Optimization and evaluation of a live virus SARS-CoV-2 neutralization assay

Virus neutralization assays provide a means to quantitate functional antibody responses that block virus infection. These assays are instrumental in defining vaccine and therapeutic antibody potency, immune evasion by viral variants, and post-infection immunity. Here we describe the development, optimization and evaluation of a live virus microneutralization assay specific for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this assay, SARS-CoV-2 clinical isolates are pre-incubated with serial diluted antibody and added to Vero E6 cells. Replicating virus is quantitated by enzyme-linked immunosorbent assay (ELISA) targeting the SARS-CoV-2 nucleocapsid protein and the standardized 50% virus inhibition titer calculated. We evaluated critical test parameters that include virus titration, assay linearity, number of cells, viral dose, incubation period post-inoculation, and normalization methods. Virus titration at 96 hours was determined optimal to account for different growth kinetics of clinical isolates. Nucleocapsid protein levels directly correlated with virus inoculum, with the strongest correlation at 24 hours post-inoculation. Variance was minimized by infecting a cell monolayer, rather than a cell suspension. Neutralization titers modestly decreased with increasing numbers of Vero E6 cells and virus amount. Application of two different normalization models effectively reduced the intermediate precision coefficient of variance to <16.5%. The SARS-CoV-2 microneutralization assay described and evaluated here is based on the influenza virus microneutralization assay described by WHO, and are proposed as a standard assay for comparing neutralization investigations

A randomized placebo-controlled trial of convalescent plasma for adults hospitalized with COVID-19 pneumonia

Passive immunotherapy with convalescent plasma may be the only available agent during the early phases of a pandemic. Here, we report safety and efficacy of high-titer convalescent plasma for COVID-19 pneumonia. Double-blinded randomized multicenter placebo-controlled trial of adult patients hospitalized with COVID-19 pneumonia. The intervention was COVID-19 convalescent plasma and placebo was saline allocated 2:1. The primary outcome was clinical status 14 days after the intervention evaluated on a clinical ordinal scale. The trial was registered at ClinicalTrials.Gov, NCT04345289, 14/04/2020. The CCAP-2 trial was terminated prematurely due to futility. Of 147 patients randomized, we included 144 patients in the modified intention-to-treat population. The ordinal clinical status 14 days post-intervention was comparable between treatment groups (odds ratio (OR) 1.41, 95% confidence interval (CI) 0.72–2.09). Results were consistent when evaluating clinical progression on an individual level 14 days after intervention (OR 1.09; 95% CI 0.46–1.73). No significant differences in length of hospital stay, admission to ICU, frequency of severe adverse events or all-cause mortality during follow-up were found between the intervention and the placebo group. Infusion of convalescent plasma did not influence clinical progression, survival or length of hospitalization in patients with COVID-19 pneumonia

Pregnancy-associated bleeding and genetics:Five sequence variants in the myometrium and progesterone signaling pathway are associated with postpartum hemorrhage

Bleeding in early pregnancy and postpartum hemorrhage (PPH) bear substantial risks, with the former closely associated with pregnancy loss and the latter being the foremost cause of maternal death, underscoring the severity of these complications in maternal-fetal health. Here, we investigated the genetic variation underlying aspects of pregnancy-associated bleeding and identified five loci associated with PPH through a meta-analysis of 21,512 cases and 259,500 controls. Functional annotation analysis indicated candidate genes, HAND2, TBX3, and RAP2C/FRMD7, at three loci and showed that at each locus, associated variants were located within binding sites for progesterone receptors (PGR). Furthermore, there were strong genetic correlations with birth weight, gestational duration, and uterine fibroids. Early bleeding during pregnancy (28,898 cases and 302,894 controls) yielded no genome-wide association signals, but showed strong genetic correlation with a variety of human traits, indicative of polygenic and pleiotropic effects. Our results suggest that postpartum bleeding is related to myometrium dysregulation, whereas early bleeding is a complex trait related to underlying health and possibly socioeconomic status

Patient-Reported Outcomes in First-Line Antiretroviral Therapy: Results From NEAT001/ANRS143 Trial Comparing Darunavir/Ritonavir in Combination With Tenofovir/Emtricitabine or Raltegravir

Background: There are few data comparing patient-reported outcomes (PROs) in randomized trials of initial antiretroviral therapy. We present results from a substudy of the NEAT001/ ANRS143 trial. Methods: The randomized trial compared first-line DRV/r 800/100 mg once daily plus RAL 400 mg twice daily and DRV/r plus TDF/ FTC 245/200 mg once daily. Changes in PROs were assessed with 3 questionnaires: EuroQoL 5 domains (EQ-5D), Center for Epidemiologic Studies Depression (CES-D) scale, and HIV Treatment Satisfaction Questionnaire. Major depressive disorder (MDD) was defined as CES-D $16. General estimating equations were used to model change over 96 weeks in PROs from baseline. Results: Of the 805 participants, 797 (99substudy. Baseline PRO data were similar for the 2 randomized groups. Health status improved over time with a mean increase in EQ-5D visual analogue scale (VAS) of 8.0 by W96 [95to 9.4; P, 0.001], and no statistically significant differences between groups (difference of 0.3 on VAS score (95global P value$ 0.05 for all domains over follow-up). There was no significant difference between groups on CES-D [difference of 20.1 (95% CI: 21.3 to 1.1); P = 0.9], or MDD during follow-up, adjusted for baseline MDD (odds ratio = 0.98, 95% CI: 0.82 to 1.18; P = 0.9). RAL + DRV/r group had lower level of convenience (P = 0.03) and fitted less well into patients’ lifestyle (P = 0.007) than the TDF/FTC + DRV/r regimen, and was associated with lower treatment satisfaction [median score: 53 RAL + DRV/r vs 55 TDF/FTC + DRV/r (P = 0.001)]. Conclusion: PROs improved after starting antiretroviral therapy, with no statistically significant difference between groups. The lower satisfaction with RAL + DRV/r may be explained by twicedaily administration

Using clinical research networks to assess severity of an emerging influenza pandemic

BACKGROUND: Early clinical severity assessments during the 2009 influenza A H1N1 pandemic (pH1N1) overestimated clinical severity due to selection bias and other factors. We retrospectively investigated how to use data from the International Network for Strategic Initiatives in Global HIV Trials, a global clinical influenza research network, to make more accurate case fatality ratio (CFR) estimates early in a future pandemic, an essential part of pandemic response. METHODS: We estimated the CFR of medically attended influenza (CFRMA) as the product of probability of hospitalization given confirmed outpatient influenza and the probability of death given hospitalization with confirmed influenza for the pandemic (2009-2011) and post-pandemic (2012-2015) periods. We used literature survey results on health-seeking behavior to convert that estimate to CFR among all infected persons (CFRAR). RESULTS: During the pandemic period, 5.0% (3.1%-6.9%) of 561 pH1N1-positive outpatients were hospitalized. Of 282 pH1N1-positive inpatients, 8.5% (5.7%-12.6%) died. CFRMA for pH1N1 was 0.4% (0.2%-0.6%) in the pandemic period 2009-2011 but declined 5-fold in young adults during the post-pandemic period compared to the level of seasonal influenza in the post-pandemic period 2012-2015. CFR for influenza-negative patients did not change over time. We estimated the 2009 pandemic CFRAR to be 0.025%, 16-fold lower than CFRMA. CONCLUSIONS: Data from a clinical research network yielded accurate pandemic severity estimates, including increased severity among younger people. Going forward, clinical research networks with a global presence and standardized protocols would substantially aid rapid assessment of clinical severity