectancies without adjustment for socioeconomic differences [4]. Furthermore, there is a global deceleration in the rate of new infections [3] driven by expanded access to pre-exposure prophylaxis (PrEP), HIV testing in vulnerable populations, and by ART treatment [5]. Therefore, despite outstanding issues pertaining to cost and access in developing countries, there is strong enthusiasm that aggressive testing, treatment, and effective viral suppression may be able to halt the ongoing HIV epidemic (ie, UNAIDS' 95-95-95 targets) [6-8]; especially as evidenced by recent encouraging observations in Sydney [9]. Despite these promising efforts to limit further viral transmission, for PLWH, a "cure" remains elusive; whether it be to completely eradicate the viral reservoir (ie, cure) or to induce long-term viral remission in the absence of ART (ie, control; Figure 1). In a previous salon hosted by Pathogens and Immunity in 2016 [10], some researchers were optimistic that a cure was a feasible, scalable goal, albeit with no clear consensus on the best route. So, how are these cure strategies panning out? In this commentary, 8 years later, we will provide a brief overview on recent advances and failures towards identifying determinants of viral persistence and developing a scalable cure for HIV. Based on these observations, and as in the earlier salon, we have asked several prominent HIV cure researchers for their perspectives.

Safety and Immune Responses Following Anti-PD-1 Monoclonal Antibody Infusions in Healthy Persons With Human Immunodeficiency Virus on Antiretroviral Therapy

Background

T cells in people with human immunodeficiency virus (HIV) demonstrate an exhausted phenotype, and HIV-specific CD4+ T cells expressing programmed cell death 1 (PD-1) are enriched for latent HIV, making antibody to PD-1 a potential strategy to target the latent reservoir.

Methods

This was a phase 1/2, randomized (4:1), double-blind, placebo-controlled study in adults with suppressed HIV on antiretroviral therapy with CD4+ counts ≥350 cells/μL who received 2 infusions of cemiplimab versus placebo. The primary outcome was safety, defined as any grade 3 or higher adverse event (AE) or any immune-related AE (irAE). Changes in HIV-1-specific polyfunctional CD4+ and CD8+ T-cell responses were evaluated.

Results

Five men were enrolled (median CD4+ count, 911 cells/μL; median age, 51 years); 2 received 1 dose of cemiplimab, 2 received 2 doses, and 1 received placebo. One participant had a probable irAE (thyroiditis, grade 2); another had a possible irAE (hepatitis, grade 3), both after a single low-dose (0.3 mg/kg) infusion. The Safety Monitoring Committee recommended no further enrollment or infusions. All 4 cemiplimab recipients were followed for 48 weeks. No other cemiplimab-related serious AEs, irAEs, or grade 3 or higher AEs occurred. One 2-dose recipient of cemiplimab had a 6.2-fold increase in polyfunctional, Gag-specific CD8+ T-cell frequency with supportive increases in plasma HIV RNA and decreases in total HIV DNA.

Conclusions

One of 4 participants exhibited increased HIV-1-specific T-cell responses and transiently increased HIV-1 expression following 2 cemiplimab infusions. The occurrence of irAEs after a single, low dose may limit translating the promising therapeutic results of cemiplimab for cancer to immunotherapeutic and latency reversal strategies for HIV. Clinical Trials Registration. NCT03787095.

Predictors of HIV rebound differ by timing of antiretroviral therapy initiation

BACKGROUNDIdentifying factors that predict the timing of HIV rebound after treatment interruption will be crucial for designing and evaluating interventions for HIV remission.METHODSWe performed a broad evaluation of viral and immune factors that predict viral rebound (AIDS Clinical Trials Group A5345). Participants initiated antiretroviral therapy (ART) during chronic (N = 33) or early (N = 12) HIV infection with ≥ 2 years of suppressive ART and restarted ART if they had 2 viral loads ≥ 1,000 copies/mL after treatment interruption.RESULTSCompared with chronic-treated participants, early-treated individuals had smaller and fewer transcriptionally active HIV reservoirs. A higher percentage of HIV Gag-specific CD8+ T cell cytotoxic response was associated with lower intact proviral DNA. Predictors of HIV rebound timing differed between early- versus chronic-treated participants, as the strongest reservoir predictor of time to HIV rebound was level of residual viremia in early-treated participants and intact DNA level in chronic-treated individuals. We also identified distinct sets of pre-treatment interruption viral, immune, and inflammatory markers that differentiated participants who had rapid versus slow rebound.CONCLUSIONThe results provide an in-depth overview of the complex interplay of viral, immunologic, and inflammatory predictors of viral rebound and demonstrate that the timing of ART initiation modifies the features of rapid and slow viral rebound.TRIAL REGISTRATIONClinicalTrials.gov NCT03001128FUNDINGNIH National Institute of Allergy and Infectious Diseases, Merck.

SARS-CoV-2 infection elucidates unique features of pregnancy-specific immunity

Pregnancy is a risk factor for increased severity of SARS-CoV-2 and other respiratory infections. The mechanisms underlying this risk have not been well-established, partly due to a limited understanding of how pregnancy shapes immune responses. To gain insight into the role of pregnancy in modulating immune responses at steady state and upon perturbation, we collected peripheral blood mononuclear cells (PBMC), plasma, and stool from 226 women, including 152 pregnant individuals (n = 96 with SARS-CoV-2 infection and n = 56 healthy controls) and 74 non-pregnant women (n = 55 with SARS-CoV-2 and n = 19 healthy controls). We found that SARS-CoV-2 infection was associated with altered T cell responses in pregnant compared to non-pregnant women. Differences included a lower percentage of memory T cells, a distinct clonal expansion of CD4-expressing CD8 + T cells, and the enhanced expression of T cell exhaustion markers, such as programmed cell death-1 (PD-1) and T cell immunoglobulin and mucin domain-3 (Tim-3), in pregnant women. We identified additional evidence of immune dysfunction in severely and critically ill pregnant women, including a lack of expected elevation in regulatory T cell (Treg) levels, diminished interferon responses, and profound suppression of monocyte function. Consistent with earlier data, we found maternal obesity was also associated with altered immune responses to SARS-CoV-2 infection, including enhanced production of inflammatory cytokines by T cells. Certain gut bacterial species were altered in pregnancy and upon SARS-CoV-2 infection in pregnant individuals compared to non-pregnant women. Shifts in cytokine and chemokine levels were also identified in the sera of pregnant individuals, most notably a robust increase of interleukin-27 (IL-27), a cytokine known to drive T cell exhaustion, in the pregnant uninfected control group compared to all non-pregnant groups. IL-27 levels were also significantly higher in uninfected pregnant controls compared to pregnant SARS-CoV-2-infected individuals. Using two different preclinical mouse models of inflammation-induced fetal demise and respiratory influenza viral infection, we found that enhanced IL-27 protects developing fetuses from maternal inflammation but renders adult female mice vulnerable to viral infection. These combined findings from human and murine studies reveal nuanced pregnancy-associated immune responses, suggesting mechanisms underlying the increased susceptibility of pregnant individuals to viral respiratory infections.

SARS-CoV-2 viral clearance and evolution varies by type and severity of immunodeficiency

Despite vaccination and antiviral therapies, immunocompromised individuals are at risk for prolonged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, but the immune defects that predispose an individual to persistent coronavirus disease 2019 (COVID-19) remain incompletely understood. In this study, we performed detailed viro-immunologic analyses of a prospective cohort of participants with COVID-19. The median times to nasal viral RNA and culture clearance in individuals with severe immunosuppression due to hematologic malignancy or transplant (S-HT) were 72 and 40 days, respectively, both of which were significantly longer than clearance rates in individuals with severe immunosuppression due to autoimmunity or B cell deficiency (S-A), individuals with nonsevere immunodeficiency, and nonimmunocompromised groups (P < 0.01). Participants who were severely immunocompromised had greater SARS-CoV-2 evolution and a higher risk of developing resistance against therapeutic monoclonal antibodies. Both S-HT and S-A participants had diminished SARS-CoV-2-specific humoral responses, whereas only the S-HT group had reduced T cell-mediated responses. This highlights the varied risk of persistent COVID-19 across distinct immunosuppressive conditions and suggests that suppression of both B and T cell responses results in the highest contributing risk of persistent infection.

Maternal SARS-CoV-2 impacts fetal placental macrophage programs and placenta-derived microglial models of neurodevelopment

The SARS-CoV-2 virus activates maternal and placental immune responses, which in the setting of other infections occurring during pregnancy are known to impact fetal brain development. The effects of maternal immune activation on neurodevelopment are mediated at least in part by fetal brain microglia. However, microglia are inaccessible for direct analysis, and there are no validated non-invasive surrogate models to evaluate in utero microglial priming and function. We have previously demonstrated shared transcriptional programs between microglia and Hofbauer cells (HBCs, or fetal placental macrophages) in mouse models. Here, we assessed the impact of maternal SARS-CoV-2 on HBCs isolated from term placentas using single-cell RNA-sequencing. We demonstrated that HBC subpopulations exhibit distinct cellular programs, with specific subpopulations differentially impacted by SARS-CoV-2. Assessment of differentially expressed genes implied impaired phagocytosis, a key function of both HBCs and microglia, in some subclusters. Leveraging previously validated models of microglial synaptic pruning, we showed that HBCs isolated from placentas of SARS-CoV-2 positive pregnancies can be transdifferentiated into microglia-like cells, with altered morphology and impaired synaptic pruning behavior compared to HBC models from negative controls. These findings suggest that HBCs isolated at birth can be used to create personalized cellular models of offspring microglial programming.

High-Dose Inhaled Nitric Oxide in Acute Hypoxemic Respiratory Failure Due to COVID-19: A Multicenter Phase II Trial

Rationale: The effects of high-dose inhaled nitric oxide on hypoxemia in coronavirus disease (COVID-19) acute respiratory failure are unknown. Objectives: The primary outcome was the change in arterial oxygenation (PaO2/FiO2) at 48 hours. The secondary outcomes included: time to reach a PaO2/FiO2.300mmHg for at least 24 hours, the proportion of participants with a PaO2/FiO2.300mmHg at 28 days, and survival at 28 and at 90 days. Methods: Mechanically ventilated adults with COVID-19 pneumonia were enrolled in a phase II, multicenter, single-blind, randomized controlled parallel-arm trial. Participants in the intervention arm received inhaled nitric oxide at 80 ppm for 48 hours, compared with the control group receiving usual care (without placebo). Measurements and Main Results: A total of 193 participants were included in the modified intention-to-treat analysis. The mean change in PaO2/FiO2 ratio at 48 hours was 28.3mmHg in the intervention group and 21.4mmHg in the control group (mean difference, 39.1mmHg; 95% credible interval [CrI], 18.1 to 60.3). The mean time to reach a PaO2/FiO2.300mmHg in the interventional group was 8.7 days, compared with 8.4 days for the control group (mean difference, 0.44; 95% CrI, 23.63 to 4.53). At 28 days, the proportion of participants attaining a PaO2/FiO2.300mmHg was 27.7% in the inhaled nitric oxide group and 17.2% in the control subjects (risk ratio, 2.03; 95% CrI, 1.11 to 3.86). Duration of ventilation and mortality at 28 and 90 days did not differ. No serious adverse events were reported. Conclusions: The use of high-dose inhaled nitric oxide resulted in an improvement of PaO2/FiO2 at 48 hours compared with usual care in adults with acute hypoxemic respiratory failure due to COVID-19.

Viral and host mediators of non-suppressible HIV-1 viremia

Non-suppressible HIV-1 viremia (NSV) is defined as persistent low-level viremia on antiretroviral therapy (ART) without evidence of ART non-adherence or significant drug resistance. Unraveling the mechanisms behind NSV would broaden our understanding of HIV-1 persistence. Here we analyzed plasma virus sequences in eight ART-treated individuals with NSV (88% male) and show that they are composed of large clones without evidence of viral evolution over time in those with longitudinal samples. We defined proviruses that match plasma HIV-1 RNA sequences as 'producer proviruses', and those that did not as 'non-producer proviruses'. Non-suppressible viremia arose from expanded clones of producer proviruses that were significantly larger than the genome-intact proviral reservoir of ART-suppressed individuals. Integration sites of producer proviruses were enriched in proximity to the activating H3K36me3 epigenetic mark. CD4+ T cells from participants with NSV demonstrated upregulation of anti-apoptotic genes and downregulation of pro-apoptotic and type I/II interferon-related pathways. Furthermore, participants with NSV showed significantly lower HIV-specific CD8+ T cell responses compared with untreated viremic controllers with similar viral loads. We identified potential critical host and viral mediators of NSV that may represent targets to disrupt HIV-1 persistence.

SARS-CoV-2 Virologic Rebound With Nirmatrelvir-Ritonavir Therapy : An Observational Study

BACKGROUND

Data are conflicting regarding an association between treatment of acute COVID-19 with nirmatrelvir-ritonavir (N-R) and virologic rebound (VR).

OBJECTIVE

To compare the frequency of VR in patients with and without N-R treatment for acute COVID-19.

DESIGN

Observational cohort study.

SETTING

Multicenter health care system in Boston, Massachusetts.

PARTICIPANTS

Ambulatory adults with acute COVID-19 with and without use of N-R.

INTERVENTION

Receipt of 5 days of N-R treatment versus no COVID-19 therapy.

MEASUREMENTS

The primary outcome was VR, defined as either a positive SARS-CoV-2 viral culture result after a prior negative result or 2 consecutive viral loads above 4.0 log10 copies/mL that were also at least 1.0 log10 copies/mL higher than a prior viral load below 4.0 log10 copies/mL.

RESULTS

Compared with untreated persons (n = 55), those taking N-R (n = 72) were older, received more COVID-19 vaccinations, and more commonly had immunosuppression. Fifteen participants (20.8%) taking N-R had VR versus 1 (1.8%) who was untreated (absolute difference, 19.0 percentage points [95% CI, 9.0 to 29.0 percentage points]; P = 0.001). All persons with VR had a positive viral culture result after a prior negative result. In multivariable models, only N-R use was associated with VR (adjusted odds ratio, 10.02 [CI, 1.13 to 88.74]; P = 0.038). Virologic rebound was more common among those who started therapy within 2 days of symptom onset (26.3%) than among those who started 2 or more days after symptom onset (0%) (P = 0.030). Among participants receiving N-R, those who had VR had prolonged shedding of replication-competent virus compared with those who did not have VR (median, 14 vs. 3 days). Eight of 16 participants (50% [CI, 25% to 75%]) with VR also reported symptom rebound; 2 were completely asymptomatic. No post-VR resistance mutations were detected.

LIMITATIONS

Observational study design with differences between the treated and untreated groups; positive viral culture result was used as a surrogate marker for risk for ongoing viral transmission.

CONCLUSION

Virologic rebound occurred in approximately 1 in 5 people taking N-R, often without symptom rebound, and was associated with shedding of replication-competent virus.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Safety and efficacy of inhaled interferon-β1a (SNG001) in adults with mild-to-moderate COVID-19: a randomized, controlled, phase II trial

Background

With the emergence of SARS-CoV-2 variants resistant to monoclonal antibody therapies and limited global access to therapeutics, the evaluation of novel therapeutics to prevent progression to severe COVID-19 remains a critical need.

Methods

Safety, clinical and antiviral efficacy of inhaled interferon-β1a (SNG001) were evaluated in a phase II randomized controlled trial on the ACTIV-2/A5401 platform (ClinicalTrials.govNCT04518410). Adult outpatients with confirmed SARS-CoV-2 infection within 10 days of symptom onset were randomized and initiated either orally inhaled nebulized SNG001 given once daily for 14 days (n = 110) or blinded pooled placebo (n = 110) between February 10 and August 18, 2021.

Findings

The proportion of participants reporting premature treatment discontinuation was 9% among SNG001 and 13% among placebo participants. There were no differences between participants who received SNG001 or placebo in the primary outcomes of treatment emergent Grade 3 or higher adverse events (3.6% and 8.2%, respectively), time to symptom improvement (median 13 and 9 days, respectively), or proportion with unquantifiable nasopharyngeal SARS-CoV-2 RNA at days 3 (28% [26/93] vs. 39% [37/94], respectively), 7 (65% [60/93] vs. 66% [62/94]) and 14 (91% [86/95] vs. 91% [83/81]). There were fewer hospitalizations with SNG001 (n = 1; 1%) compared with placebo (n = 7; 6%), representing an 86% relative risk reduction (p = 0.07). There were no deaths in either arm.

Interpretation

In this trial, SNG001 was safe and associated with a non-statistically significant decrease in hospitalization for COVID-19 pneumonia.

Funding

The ACTIV-2 platform study is funded by the NIH. Research reported in this publication was supported by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health under Award Number UM1 AI068634, UM1 AI068636 and UM1 AI106701. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Viral and immunologic evaluation of smokers with severe COVID-19

Smoking negatively affects B cell function and immunoglobulin levels, but it is unclear if this immune dysfunction contributes to the risk of severe COVID-19 in smokers. We evaluated binding IgM, IgA and IgG antibodies to spike and receptor binding domain antigens, and used a pseudovirus assay to quantify neutralization titers in a set of 27 patients with severe COVID-19. We found no significant differences between binding and neutralization antibody responses for people with a smoking history and people who never smoked. High plasma viral load, but not antibody titers, was linked to an increased risk of death. Humoral immune dysfunction was not a major driver of severe COVID-19 in smokers.

One Week of Oral Camostat Versus Placebo in Nonhospitalized Adults With Mild-to-Moderate Coronavirus Disease 2019: A Randomized Controlled Phase 2 Trial

BACKGROUND

Camostat inhibits severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in vitro. We studied the safety and efficacy of camostat in ACTIV-2/A5401, a phase 2/3 platform trial of therapeutics for COVID-19 in nonhospitalized adults.

METHODS

We conducted a phase 2 study in adults with mild-to-moderate COVID-19 randomized to oral camostat for 7 days or a pooled placebo arm. Primary outcomes were time to improvement in COVID-19 symptoms through day 28, proportion of participants with SARS-CoV-2 RNA below the lower limit of quantification (LLoQ) from nasopharyngeal swabs through day 14, and grade ≥3 treatment-emergent adverse events (TEAEs) through day 28.

RESULTS

Of 216 participants (109 randomized to camostat, 107 to placebo) who initiated study intervention, 45% reported ≤5 days of symptoms at study entry and 26% met the protocol definition of higher risk of progression to severe COVID-19. Median age was 37 years. Median time to symptom improvement was 9 days in both arms (P = .99). There were no significant differences in the proportion of participants with SARS-CoV-2 RNA

CONCLUSIONS

In a phase 2 study of nonhospitalized adults with mild-to-moderate COVID-19, oral camostat did not accelerate viral clearance or time to symptom improvement, or reduce hospitalizations or deaths. Clinical Trials Registration. ClinicalTrials.gov identifier: NCT04518410.

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Key Words

• COVID-19
• SARS-CoV-2
• camostat
• outpatient
• phase 2

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MESH Headings

• Humans
• Adult
• COVID-19
• SARS-CoV-2
• RNA, Viral
• Time Factors
• Treatment Outcome

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Grants

• UM1 AI069423 NIAID NIH HHS
• UM1 AI069424 NIAID NIH HHS
• UM1 AI069432 NIAID NIH HHS
• UL1 TR000124 NCATS NIH HHS
• UM1 AI068634 NIAID NIH HHS
• UM1 AI069481 NIAID NIH HHS
• U01 AI068636 NIAID NIH HHS
• UL1 TR001881 NCATS NIH HHS
• UM1 AI068636 NIAID NIH HHS
• UM1AI068636 NIH HHS
• UM1 AI106701 NIAID NIH HHS
• K08 AI155173 NIAID NIH HHS
• P30 AI060354 NIAID NIH HHS
• National Institute of Allergy and Infectious Diseases
• National Institutes of Health

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Affiliation(s)

Nikolaus Jilg Department of Medicine, Massachusetts General Hospital and Department of Medicine, Brigham Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
Kara W Chew Department of Medicine, University of California, Los Angeles, California, USA
Mark J Giganti Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
Eric S Daar Department of Medicine, University of California Los Angeles Center, Torrance, California, USA
David A Wohl Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
Arzhang Cyrus Javan Division of AIDS, National Institutes of Health, Rockville, Maryland, USA
Amy Kantor Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
Carlee Moser Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
Robert W Coombs Department of Medicine, University of Washington, Seattle, Washington, USA
Gene Neytman Quantum Clinical Trials, Miami Beach, Florida, USA
Keila Hoover Miami Clinical Research, Miami, Florida, USA
Atasi Jana Sagent Pharmaceuticals, Schaumburg, Illinois, USA
Phil A Hart Department of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
Alexander L Greninger Department of Medicine, University of Washington, Seattle, Washington, USA
Bob Szurgot Sagent Pharmaceuticals, Schaumburg, Illinois, USA
Joseph J Eron Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
Judith S Currier Department of Medicine, University of Los Angeles, Los Angeles, California, USA
Michael D Hughes Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
Davey M Smith Department of Medicine, University of California, San Diego, San Diego, California, USA
Jonathan Z Li Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA

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Pathways and Intersections: Multifaceted Approaches to Engage Individuals From Underrepresented and Marginalized Communities in HIV Research and Career Development

BACKGROUND

The underrepresentation of historically marginalized groups in the HIV research workforce is a barrier to reaching national Ending the Epidemic goals.

SETTING

The Harvard University Center for AIDS Research (HU CFAR) Diversity Equity and Inclusion Working Group (DEI WG) uses a multifaceted approach to enhance the field's diversity.

METHODS

We established a DEI WG to improve the recruitment, inclusion, and retention of underrepresented minorities (URMs) in HIV research. We use community-based, participatory processes to establish and expand education and outreach programs about HIV care and research to better connect the HU CFAR to communities affected by HIV. This article reports on the development of the WG in July 2022, progress in its first year, and future plans.

RESULTS

We have built a network of >50 investigators across the university for monthly meetings; partnered with existing research pathway programs for high school, undergraduate, and graduate students, directly supporting 7 new trainees and linking CFAR investigators to additional mentorship opportunities; and created 2-year Scholar Awards for 5 URM investigators in HIV. Planned work includes needs assessments for early-stage investigators to understand factors contributing to inclusion and retention and new pathway and outreach programming being developed with community partner minority-serving institutions.

CONCLUSIONS

The HU CFAR DEI WG strives to ensure that individuals from underrepresented, marginalized, and minoritized communities have an opportunity to contribute to HIV research and that research is informed by the needs of the communities affected by the epidemic. An intersectional approach should be incorporated into HIV research pathway initiatives.

Modeling the emergence of viral resistance for SARS-CoV-2 during treatment with an anti-spike monoclonal antibody

The COVID-19 pandemic has led to over 760 million cases and 6.9 million deaths worldwide. To mitigate the loss of lives, emergency use authorization was given to several anti-SARS-CoV-2 monoclonal antibody (mAb) therapies for the treatment of mild-to-moderate COVID-19 in patients with a high risk of progressing to severe disease. Monoclonal antibodies used to treat SARS-CoV-2 target the spike protein of the virus and block its ability to enter and infect target cells. Monoclonal antibody therapy can thus accelerate the decline in viral load and lower hospitalization rates among high-risk patients with susceptible variants. However, viral resistance has been observed, in some cases leading to a transient viral rebound that can be as large as 3-4 orders of magnitude. As mAbs represent a proven treatment choice for SARS-CoV-2 and other viral infections, evaluation of treatment-emergent mAb resistance can help uncover underlying pathobiology of SARS-CoV-2 infection and may also help in the development of the next generation of mAb therapies. Although resistance can be expected, the large rebounds observed are much more difficult to explain. We hypothesize replenishment of target cells is necessary to generate the high transient viral rebound. Thus, we formulated two models with different mechanisms for target cell replenishment (homeostatic proliferation and return from an innate immune response anti-viral state) and fit them to data from persons with SARS-CoV-2 treated with a mAb. We showed that both models can explain the emergence of resistant virus associated with high transient viral rebounds. We found that variations in the target cell supply rate and adaptive immunity parameters have a strong impact on the magnitude or observability of the viral rebound associated with the emergence of resistant virus. Both variations in target cell supply rate and adaptive immunity parameters may explain why only some individuals develop observable transient resistant viral rebound. Our study highlights the conditions that can lead to resistance and subsequent viral rebound in mAb treatments during acute infection.

Association Between Anterior Nasal and Plasma SARS-CoV-2 RNA Levels and Hospitalization or Death in Nonhospitalized Adults With Mild-to-Moderate COVID-19

BACKGROUND

There is little information regarding severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA as a predictor for clinical outcomes in outpatients with mild-to-moderate coronavirus disease 2019 (COVID-19).

METHODS

Anterior nasal (AN) and plasma SARS-CoV-2 RNA data from 2115 nonhospitalized adults who received monoclonal antibodies (mAbs) or placebo in the ACTIV-2/A5401 trial were analyzed for associations with hospitalization or death.

RESULTS

One hundred two participants were hospitalized or died through 28 days of follow-up. Higher day 0 (pretreatment) AN RNA was associated with increasing risk of hospitalization/death (risk ratio [RR], 1.24 per log10 copies/mL [95% confidence interval {CI}, 1.04-1.49]) among placebo recipients, ranging from 3% to 16% for <2 to ≥6 log10 copies/mL. Although only 1% had quantifiable levels, there was a similar trend across day 0 plasma RNA categories. Higher day 3 AN RNA was associated with subsequent hospitalization/death among placebo recipients (RR, 1.42 per log10 copies/mL [95% CI, 1.00-2.03]), but not mAb recipients (RR, 1.02 per log10 copies/mL [95% CI, 0.68-1.56]). The proportion of treatment effect (reduction in hospitalizations/deaths after day 3 for mAb vs placebo) explained by day 3 AN RNA was 8%.

CONCLUSIONS

SARS-CoV-2 RNA levels are predictive of hospitalization/death in the natural history setting, but AN RNA levels may not be a reliable surrogate marker of mAb treatment effect in COVID-19 trials. Clinical Trials Registration. NCT04518410.

Statistical Challenges When Analyzing SARS-CoV-2 RNA Measurements Below the Assay Limit of Quantification in COVID-19 Clinical Trials

Most clinical trials evaluating coronavirus disease 2019 (COVID-19) therapeutics include assessments of antiviral activity. In recently completed outpatient trials, changes in nasal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA levels from baseline were commonly assessed using analysis of covariance (ANCOVA) or mixed models for repeated measures (MMRM) with single imputation for results below assay lower limits of quantification (LLoQ). Analyzing changes in viral RNA levels with singly imputed values can lead to biased estimates of treatment effects. In this article, using an illustrative example from the ACTIV-2 trial, we highlight potential pitfalls of imputation when using ANCOVA or MMRM methods, and illustrate how these methods can be used when considering values Collapse

Key Words

• COVID-19
• SARS-CoV-2 RNA
• linear regression for censored data
• randomized trial

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MESH Headings

• Humans
• Antiviral Agents
• Biological Assay
• COVID-19
• RNA, Viral
• SARS-CoV-2/genetics

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Grants

• UM1 AI069424 NIAID NIH HHS
• UM1 AI068634 NIH HHS
• UM1 AI069481 NIAID NIH HHS
• UM1 AI106701 NIAID NIH HHS
• U01 AI069424 NIAID NIH HHS
• UM1 AI069412 NIAID NIH HHS
• UM1 AI068634 NIAID NIH HHS
• UM1 AI068636 NIAID NIH HHS
• National Institute of Allergy and Infectious Diseases
• National Institutes of Health

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Affiliation(s)

Carlee B Moser Center for Biostatistics in AIDS Research, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
Kara W Chew Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
Mark J Giganti Center for Biostatistics in AIDS Research, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
Jonathan Z Li Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, Massachusetts, USA
Evgenia Aga Center for Biostatistics in AIDS Research, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
Justin Ritz Center for Biostatistics in AIDS Research, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
Alexander L Greninger Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
Arzhang Cyrus Javan National Institutes of Health, Rockville, Maryland, USA
Rachel Bender Ignacio Department of Medicine, University of Washington, Seattle, Washington, USA
Eric S Daar Lundquist Institute at Harbor-University of California, Los Angeles Medical Center, Torrance, California, USA
David A Wohl Department of Medicine, Chapel Hill School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
Judith S Currier Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
Joseph J Eron Department of Medicine, Chapel Hill School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
Davey M Smith Department of Medicine, University of California, San Diego, La Jolla, California, USA
Michael D Hughes Center for Biostatistics in AIDS Research, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA Department of Biostatistics, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA

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Anamnestic humoral correlates of immunity across SARS-CoV-2 variants of concern

While immune correlates against SARS-CoV-2 are typically defined at peak immunogenicity following vaccination, immunologic responses that expand selectively during the anamnestic response following infection can provide mechanistic and detailed insights into the immune mechanisms of protection. Moreover, whether anamnestic correlates are conserved across variants of concern (VOC), including the Delta and more distant Omicron VOC, remains unclear. To define the anamnestic correlates of immunity, across VOCs, we deeply profiled the humoral immune response in individuals infected with sequence-confirmed Delta or Omicron VOC after completing the vaccination series. While limited acute N-terminal domain and receptor-binding domain (RBD)-specific immune expansion was observed following breakthrough infection, a significant immunodominant expansion of opsonophagocytic Spike-specific antibody responses focused largely on the conserved S2-domain of SARS-CoV-2 was observed. This S2-specific functional humoral response continued to evolve over 2-3 weeks following Delta or Omicron breakthrough, targeting multiple VOCs and common coronaviruses. Strong responses were observed on the fusion peptide (FP) region and the heptad repeat 1 (HR1) region adjacent to the RBD. Notably, the FP is highly conserved across SARS-related coronaviruses and even non-SARS-related betacoronavirus. Taken together, our results point to a critical role of highly conserved, functional S2-specific responses in the anamnestic antibody response to SARS-CoV-2 infection across VOCs. These humoral responses linked to virus clearance can guide next-generation vaccine-boosting approaches to confer broad protection against future SARS-related coronaviruses. IMPORTANCE The Spike protein of SARS-CoV-2 is the primary target of antibody-based recognition. Selective pressures, be it the adaption to human-to-human transmission or evasion of previously acquired immunity, have spurred the emergence of variants of the virus such as the Delta and Omicron lineages. Therefore, understanding how antibody responses are expanded in breakthrough cases of previously vaccinated individuals can provide insights into key correlates of protection against current and future variants. Here, we show that vaccinated individuals who had documented COVID-19 breakthrough showed anamnestic antibody expansions targeting the conserved S2 subdomain of Spike, particularly within the fusion peptide region. These S2-directed antibodies were highly leveraged for non-neutralizing, phagocytic functions and were similarly expanded independent of the variant. We propose that through deep profiling of anamnestic antibody responses in breakthrough cases, we can identify antigen targets susceptible to novel monoclonal antibody therapy or vaccination-boosting strategies.

Long COVID After Bamlanivimab Treatment

BACKGROUND

Prospective evaluations of long COVID in outpatients with coronavirus disease 2019 (COVID-19) are lacking. We aimed to determine the frequency and predictors of long COVID after treatment with the monoclonal antibody bamlanivimab in ACTIV-2/A5401.

METHODS

Data were analyzed from participants who received bamlanivimab 700 mg in ACTIV-2 from October 2020 to February 2021. Long COVID was defined as the presence of self-assessed COVID symptoms at week 24. Self-assessed return to pre-COVID health was also examined. Associations were assessed by regression models.

RESULTS

Among 506 participants, median age was 51 years. Half were female, 5% Black/African American, and 36% Hispanic/Latino. At 24 weeks, 18% reported long COVID and 15% had not returned to pre-COVID health. Smoking (adjusted risk ratio [aRR], 2.41 [95% confidence interval {CI}, 1.34- 4.32]), female sex (aRR, 1.91 [95% CI, 1.28-2.85]), non-Hispanic ethnicity (aRR, 1.92 [95% CI, 1.19-3.13]), and presence of symptoms 22-28 days posttreatment (aRR, 2.70 [95% CI, 1.63-4.46]) were associated with long COVID, but nasal severe acute respiratory syndrome coronavirus 2 RNA was not.

CONCLUSIONS

Long COVID occurred despite early, effective monoclonal antibody therapy and was associated with smoking, female sex, and non-Hispanic ethnicity, but not viral burden. The strong association between symptoms 22-28 days after treatment and long COVID suggests that processes of long COVID start early and may need early intervention.

CLINICAL TRIALS REGISTRATION

NCT04518410.

Immune Status and SARS-CoV-2 Viral Dynamics

Immunocompromised individuals are disproportionately affected by severe coronavirus disease 2019, but immune compromise is heterogenous, and viral dynamics may vary by the degree of immunosuppression. In this study, we categorized ACTIV-2/A5401 participants based on the extent of immunocompromise into none, mild, moderate, and severe immunocompromise. Moderate/severe immunocompromise was associated with higher nasal viral load at enrollment (adjusted difference in means: 0.47 95% confidence interval, .12-.83 log10 copies/mL) and showed a trend toward higher cumulative nasal RNA levels and plasma viremia compared to nonimmunocompromised individuals. Immunosuppression leads to greater viral shedding and altered severe acute respiratory syndrome coronavirus 2 viral decay kinetics. Clinical Trials Registration. NCT04518410.

Variant-Specific Viral Kinetics in Acute COVID-19

Understanding variant-specific differences in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral kinetics may explain differences in transmission efficiency and provide insights on pathogenesis and prevention. We evaluated SARS-CoV-2 kinetics from nasal swabs across multiple variants (Alpha, Delta, Epsilon, Gamma) in placebo recipients of the ACTIV-2/A5401 trial. Delta variant infection led to the highest maximum viral load and shortest time from symptom onset to viral load peak. There were no significant differences in time to viral clearance across the variants. Viral decline was biphasic with first- and second-phase decays having half-lives of 11 hours and 2.5 days, respectively, with differences among variants, especially in the second phase. These results suggest that while variant-specific differences in viral kinetics exist, post-peak viral load all variants appeared to be efficiently cleared by the host. Clinical Trials Registration. NCT04518410.

SARS-CoV-2 Viral Clearance and Evolution Varies by Extent of Immunodeficiency

Despite vaccination and antiviral therapies, immunocompromised individuals are at risk for prolonged SARS-CoV-2 infection, but the immune defects that predispose to persistent COVID-19 remain incompletely understood. In this study, we performed detailed viro-immunologic analyses of a prospective cohort of participants with COVID-19. The median time to nasal viral RNA and culture clearance in the severe hematologic malignancy/transplant group (S-HT) were 72 and 40 days, respectively, which were significantly longer than clearance rates in the severe autoimmune/B-cell deficient (S-A), non-severe, and non-immunocompromised groups (P<0.001). Participants who were severely immunocompromised had greater SARS-CoV-2 evolution and a higher risk of developing antiviral treatment resistance. Both S-HT and S-A participants had diminished SARS-CoV-2-specific humoral, while only the S-HT group had reduced T cell-mediated responses. This highlights the varied risk of persistent COVID-19 across immunosuppressive conditions and suggests that suppression of both B and T cell responses results in the highest contributing risk of persistent infection.

Phase 2 Safety and Antiviral Activity of SAB-185, a Novel Polyclonal Antibody Therapy for Nonhospitalized Adults With COVID-19

BACKGROUND

SAB-185, a novel fully human IgG polyclonal immunoglobulin product, underwent phase 2 evaluation for nonhospitalized adults with mild-moderate coronavirus disease 2019 (COVID-19).

METHODS

Participants received intravenous SAB-185 3840 units/kg (low-dose) or placebo, or 10 240 units/kg (high-dose) or placebo. Primary outcome measures were nasopharyngeal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA < lower limit of quantification (LLOQ) at study days 3, 7, and 14, time to symptomatic improvement, and safety through day 28.

RESULTS

Two-hundred thirteen participants received low-dose SAB-185/placebo (n = 107/106) and 215 high-dose SAB-185/placebo (n = 110/105). The proportions with SARS-CoV-2 RNA < LLOQ were higher for SAB-185 versus placebo at days 3 and 7 and similar at day 14, and significantly higher at day 7 for high-dose SAB-185 versus placebo only, relative risk 1.23 (95% confidence interval, 1.01-1.49). At day 3, SARS-CoV-2 RNA levels were lower with low-dose and high-dose SAB-185 versus placebo: differences in medians of -0.78 log10 copies/mL (P = .08) and -0.71 log10 copies/mL (P = .10), respectively. No difference was observed in time to symptom improvement: median 11/10 days (P = .24) for low-dose SAB-185/placebo and 8/10 days (P = .50) for high-dose SAB-185/placebo. Grade ≥3 adverse events occurred in 5%/13% of low-dose SAB-185/placebo and 9%/12% of high-dose SAB-185/placebo.

CONCLUSIONS

SAB-185 was safe and generally well tolerated and demonstrated modest antiviral activity in predominantly low-risk nonhospitalized adults with COVID-19. Clinical Trials Registration. NCT04518410.

SARS-CoV-2 virologic rebound with nirmatrelvir-ritonavir therapy

Objective

To compare the frequency of replication-competent virologic rebound with and without nirmatrelvir-ritonavir treatment for acute COVID-19. Secondary aims were to estimate the validity of symptoms to detect rebound and the incidence of emergent nirmatrelvir-resistance mutations after rebound.

Design

Observational cohort study.

Setting

Multicenter healthcare system in Boston, Massachusetts.

Participants

We enrolled ambulatory adults with a positive COVID-19 test and/or a prescription for nirmatrelvir-ritonavir.

Exposures

Receipt of 5 days of nirmatrelvir-ritonavir treatment versus no COVID-19 therapy.

Main Outcome and Measures

The primary outcome was COVID-19 virologic rebound, defined as either (1) a positive SARS-CoV-2 viral culture following a prior negative culture or (2) two consecutive viral loads ≥4.0 log10 copies/milliliter after a prior reduction in viral load to <4.0 log10 copies/milliliter.

Results

Compared with untreated individuals (n=55), those taking nirmatrelvir-ritonavir (n=72) were older, received more COVID-19 vaccinations, and were more commonly immunosuppressed. Fifteen individuals (20.8%) taking nirmatrelvir-ritonavir experienced virologic rebound versus one (1.8%) of the untreated (absolute difference 19.0% [95%CI 9.0-29.0%], P=0.001). In multivariable models, only N-R was associated with VR (AOR 10.02, 95%CI 1.13-88.74). VR occurred more commonly among those with earlier nirmatrelvir-ritonavir initiation (29.0%, 16.7% and 0% when initiated days 0, 1, and ≥2 after diagnosis, respectively, P=0.089). Among participants on N-R, those experiencing rebound had prolonged shedding of replication-competent virus compared to those that did not rebound (median: 14 vs 3 days). Only 8/16 with virologic rebound reported worsening symptoms (50%, 95%CI 25%-75%); 2 were completely asymptomatic. We detected no post-rebound nirmatrelvir-resistance mutations in the NSP5 protease gene.

Conclusions and Relevance

Virologic rebound occurred in approximately one in five people taking nirmatrelvir-ritonavir and often occurred without worsening symptoms. Because it is associated with replication-competent viral shedding, close monitoring and potential isolation of those who rebound should be considered.

Current HIV/SIV Reservoir Assays for Preclinical and Clinical Applications: Recommendations from the Experts 2022 NIAID Workshop Summary

Since the first HIV-cured person was reported in 2009, a strong interest in developing highly sensitive HIV and SIV reservoir assays has emerged. In particular, the question arose about the comparative value of state-of-the-art assays to measure and characterize the HIV reservoir, and how these assays can be applied to accurately detect changes in the reservoir during efforts to develop a cure for HIV infection. Second, it is important to consider the impact on the outcome of clinical trials if these relatively new HIV reservoir assays are incorporated into clinical trial endpoints and/or used for clinical decision-making. To understand the advantages and limitations and the regulatory implications of HIV reservoir assays, the National Institute of Allergy and Infectious Diseases (NIAID) sponsored and convened a meeting on September 16, 2022, to discuss the state of knowledge concerning these questions and best practices for selecting HIV reservoir assays for a particular research question or clinical trial protocol.

Carbohydrate Loading and Aspiration Risk in Bariatric Patients: Safety in Preoperative Enhanced Recovery Protocols

BACKGROUND

Enhanced recovery protocols have been developed to improve perioperative outcomes; however, there is ongoing concern for aspiration with recent oral intake in patients with obesity, who may be predisposed to impaired gastrointestinal motility and greater gastric volumes. We aim to study the safety of a 300-mL preoperative carbohydrate-loading drink preceding bariatric surgery.

STUDY DESIGN

Data were collected prospectively from patients undergoing primary bariatric surgery. All bariatric patients at our institution are prescribed a proton pump inhibitor for 4 weeks before surgery and undergo a screening preoperative esophagogastroduodenoscopy (EGD) before surgery with a traditional 8-hour fast (NOCARB), followed by an intraoperative day-of-operation EGD with carbohydrate loading (CARB) 2 to 4 hours before incision. Gastric volumes and pH are measured after being endoscopically suctioned via direct visualization during both settings.

RESULTS

We identified 203 patients: 94 patients (46.3%) in the CARB group and 109 patients (53.7%) in the NOCARB group. The patients were 82.3% female with a mean age of 42.8 years and average BMI of 41.7 kg/m 2 . There was no difference in gastric volume between NOCARB and CARB (17.0 vs 16.1 mL, p = 0.59). The NOCARB group had lower pH values than the CARB group (2.8 vs 3.8, p = 0.001). Subset analysis of 23 patients who had measurements on both screening and intraoperative EGD revealed lower gastric volumes in CARB patients (13.3 vs 18.3, p < 0.0001).

CONCLUSIONS

When included in an enhanced recovery protocol, proton pump inhibitor use and preoperative carbohydrate loading 2 to 4 hours before bariatric surgery does not increase aspiration risk based on gastric volumes and pH and should be strongly considered in all eligible bariatric patients.

Cell culture systems for isolation of SARS-CoV-2 clinical isolates and generation of recombinant virus

A simple and robust cell culture system is essential for generating authentic SARS-CoV-2 stocks for evaluation of viral pathogenicity, screening of antiviral compounds, and preparation of inactivated vaccines. Evidence suggests that Vero E6, a cell line commonly used in the field to grow SARS-CoV-2, does not support efficient propagation of new viral variants and triggers rapid cell culture adaptation of the virus. We generated a panel of 17 human cell lines overexpressing SARS-CoV-2 entry factors and tested their ability to support viral infection. Two cell lines, Caco-2/AT and HuH-6/AT, demonstrated exceptional susceptibility, yielding highly concentrated virus stocks. Notably, these cell lines were more sensitive than Vero E6 cells in recovering SARS-CoV-2 from clinical specimens. Further, Caco-2/AT cells provided a robust platform for producing genetically reliable recombinant SARS-CoV-2 through a reverse genetics system. These cellular models are a valuable tool for the study of SARS-CoV-2 and its continuously emerging variants.

Autologous neutralizing antibodies increase with early antiretroviral therapy and shape HIV rebound after treatment interruption

Early initiation of antiretroviral therapy (ART) alters viral rebound kinetics after analytic treatment interruption (ATI) and may play a role in promoting HIV-1 remission. Autologous neutralizing antibodies (aNAbs) represent a key adaptive immune response in people living with HIV-1. We aimed to investigate the role of aNAbs in shaping post-ATI HIV-1 rebound variants. We performed single-genome amplification of HIV-1 env from pre-ART and post-ATI plasma samples of 12 individuals who initiated ART early after infection. aNAb activity was quantified using pseudoviruses derived from the most common plasma variant, and the serum dilution that inhibited 50% of viral infections was determined. aNAb responses matured while participants were on suppressive ART, because on-ART plasma and purified immunoglobulin G (IgG) demonstrated improved neutralizing activity against pre-ART HIV-1 strains when compared with pre-ART plasma or purified IgG. Post-ATI aNAb responses exerted selective pressure on the rebounding viruses, because the post-ATI HIV-1 strains were more resistant to post-ATI plasma neutralization compared with the pre-ART virus. Several pre-ATI features distinguished post-treatment controllers from noncontrollers, including an infecting HIV-1 sequence that was more similar to consensus HIV-1 subtype B, more restricted proviral diversity, and a stronger aNAb response. Post-treatment control was also associated with the evolution of distinct N-glycosylation profiles in the HIV-1 envelope. In summary, aNAb responses appeared to mature after early initiation of ART and applied selective pressure on rebounding viruses. The combination of aNAb activity with select HIV-1 sequence and reservoir features identified individuals with a greater chance of post-treatment control.

Safety and Efficacy of Combination SARS-CoV-2 Neutralizing Monoclonal Antibodies Amubarvimab Plus Romlusevimab in Nonhospitalized Patients With COVID-19

BACKGROUND

Development of safe and effective SARS-CoV-2 therapeutics is a high priority. Amubarvimab and romlusevimab are noncompeting anti-SARS-CoV-2 monoclonal antibodies with an extended half-life.

OBJECTIVE

To assess the safety and efficacy of amubarvimab plus romlusevimab.

DESIGN

Randomized, placebo-controlled, phase 2 and 3 platform trial. (ClinicalTrials.gov: NCT04518410).

SETTING

Nonhospitalized patients with COVID-19 in the United States, Brazil, South Africa, Mexico, Argentina, and the Philippines.

PATIENTS

Adults within 10 days onset of symptomatic SARS-CoV-2 infection who are at high risk for clinical progression.

INTERVENTION

Combination of monoclonal antibodies amubarvimab plus romlusevimab or placebo.

MEASUREMENTS

Nasopharyngeal and anterior nasal swabs for SARS-CoV-2, COVID-19 symptoms, safety, and progression to hospitalization or death.

RESULTS

Eight-hundred and seven participants who initiated the study intervention were included in the phase 3 analysis. Median age was 49 years (quartiles, 39 to 58); 51% were female, 18% were Black, and 50% were Hispanic or Latino. Median time from symptom onset at study entry was 6 days (quartiles, 4 to 7). Hospitalizations and/or death occurred in 9 (2.3%) participants in the amubarvimab plus romlusevimab group compared with 44 (10.7%) in the placebo group, with an estimated 79% reduction in events (P < 0.001). This reduction was similar between participants with 5 or less and more than 5 days of symptoms at study entry. Grade 3 or higher treatment-emergent adverse events through day 28 were seen less frequently among participants randomly assigned to amubarvimab plus romlusevimab (7.3%) than placebo (16.1%) (P < 0.001), with no severe infusion reactions or drug-related serious adverse events.

LIMITATION

The study population was mostly unvaccinated against COVID-19 and enrolled before the spread of Omicron variants and subvariants.

CONCLUSION

Amubarvimab plus romlusevimab was safe and significantly reduced the risk for hospitalization and/or death among nonhospitalized adults with mild to moderate SARS-CoV-2 infection at high risk for progression to severe disease.

PRIMARY FUNDING SOURCE

National Institute of Allergy and Infectious Diseases of the National Institutes of Health.

S:D614G and S:H655Y are gateway mutations that act epistatically to promote SARS-CoV-2 variant fitness

SARS-CoV-2 variants bearing complex combinations of mutations that confer increased transmissibility, COVID-19 severity, and immune escape, were first detected after S:D614G had gone to fixation, and likely originated during persistent infection of immunocompromised hosts. To test the hypothesis that S:D614G facilitated emergence of such variants, S:D614G was reverted to the ancestral sequence in the context of sequential Spike sequences from an immunocompromised individual, and within each of the major SARS-CoV-2 variants of concern. In all cases, infectivity of the S:D614G revertants was severely compromised. The infectivity of atypical SARS-CoV-2 lineages that propagated in the absence of S:D614G was found to be dependent upon either S:Q613H or S:H655Y. Notably, Gamma and Omicron variants possess both S:D614G and S:H655Y, each of which contributed to infectivity of these variants. Among sarbecoviruses, S:Q613H, S:D614G, and S:H655Y are only detected in SARS-CoV-2, which is also distinguished by a polybasic S1/S2 cleavage site. Genetic and biochemical experiments here showed that S:Q613H, S:D614G, and S:H655Y each stabilize Spike on virions, and that they are dispensable in the absence of S1/S2 cleavage, consistent with selection of these mutations by the S1/S2 cleavage site. CryoEM revealed that either S:D614G or S:H655Y shift the Spike receptor binding domain (RBD) towards the open conformation required for ACE2-binding and therefore on pathway for infection. Consistent with this, an smFRET reporter for RBD conformation showed that both S:D614G and S:H655Y spontaneously adopt the conformation that ACE2 induces in the parental Spike. Data from these orthogonal experiments demonstrate that S:D614G and S:H655Y are convergent adaptations to the polybasic S1/S2 cleavage site which stabilize S1 on the virion in the open RBD conformation and act epistatically to promote the fitness of variants bearing complex combinations of clinically significant mutations.

Safety and Efficacy of Combined Tixagevimab and Cilgavimab Administered Intramuscularly or Intravenously in Nonhospitalized Patients With COVID-19: 2 Randomized Clinical Trials

Importance

Development of effective, scalable therapeutics for SARS-CoV-2 is a priority.

Objective

To test the efficacy of combined tixagevimab and cilgavimab monoclonal antibodies for early COVID-19 treatment.

Design, Setting, and Participants

Two phase 2 randomized blinded placebo-controlled clinical trials within the Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV)-2/A5401 platform were performed at US ambulatory sites. Nonhospitalized adults 18 years or older within 10 days of positive SARS-CoV-2 test and symptom onset were eligible and were enrolled from February 1 to May 31, 2021.

Interventions

Tixagevimab-cilgavimab, 300 mg (150 mg of each component) given intravenously (IV) or 600 mg (300 mg of each component) given intramuscularly (IM) in the lateral thigh, or pooled placebo.

Main Outcomes and Measures

Coprimary outcomes were time to symptom improvement through 28 days; nasopharyngeal SARS-CoV-2 RNA below the lower limit of quantification (LLOQ) on days 3, 7, or 14; and treatment-emergent grade 3 or higher adverse events through 28 days.

Results

A total of 229 participants were randomized for the IM study and 119 were randomized for the IV study. The primary modified intention-to-treat population included 223 participants who initiated IM tixagevimab-cilgavimab (n = 106) or placebo treatment (n = 117) (median age, 39 [IQR, 30-48] years; 113 [50.7%] were men) and 114 who initiated IV tixagevimab-cilgavimab (n = 58) or placebo treatment (n = 56) (median age, 44 [IQR, 35-54] years; 67 [58.8%] were women). Enrollment in the IV study was stopped early based on a decision to focus on IM product development. Participants were enrolled at a median of 6 (IQR, 4-7) days from COVID-19 symptom onset. Significant differences in time to symptom improvement were not observed for IM tixagevimab-cilgavimab vs placebo or IV tixagevimab-cilgavimab vs placebo. A greater proportion in the IM tixagevimab-cilgavimab arm (69 of 86 [80.2%]) than placebo (62 of 96 [64.6%]) had nasopharyngeal SARS-CoV-2 RNA below LLOQ at day 7 (adjusted risk ratio, 1.33 [95% CI, 1.12-1.57]) but not days 3 and 14; the joint test across time points favored treatment (P = .003). Differences in the proportion below LLOQ were not observed for IV tixagevimab-cilgavimab vs placebo at any of the specified time points. There were no safety signals with either administration route.

Conclusions

In these 2 phase 2 randomized clinical trials, IM or IV tixagevimab-cilgavimab was safe but did not change time to symptom improvement. Antiviral activity was more evident in the larger IM trial.

Trial Registration

ClinicalTrials.gov Identifier: NCT04518410.

Viral and Host Mediators of Non-Suppressible HIV-1 Viremia

Non-suppressible HIV-1 viremia (NSV) can occur in persons with HIV despite adherence to combination antiretroviral therapy (ART) and in the absence of significant drug resistance. Here, we show that plasma NSV sequences are comprised primarily of large clones without evidence of viral evolution over time. We defined proviruses that contribute to plasma viremia as "producer", and those that did not as "non-producer". Compared to ART-suppressed individuals, NSV participants had a significantly larger producer reservoir. Producer proviruses were enriched in chromosome 19 and in proximity to the activating H3K36me3 epigenetic mark. CD4+ cells from NSV participants demonstrated upregulation of anti-apoptotic genes and downregulation of pro-apoptotic and type I/II interferon-related pathways. Furthermore, NSV participants showed no elevation in HIV-specific CD8+ cell responses and producer proviruses were enriched for HLA escape mutations. We identified critical host and viral mediators of NSV that represent potential targets to disrupt HIV persistence and promote viral silencing.

Diagnostic TR-FRET assays for detection of antibodies in patient samples

Serological assays are important diagnostic tools for surveying exposure to the pathogen, monitoring immune response post vaccination, and managing spread of the infectious agent among the population. Current serological laboratory assays are often limited because they require the use of specialized laboratory technology and/or work with a limited number of sample types. Here, we evaluate an alternative by developing time-resolved Förster resonance energy transfer (TR-FRET) homogeneous assays that exhibited exceptional versatility, scalability, and sensitivity and outperformed or matched currently used strategies in terms of sensitivity, specificity, and precision. We validated the performance of the assays measuring total immunoglobulin G (IgG) levels; antibodies against severe acute respiratory syndrome coronavirus (SARS-CoV) or Middle Eastern respiratory syndrome (MERS)-CoV spike (S) protein; and SARS-CoV-2 S and nucleocapsid (N) proteins and applied it to several large sample sets and real-world applications. We further established a TR-FRET-based ACE2-S competition assay to assess the neutralization propensity of the antibodies. Overall, these TR-FRET-based serological assays can be rapidly extended to other antigens and are compatible with commonly used plate readers.

Statistical Challenges when Analyzing SARS-CoV-2 RNA Measurements Below the Assay Limit of Quantification in COVID-19 Clinical Trials

Most clinical trials evaluating COVID-19 therapeutics include assessments of antiviral activity. In recently completed outpatient trials, changes in nasal SARS-CoV-2 RNA levels from baseline were commonly assessed using analysis of covariance (ANCOVA) or mixed models for repeated measures (MMRM) with single-imputation for results below assay lower limits of quantification (LLoQ). Analyzing changes in viral RNA levels with singly-imputed values can lead to biased estimates of treatment effects. In this paper, using an illustrative example from the ACTIV-2 trial, we highlight potential pitfalls of imputation when using ANCOVA or MMRM methods, and illustrate how these methods can be used when considering values Collapse

Key Words

• sars-cov-2 rna
• covid-19
• linear regression for censored data
• randomized trial

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MESH Headings Collapse

Grants

• UM1 AI068634 NIAID NIH HHS
• UM1 AI068636 NIAID NIH HHS
• UM1 AI106701 NIAID NIH HHS

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Affiliation(s)

Carlee B Moser Center for Biostatistics in AIDS Research, Harvard T.H. Chan School of Public Health, Boston, 02115, USA
Kara W Chew Department of Medicine, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, 90024, USA
Mark J Giganti Center for Biostatistics in AIDS Research, Harvard T.H. Chan School of Public Health, Boston, 02115, USA
Jonathan Z Li Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, 02139, USA
Evgenia Aga Center for Biostatistics in AIDS Research, Harvard T.H. Chan School of Public Health, Boston, 02115, USA
Justin Ritz Center for Biostatistics in AIDS Research, Harvard T.H. Chan School of Public Health, Boston, 02115, USA
Alexander L Greninger Department of Laboratory Medicine & Pathology, University of Washington, Seattle, 98195, USA
Arzhang Cyrus Javan National Institutes of Health, Rockville, 20852, USA Rachel Bender Ignacio, MD, MPH, Department of Medicine, University of Washington, Seattle, 98195, USA
Eric S Daar Lundquist Institute at Harbor-UCLA Medical Center, Torrance, 90502, USA David A Wohl, MD, Department of Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, 27599, USA
Judith S Currier Department of Medicine, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, 90024, USA
Joseph J Eron Department of Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, 27599, USA
Davey M Smith Department of Medicine, University of California, San Diego, La Jolla, 92093, USA
Michael D Hughes Department of Biostatistics and Center for Biostatistics in AIDS Research, Harvard T.H. Chan School of Public Health, Boston, 02115, USA For the ACTIV-2/A5401 Study Team

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HIV post-treatment controllers have distinct immunological and virological features

HIV post-treatment controllers (PTCs) are rare individuals who maintain low levels of viremia after stopping antiretroviral therapy (ART). Understanding the mechanisms of HIV post-treatment control will inform development of strategies aiming at achieving HIV functional cure. In this study, we evaluated 22 PTCs from 8 AIDS Clinical Trials Group (ACTG) analytical treatment interruption (ATI) studies who maintained viral loads ≤400 copies/mL for ≥24 wk. There were no significant differences in demographics or frequency of protective and susceptible human leukocyte antigen (HLA) alleles between PTCs and post-treatment noncontrollers (NCs, n = 37). Unlike NCs, PTCs demonstrated a stable HIV reservoir measured by cell-associated RNA (CA-RNA) and intact proviral DNA assay (IPDA) during analytical treatment interruption (ATI). Immunologically, PTCs demonstrated significantly lower CD4+ and CD8+ T cell activation, lower CD4+ T cell exhaustion, and more robust Gag-specific CD4+ T cell responses and natural killer (NK) cell responses. Sparse partial least squares discriminant analysis (sPLS-DA) identified a set of features enriched in PTCs, including a higher CD4+ T cell% and CD4+/CD8+ ratio, more functional NK cells, and a lower CD4+ T cell exhaustion level. These results provide insights into the key viral reservoir features and immunological profiles for HIV PTCs and have implications for future studies evaluating interventions to achieve an HIV functional cure.

Spike and nsp6 are key determinants of SARS-CoV-2 Omicron BA.1 attenuation

The SARS-CoV-2 Omicron variant is more immune evasive and less virulent than other major viral variants that have so far been recognized1-12. The Omicron spike (S) protein, which has an unusually large number of mutations, is considered to be the main driver of these phenotypes. Here we generated chimeric recombinant SARS-CoV-2 encoding the S gene of Omicron (BA.1 lineage) in the backbone of an ancestral SARS-CoV-2 isolate, and compared this virus with the naturally circulating Omicron variant. The Omicron S-bearing virus robustly escaped vaccine-induced humoral immunity, mainly owing to mutations in the receptor-binding motif; however, unlike naturally occurring Omicron, it efficiently replicated in cell lines and primary-like distal lung cells. Similarly, in K18-hACE2 mice, although virus bearing Omicron S caused less severe disease than the ancestral virus, its virulence was not attenuated to the level of Omicron. Further investigation showed that mutating non-structural protein 6 (nsp6) in addition to the S protein was sufficient to recapitulate the attenuated phenotype of Omicron. This indicates that although the vaccine escape of Omicron is driven by mutations in S, the pathogenicity of Omicron is determined by mutations both in and outside of the S protein.

Weight loss outcomes are not compromised in bariatric patients using cannabis

BACKGROUND

The legalization of cannabis in several states has led to increased documented use in the population. Bariatric surgery patients are no exception with estimates of anywhere from 6 to 8%. Cannabis is known to be associated with increased appetite, mood disorders, hyperphagia, and rarely, hyperemesis, which can potentially affect post-surgical weight loss. We aim to study the differences in bariatric surgery outcomes between cannabis users and non-users.

METHODS

A retrospective review identified patients undergoing bariatric surgery. Patients were divided into two groups, cannabis users (CU) and non-cannabis users (non-CU). Cannabis users (defined as using at least once weekly) and a group of non-users were called to obtain additional information. Primary outcome was weight loss. Secondary outcomes included incidence of post-operative nausea and vomiting (PONV), length of stay (LOS), readmission, and need for additional intervention.

RESULTS

A cohort of 364 sleeve gastrectomy patients met inclusion criteria, 31 (8.5%) CU and 333 (91.5%) non-CU. There was no difference in EWL between CU and non-CU at 1 week, 1 month, 3 months, 6 months, 9 months, 1 year, and 2 years. However, the CU group trended towards greater EWL at 3 years (52.9% vs. 38.1%, p = 0.094) and at 5 years (49.8% vs. 32.7%, p = 0.068). There were no significant differences between CU and non-CU with respect to either incidence or severity of PONV at one year after surgery or longer follow-up.

CONCLUSION

Cannabis users did not experience inferior weight loss after bariatric surgery despite common assumptions that appetite stimulation can lead to suboptimal weight loss outcomes. Our findings add to other work challenging this dogma. Larger, long-term, multicenter studies are warranted.

Symptom and Viral Rebound in Untreated SARS-CoV-2 Infection

BACKGROUND

Although symptom and viral rebound have been reported after nirmatrelvir-ritonavir treatment, the trajectories of symptoms and viral load during the natural course of COVID-19 have not been well described.

OBJECTIVE

To characterize symptom and viral rebound in untreated outpatients with mild to moderate COVID-19.

DESIGN

Retrospective analysis of participants in a randomized, placebo-controlled trial. (ClinicalTrials.gov: NCT04518410).

SETTING

Multicenter trial.

PATIENTS

563 participants receiving placebo in the ACTIV-2/A5401 (Adaptive Platform Treatment Trial for Outpatients With COVID-19) platform trial.

MEASUREMENTS

Participants recorded the severity of 13 symptoms daily between days 0 and 28. Nasal swabs were collected for SARS-CoV-2 RNA testing on days 0 to 14, 21, and 28. Symptom rebound was defined as a 4-point increase in total symptom score after improvement any time after study entry. Viral rebound was defined as an increase of at least 0.5 log10 RNA copies/mL from the immediately preceding time point to a viral load of 3.0 log10 copies/mL or higher. High-level viral rebound was defined as an increase of at least 0.5 log10 RNA copies/mL to a viral load of 5.0 log10 copies/mL or higher.

RESULTS

Symptom rebound was identified in 26% of participants at a median of 11 days after initial symptom onset. Viral rebound was detected in 31% and high-level viral rebound in 13% of participants. Most symptom and viral rebound events were transient, because 89% of symptom rebound and 95% of viral rebound events occurred at only a single time point before improving. The combination of symptom and high-level viral rebound was observed in 3% of participants.

LIMITATION

A largely unvaccinated population infected with pre-Omicron variants was evaluated.

CONCLUSION

Symptom or viral relapse in the absence of antiviral treatment is common, but the combination of symptom and viral rebound is rare.

PRIMARY FUNDING SOURCE

National Institute of Allergy and Infectious Diseases.

Nasal and Plasma Severe Acute Respiratory Syndrome Coronavirus 2 RNA Levels Are Associated With Timing of Symptom Resolution in the ACTIV-2 Trial of Nonhospitalized Adults With Coronavirus Disease 2019

Acute Coronavirus Disease 2019 symptoms limit daily activities, but little is known about its association with severe acute respiratory syndrome coronavirus 2 viral burden. In this exploratory analysis of placebo recipients in the ACTIV-2/A5401 platform trial, we showed that high anterior nasal RNA levels and detectable plasma RNA were associated with delayed symptom improvement. Clinical Trials Registration. https://clinicaltrials.gov/ct2/show/NCT04518410.

Characterization of Virologic Rebound Following Nirmatrelvir-Ritonavir Treatment for Coronavirus Disease 2019 (COVID-19)

We enrolled 7 individuals with recurrent symptoms or antigen test conversion following nirmatrelvir-ritonavir treatment. High viral loads (median 6.1 log10 copies/mL) were detected after rebound for a median of 17 days after initial diagnosis. Three had culturable virus for up to 16 days after initial diagnosis. No known resistance-associated mutations were identified.

Persistent Circulating Severe Acute Respiratory Syndrome Coronavirus 2 Spike Is Associated With Post-acute Coronavirus Disease 2019 Sequelae

The diagnosis of postacute sequelae of coronavirus disease 2019 (PASC) poses an ongoing medical challenge. To identify biomarkers associated with PASC we analyzed plasma samples collected from PASC and coronavirus disease 2019 patients to quantify viral antigens and inflammatory markers. We detect severe acute respiratory syndrome coronavirus 2 spike predominantly in PASC patients up to 12 months after diagnosis.