ABSTRACT
Background: Aim of the study was to analyze neutralizing activity against BA.5,BQ.1.1 and T cell response after 3rd booster dose [3BD (5th shot)] with BA.4/5 bivalent vaccine by hybrid immunity (HI) and CD4 count in advanced PLWH. Method(s): In PLWH with previous AIDS and/or CD4< 200/mm3 receiving 3BD (original strain/BA.4/5),immunogenicity was assessed at time of 3BD (T0) and at day 15 (T1) by microneutralization assay [MNA90] against Omicron BA.5, BQ.1.1 and by IFNgamma-ELISA. PLWH were stratified by HI vs. nHI and by CD4 count at T0 ( >or< 500/3). For crude mean comparisons, neutralizing antibodies (nAbs) were expressed in natural scale and fold changes, IFNgamma and all values for regression analyses in log2 scale, paired t-test used to test changes over T0-T1. Two 2-arms parallel trials were emulated: HI and CD4 count as exposure, log2 nAbs and IFNgamma as outcome. Average treatment effect (ATE) of the two exposures were estimated by marginal models weighted for potential confounders (age, CD4 nadir, years from AIDS;when HI was the exposure also CD4 count). Result(s): N=48 PLWH on ART, 15% female, median age 56 yrs, 45% >1 comorbidity, 87% with previous AIDS, median CD4 nadir 44 cell/mm3 (16-102), 98% with HIV-RNA < 50 cps/mL. A significant increase of nAbs against BA.5 (fold-increase 8.8,p< 0.0001) and BQ.1.1 (6.4, p< 0.0001) was observed from T0 to T1. At T1, in nHI (n=29), mean nAb was 176 and 53 against BA.5 and BQ.1.1, respectively, with a fold change reduction (FCR) vs BA.5 of 3.3;in HI (n=19), 496 and 128, respectively, with a FCR of 3.8 (Fig.1A). After controlling for confounders, HI was associated with a higher level of neutralizing response against BA.5 [ATE=1.17 log2 (95%CI 0.34;2.00), P=0.006] but not against BQ.1.1 [0.65 log2 (-0.18;1.48), p=0.124]. At T1, among PLWH with CD4 count< 500 (n=29), mean nAb was 290.8 and 83.9 against BA.5 and BQ.1.1, respectively, with a FCR of 3.4;in those with CD4 count >500 (n=19), 230.4 and 64.3, respectively, with a FCR of 3.6 (Fig. 1C).There was no impact of CD4 count on neutralization after controlling for potential confounding factors. No evidence for a difference between T0 and T1 was detected for IFNg (Fig.1B,D). Conclusion(s): In PLWH with advanced diseases, bivalent BA.5 3BD elicited strong neutralization against BA.5, and retained cross-neutralization against BQ.1.1, even if 3 times lower. HI but not CD4 count >500 appeared to enhance neutralization against BA.5. Importantly, bivalent vaccine appeared to have no effect on T-cell mediated response. (Figure Presented).
ABSTRACT
Background: SARS-CoV-2 Omicron sublineages exhibit evolving escape to in vitro neutralization by monoclonal antibodies (mAbs), with an unclear impact on in vivo treatment response. Our aim is to assess the impact of SARS-Cov-2 variants on the decline of viral load (VL) after treatment with 3 different drugs approved in EU for the early treatment of patients with mild-moderate COVID-19. Method(s): Post-hoc analysis from MONET (EudraCT: 2021-004188-28), phase 4 open-label RCT to assess efficacy of 500 mg intravenous sotrovimab (SOT), 600 mg intramuscular tixagevimab/cilgavimab (TIX/CIL) and oral 5-days course of NMV/r 300/100 mg BID, in non-hospitalized high-risk patients (pts) with early COVID-19. Pts' features were analyzed as binary variables by Chi-squared test. SARS-Cov-2 VL in nasopharyngeal swabs was carried out at randomization (1d) and at day 7 (7d) by cycle threshold value (Ct). Variant sequencing was performed at 1d. Ct variation was assessed by mixed effect log-linear model including random intercept at pts' level, log of Ct as independent variable, time, arm, viral variant as dependent variables, and interaction between time and arm. Multiple comparisons were adjusted by Bonferroni. Result(s): Among the 320 pts included between 4 Mar and 16 Nov, 2022, 108 (33.75%) received NMV/r, 103 (32.19%) TIX/CIL, and 109 (34.06%) SOT. Main characteristics were balanced across arms. Most of the pts were infected either with BA.2 (N=194;60.63%) or BA.4/BA.5 (N=100;31.25%) (Fig1A). VL at 1d was similar across the arms. In contrast, mean 7d VL was significantly lower in pts receiving NMV/r than in those receiving TIX/ CIL or SOT (P< 0.001) No significant VL variation was observed between the mAb arms (Fig1B). The analysis of the impact of viral variants suggests that while VL was significantly affected by variants (P=0.034), the superior effect of NMV/r over mAbs was homogeneous across all variant groups (P=0.290 for interaction) (Fig1C). Conclusion(s): Our study provides for the first time strong in vivo evidence that, when used against Omicron lineages, NMV/r exerts a stronger antiviral effect than mAbs. These results confirm previous in vitro evidence suggesting that mAbs may not retain neutralizing activity against all Omicron sublineages and provide preliminary information on how to use VL variation as a surrogate marker of efficacy. Further studies are needed to investigate whether the superior virologic activity of NMV/r over mAbs is confirmed for newly emerging variants, including BQ.1.1 or XBB.
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Background: Omicron subvariants questioned the efficacy of the approved therapies for the early COVID-19. In vitro data show that remdesivir (RDV), molnupiravir (MLN), and nirmatrelvir/ritonavir (NMV/r) all retained activity against all sub-lineages, while poor neutralizing activity was observed for Sotrovimab (SOT) and Tixagevimab/cilgavimab (TIX/CIL). No data about the risk of clinical failure or even in vivo antiviral activity are available. Method(s): Single-center observational comparison study enrolling all consecutive patients (pts) seen for care with a confirmed SARS-CoV-2 Omicron diagnosis and who met the AIFA criteria for eligibility for treatment with RDV, MLN, NMV/r, TIX/CIL, or SOT. Treatment allocation was subject to drug availability, time from symptoms onset, and comorbidities. Nasopharyngeal swab (NPS) VL was measured on day 1 (D1) and D7 and was expressed by log2 cycle threshold (CT) scale. Comparisons between treatment groups were made by Chi-square, and Wilcoxon paired tests. Primary endpoint was D1-D7 VL variation. Potential decrease in VL and average treatment effect (ATE) were calculated from fitting marginal linear regression models weighted for calendar month of drug initiation, duration of symptoms, and immunodeficiency using NMV/r as the comparator trial arm. Result(s): A total of 971 pts received treatments (SOT 321, MLN 231, NMV/r 211, TIX/CIL 70, and RDV 138): female 457 (47%), median age 67 yrs (IQR 56-78), 93% vaccinated;12% with negative baseline serology. At D1, median time from symptoms onset was 3 days (IQR 2,4). 379 (39%) pts were infected with BA.1, 215 (22%) with BA.2, 372 with BA.4/5 (38%), and 5 with BQ.1 (0,5%). D1 mean viral load was 4.02 log2. Adjusted analysis (ATE) showed that NMV/r significantly reduced VL compared to all the other drugs in pts infected with all sublineages, (Fig.1A-B) while less evidence for a difference vs. TIX/CIL was seen in those infected with BA.2 (p=0.05) (Fig.1 C-D). Conclusion(s): In this analysis of in vivo early VL reductions, NMV/r appears to be the drug showing the greatest antiviral activity, regardless of the underlying subvariant, perhaps with the exception of TIX/CIL in people infected with BA.2 for which there was less evidence for a difference. In the Omicron era, due to the high prevalence of vaccinated people and in absence of clinical events, VL is one of the possible alternative endpoints which guarantees adequate statistical power. Fig 1 SARS-CoV-2 RNA levels at D1 and D7 in patients treated with Nirmatrelvir/ ritonavir, Sotrovimab, Molnupiravir, Remdesivir, and Tixagevimab/cilgavimab. Dot-plots showing the comparison of viral loads detected at D1 and D7 and the variation of RNA levels observed between the two time-points by intervention in (A) all patients treated with Nirmatrelvir/ritonavir (n=211), Sotrovimab (n=321), or Molnupiravir (n=231), or Remdesivir (n=138), or Tixagevimab/ cilgavimab (n=136);(C) patients with Omicron BA.2 infection treated with Nirmatrelvir/ritonavir (n=58), Sotrovimab (n=81), or Molnupiravir (n=21), or Remdesivir (n=37), or Tixagevimab/cilgavimab (n=18);(D) patients with Omicron BA.4/5 infection treated with Nirmatrelvir/ritonavir (n=102), Sotrovimab (n=92), or Molnupiravir (n=110), or Remdesivir (n=16), or Tixagevimab/cilgavimab (n=52). Viral RNA levels are expressed as log2 CT values. The horizontal dashed line represents the limit of detection (CT: 40.0), values >=40 are considered negative. Mean of log2 CT values, and SD are shown in the graph. Statistical analysis of the differences in viral loads by intervention as compared to Nirmatrelvir/ritonavir was performed by Mann-Whitney test. Potential decrease in VL and average treatment effect (ATE) were calculated from fitting marginal linear regression models weighted for calendar month of drug initiation, duration of symptoms, and immunodeficiency using NMV/r as the comparator trial arm. Results are shown (B) for patients infected with all Omicron sublineages and (D) for those infected with Omicron BA.2 sublineage.
ABSTRACT
Background: In Italy in September 2021, administration of a booster shot (BS) of COVID-19 vaccine was approved for PLWH with advanced disease (current CD4 count<200 cell/mm3 and/or previous AIDS). The aim of this analysis was to investigate the degree of immunogenicity after BS by current CD4 count. Methods: In PLWH attending INMI Spallanzani Hospital in Rome, Italy and receiving a BS of BNT162b2 or mRNA-1273 >28 days after a complete mRNA vaccination cycle, immunogenicity was assessed at time of BS (T0) and at day 15 (T1) by anti-RBD CLIA, microneutralization assay [MNA90] and IFNγ production. Participants were stratified by CD4 count at T0 (severe immunodeficiency, SID: <200/mm3;minor immunodeficiency, MID: 200-500/mm3;no immunodeficiency, NID: >500/mm3). Immune response was defined: anti-RBD >7.1 BAU/mL, MNA90 titres >1:10 and IFNγ >12 pg/mL. A paired t-test was used to test overall changes (log2 scale) over T0-T1. ANOVA and truncated regression models were used to compare change in titers from T0 to T1, association between current CD4 count and the lack of immune response was determined by fitting a multivariable logistic regression adjusted for age, time from HIV diagnosis, CD4 nadir, cancer and HIV-RNA a T0. Results: We included 216 PLWH on ART (n=76 SID, n=96 MID, n=44 NID): median age 54 yrs (IQR 47-59), median CD4 nadir 45 cell/mm3 (20-122), 93% HIV-RNA <50 c/mL, 7yrs (3-12) since HIV diagnosis and 5yrs (2-8) since AIDS if diagnosed. Participants received BS after a median of 142 (132-156) days from second dose. Response rate was 95.5% in SID, 100% in MID, 100% in NID for anti-RBD (p=0.02);86.3%, 97.9% and 98.7% for nAbs (p=0.002), and 70%, 95.6% and 97.2% for IFNγ (p<0.0001). Overall we observed a significant increase of BS immunogenicity [anti RBD: mean Log2 4.5 (SD 1.9),p<0.0001;nAbs: 3.7 (2.2),p<0.0001;IFNγ: 0.77 (2.9),p=0.0003]. However, there was no evidence for a difference in mean change of humoral immunogenicity, anti-RBD, nAbs and IFNγ changes by CD4 count groups (Figure 1 A-C). A current CD4 count <200 cell/mm3 was not associated with the risk of failing to elicit neutralizing and cell-mediated response by logistic regression (Figure1D). Conclusion: A mRNA BS strongly boosted humoral response in PLWH with advanced disease, regardless of CD4 count at the time of booster. Although clinical implications of the observed immunological response remain uncertain, our data support the usefulness of BS in PLWH with immune dysregulation.
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Background: Few data are available about comparison of different monoclonal antibodies (MAbs) for COVID-19 in the real-world setting. We aim to compare effectiveness of bamlanivimab/etesevimab (BAM/ETE) versus (vs) casirivimab/imdevimab (CAS/IMD) and to estimate predictors of hospitalization/death. Methods: Observational analysis of all consecutive outpatients (pts) with mild/moderate COVID-19 enrolled within the AIFA access program in a single center in Rome, from March to October, 2021. At first baseline (BL) visit, RT-PCR from nasopharyngeal swab with cycle thereshold (CT) measurement and viral sequencing was performed. Pts received intravenous BAM/ETE (700/1400 mg) or CAS/IMD (1200/1200 mg) and were followed through day 30. Primary endpoint was hospitalization/death due to severe COVID-19 by day 30. Average treatment effect (ATE) in the multiplicative scale of the odds was the chosen estimand to compare the two treatments, adjusted for age, obesity, time from onset to infusion, median C-reactive protein (CRP), vaccination, variant of concern (VOC) and BL-CT. Predictors of clinical failure were explored by two different models of multivariable logistic regression. Results: 242 pts receiving BAM/ETE (n=76) or CAS/IMD (n=166) were included (male 54%;median age 65 yrs;median SpO2 97%;diabetes 12%;hypertension 40%;CVD 17%;COPD 26%;autoimmune diseases 12%;immunodeficiency 18%). Median time from symptoms onset to infusion was 4 days (IQR 3-6). No differences were observed between the two MAbs for BL characteristics except for BMI>35 (BAM/ETE 24%, CAS/IMD 12%), CRP (BAM/ETE 1.8, CAS/IMD 1.2), vaccination (BAM/ETE 26%, CAS/IMD 46%) and distribution of VOC (Alpha 46% BAM/ETE vs 22% CAS/IMD;Gamma 20% vs 7%;Delta 5% vs 55%). Proportion of patients with COVID-related hospitalization/death by day 30 was 12/76 (15.8%) for BAM/ETE and 6/166 (3.6%) for CAS/IMD. Estimate of causal effect of BAM/ETE exposure compared to CAS/IMD on primary end point by ATE is reported in Table 1a. Factors associated with an increased risk of clinical failure by fitting multivariable logistic regression were BMI >35 and P1/Gamma VOC;higher BL-CT was associated with a reduced risk (Table 1b-1c). Conclusion: In a real-life setting, receiving BAM/ETE was associated with a 4-fold higher risk of COVID-19 progression to hospitalization/death than CAS/IMD. SARS-CoV-2 P.1/Gamma, but not B.1617.2/Delta VOC, obesity and higher BL viral load also predicted an increased risk of clinical worsening.
ABSTRACT
SARS-CoV-2 serum neutralization assay represents the gold standard for assessing antibody-mediated protection in naturally infected and vaccinated individuals. In the present study, 662 serum samples collected from February 2020 to January 2021 from acute and convalescent COVID-19 patients were tested to determine neutralizing antibody (NAb) titers using a microneutralization test (MNT) for live SARS-CoV-2. Moreover, anti-SARS-CoV-2 IgG, IgA, and IgM directed against different viral antigens were measured by high-throughput automated platforms. We observed higher levels of NAbs in elderly (>60 years old) individuals and in patients presenting acute respiratory distress syndrome. SARS-CoV-2 NAbs develop as soon as five days from symptom onset and, despite a decline after the second month, persist for over 11 months, showing variable dynamics. Through correlation and receiver operating characteristic (ROC) curve analysis, we set up a testing algorithm, suitable for the laboratory workload, by establishing an optimal cutoff value of anti-SARS-CoV-2 IgG for convalescent plasma donors to exclude from MNT samples foreseen to have low/negative NAb titers and ineligible for plasma donation. Overall, MNT, although cumbersome and not suitable for routine testing of large sample sizes, remains the reference tool for the assessment of antibody-mediated immunity after SARS-CoV-2 infection. Smart testing algorithms may optimize the laboratory workflow to monitor antibody-mediated protection in COVID-19 patients, plasma donors, and vaccinated individuals.