Hyperimmune Globulins in COVID-19.

The COVID-19 pandemic, resulting from the emergence of the novel coronavirus SARS-CoV-2, posed unprecedented challenges to global health systems as no proven therapy was available. Initially, COVID-19 convalescent plasma (CCP) from recovered COVID-19 patients showed promise as a therapeutic option. However, the efficacy of this approach was closely correlated with the neutralizing antibody titer in the administered plasma and thus effectiveness was not always guaranteed. In response, hyperimmune immunoglobulins (hIG) derived from CCP obtained by apheresis from recovered or vaccinated individuals emerged as a potential alternative. hIG were purified through stringent chromatographic processing from CCP units and displayed varying results in clinical trials, although it seems likely that they improved outcomes compared to placebo or CCP at day 28, particularly in unvaccinated patients. The variability in the effect of hIG likely stems from factors such as the timing of outcome assessment, the administered dose of hIG, the patients' immunological background, and the matching between the variant infecting patients and the neutralization ability of the immunoglobulin batch, which depended on the timing of the CCP collection. Despite logistical challenges and high production costs, hIG showcase advantages over CCP, offering versatility in administration routes and eliminating the need for blood matching, thus facilitating administration in the community, and allowing for variant-specific preparations. hIG appear to be of particular importance in the treatment of immunocompromised patients and patients with persistent COVID-19, although studies in these populations are lacking. Non-human alternatives, such as equine-derived hIG and recombinant hIG, may provide a solution to the logistical challenges of large-scale hIG preparation. Further study is needed to explore these avenues. Establishing the infrastructure for large-scale hIG production independent of plasma donations emerges as a strategic approach for future pandemics, justifying exploration and promotion by health authorities.

Maor Y ，Zimhony O 《Current Topics in Microbiology and Immunology》

Production and Quality Assurance of Human Polyclonal Hyperimmune Immunoglobulins Against SARS-CoV-2.

The coronavirus disease 2019 (COVID-19) pandemic has highlighted the potential therapeutic value of early passive polyclonal immunotherapy using high-titer convalescent plasma (CCP). Human polyclonal hyperimmune immunoglobulin (HIG) has several advantages over CCP. Unlike CCP, HIG can provide standardized and controlled antibody content. It is also subjected to robust pathogen reduction rendering it virally safe and is purified by technologies demonstrated to preserve immunoglobulin neutralization capacity and Fc fragment integrity. This document provides an overview of current practices and guidance for the collection and testing of plasma rich in antibodies against Severe Acute Respiratory Coronavirus 2 (SARS-CoV-2) and its industrial fractionation for the manufacture of quality-assured and safe HIG. Considerations are also given to the production of HIG preparations in low- and middle-income countries.

Burnouf T ，Gathof B ，Bloch EM ，Bazin R ，de Angelis V ，Patidar GK ，Rastvorceva RMG ，Oreh A ，Goel R ，Rahimi-Levene N ，Hindawi S ，Al-Riyami AZ ，So-Osman C ，ISBT COVID-19 Convalescent Plasma Working Group (see the Appendix) ... -  《-》

Potent Anti-SARS-CoV-2 Efficacy of COVID-19 Hyperimmune Globulin from Vaccine-Immunized Plasma.

Coronavirus disease 2019 (COVID-19) remains a global public health threat. Hence, more effective and specific antivirals are urgently needed. Here, COVID-19 hyperimmune globulin (COVID-HIG), a passive immunotherapy, is prepared from the plasma of healthy donors vaccinated with BBIBP-CorV (Sinopharm COVID-19 vaccine). COVID-HIG shows high-affinity binding to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein, the receptor-binding domain (RBD), the N-terminal domain of the S protein, and the nucleocapsid protein; and blocks RBD binding to human angiotensin-converting enzyme 2 (hACE2). Pseudotyped and authentic virus-based assays show that COVID-HIG displays broad-spectrum neutralization effects on a wide variety of SARS-CoV-2 variants, including D614G, Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Kappa (B.1.617.1), Delta (B.1.617.2), and Omicron (B.1.1.529) in vitro. However, a significant reduction in the neutralization titer is detected against Beta, Delta, and Omicron variants. Additionally, assessments of the prophylactic and treatment efficacy of COVID-HIG in an Adv5-hACE2-transduced IFNAR-/- mouse model of SARS-CoV-2 infection show significantly reduced weight loss, lung viral loads, and lung pathological injury. Moreover, COVID-HIG exhibits neutralization potency similar to that of anti-SARS-CoV-2 hyperimmune globulin from pooled convalescent plasma. Overall, the results demonstrate the potential of COVID-HIG against SARS-CoV-2 infection and provide reference for subsequent clinical trials.

Yu D ，Li YF ，Liang H ，Wu JZ ，Hu Y ，Peng Y ，Li TJ ，Hou JF ，Huang WJ ，Guan LD ，Han R ，Xing YT ，Zhang Y ，Liu J ，Feng L ，Li CY ，Liang XL ，Ding YL ，Zhou ZJ ，Ji DM ，Wang FF ，Yu JH ，Deng K ，Xia DM ，Dong DM ，Hu HR ，Liu YJ ，Fu DX ，He YL ，Zhou DB ，Yang HC ，Jia R ，Ke CW ，Du T ，Xie Y ，Zhou R ，Li CS ，Wang ML ，Yang XM ... -  《Advanced Science》

Convalescent plasma and hyperimmune globulin therapy in COVID-19.

Cagdas D 《-》

High-titer post-vaccine COVID-19 convalescent plasma for immunocompromised patients during the first omicron surge.

Transplant and hematologic malignancy patients have high Coronavirus disease 2019 (COVID-19) mortality and impaired vaccination responses. Omicron variant evades several monoclonal antibodies previously used in immunocompromised patients. Polyclonal COVID-19 convalescent plasma (CCP) may provide broader neutralizing capacity against new variants at high titers. Vaccination increases severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) titer in convalescent donors. We conducted a retrospective chart review of hospitalized immunocompromised patients with COVID-19 who received high-titer CCP during the first omicron surge, collected from vaccinated donors within 6 months of pre-omicron COVID-19. Data on safety and outcomes were extracted. A total of 44 immunocompromised patients were included, 59.1% with solid organ transplant, 22.7% with hematopoietic cell transplant, 11.4% with hematologic malignancy, and 6.8% with autoimmune disease. Overall, 95% of CCP units transfused were from recently recovered and vaccinated donors and had SARS-CoV-2 antibody results 8- to 37-fold higher than the Food and Drug Administration's cutoff for high-titer CCP. There were two mild transfusion reactions. A total of 30-day mortality was 4.5%. There were no differences in 100-day mortality by underlying diagnosis, levels of immunosuppression, and timing of CCP administration. Patients with higher immunosuppression had significantly higher mean World Health Organization clinical progression scores at 30-day post-CCP compared to those with lower immunosuppression. CCP is a safe, globally available treatment for immunocompromised patients with COVID-19. Mortality was lower in our cohort than that of COVID-19 patients with similar immunocompromising conditions. Post-vaccine CCP with very high titers should be prioritized for study in immunocompromised patients. Post-vaccine CCP has the potential to keep pace with new variants by overcoming mutations at sufficiently high titer.

Tayyar R ，Wong LK ，Dahlen A ，Shu E ，Pandey S ，Liu AY ... -  《-》