Passive immunotherapies for the next influenza pandemic.

Influenzavirus is among the most relevant candidates for a next pandemic. We review here the phylogeny of former influenza pandemics, and discuss candidate lineages. After briefly reviewing the other existing antiviral options, we discuss in detail the evidences supporting the efficacy of passive immunotherapies against influenzavirus, with a focus on convalescent plasma.

Association between clinical symptoms during the COVID-19 infection and SARS-CoV-2 immunoglobulin G titers in COVID-19 convalescent whole-blood donors in China.

BACKGROUND: Limited studies have explored the association between clinical symptoms and titers of SARS-CoV-2 antibodies. STUDY DESIGN AND METHODS: In this cross-sectional study, whole-blood donors who had experienced a confirmed or suspected COVID-19 infection completed questionnaires at the time of blood donation. Plasma SARS-CoV-2 immunoglobulin G (IgG) titers were measured using an enzyme-linked immunosorbent assay. Logistic regression models were used to calculate odds ratios (ORs) for high-titer COVID-19 convalescent plasma (CCP) for each variable. RESULTS: Among the total 386 donors, 120 (31%) donors with IgG titers ≥1:160 were classified as high-titer donors. The multivariable ORs (95% confidence intervals [CIs]) for high titers were 2.33 (1.45-3.75), 2.11 (1.29-3.43), 1.10 (1.01-1.21), 1.19 (1.00-1.43), and 1.97 (1.05-3.71) for sore throat, cough, symptom count, fever duration, and low fever (compared with non-fever), respectively. No significant association was observed between other symptoms and medical visits and the odds of high-titer CCP. The association between high-titer CCP and fever duration was restricted to confirmed COVID-19-infected donors, while associations with sore throat and cough remained significant in suspected infected donors. In addition, medical visit was positively associated with high-titer CCP in suspected donors, but not in confirmed donors. In bootstrapped logistic regression models, the associations remained significant and reproducible for medical visit in suspected donors and for sore throat and cough in both suspected donors and total donors. DISCUSSION: Experiencing a sore throat and cough were associated with high-titer CCP in overall donors. We also identified sore throat, cough, and medical visits as potential predictors of high-titer CCP for suspected donors during the pandemic.

Experiences in the use of multiple doses of convalescent plasma in critically ill patients with COVID-19: An early phase 1 descriptive study.

Background: At the beginning of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, transfusion of coronavirus disease 2019 (COVID-19) convalescent plasma (CCP) emerged as a potential therapeutic strategy to help patients severely afflicted by COVID-19. The efficacy of CCP has been controversial as it depends on many variables pertaining to the plasma donor and the patient with COVID-19, for example, time of convalescence or symptoms onset. This feasibility and descriptive study aimed to assess the safety of multiple doses of CCP in mechanically ventilated, intubated patients with respiratory failure due to COVID-19. Methods: A cohort of 30 patients all experiencing severe respiratory failure and undergoing invasive mechanical ventilation in an intensive care unit, received up to five doses of 300-600 mL of CCP on alternate days (0, 2, 4, 6, and 8) until extubation, futility, or death. Results: Nineteen patients received five doses, seven received four, and four received two or three doses. At 28-day follow-up mark, 57% of patients recovered and were sent home, and the long-term mortality rate was 27%. Ten severe adverse events reported in the study were unrelated to CCP transfusion. Independent of the number of transfused doses, most patients had detectable levels of total and neutralizing antibodies in plasma. Conclusion: This study suggests that transfusion of multiple doses of CCP is safe. This strategy may represent a viable option for future studies, given the potential benefit of CCP transfusions during the early stages of infection in unvaccinated populations and in settings where monoclonal antibodies or antivirals are contraindicated or unavailable.

Characteristics and Motivational Factors of Whole Blood and Convalescent Plasma Donors during the SARS-CoV-2 Pandemic in Israel.

Demands for whole blood (WB) and COVID-19 convalescent plasma (CCP) donations during the SARS-CoV-2 (COVID-19) pandemic presented unprecedented challenges for blood services throughout the world. This study aims to understand the motivating factors that drive WB and CCP donations in the context of the pandemic. This cross-sectional study is based on data extracted from surveys of the two volunteer donor cohorts. The findings reveal that when compared to CCP donors, WB donors were more likely to view donation as a form of social engagement (97.7% vs. 87.1%, p < 0.01), advantageous in the workplace (46.4% vs. 28.6%, p < 0.01), advantageous in their social network (58.6% vs. 47.0%, p = 0.01), and view their donation in the context of positive self-satisfaction (99% vs. 95.1%, p = 0.01). The average age of CCP donors was 7.1 years younger than those who donated WB (p < 0.01). Motivational factors were also analyzed by sex and religiosity. In conclusion, whereas both donor groups showed a high motivation to partake in these life-saving commitments, WB donors were more likely to be motivated by factors that, when better-understood and implemented in policies concerning plasma donations, may help to increase these donations.

Double-blinded, randomised, placebo-controlled trial of convalescent plasma for COVID-19: analyses by neutralising antibodies homologous to recipients' variants.

INTRODUCTION: Convalescent plasma (CP) emerged as potential treatment for COVID-19 early in the pandemic. While efficacy in hospitalised patients has been lacklustre, CP may be beneficial at the first stages of disease. Despite multiple new variants emerging, no trials have involved analyses on variant-specific antibody titres of CP. METHODS: We recruited hospitalised COVID-19 patients within 10 days of symptom onset and, employing a double-blinded approach, randomised them to receive 200 ml convalescent plasma with high (HCP) or low (LCP) neutralising antibody (NAb) titre against the ancestral strain (Wuhan-like variant) or placebo in 1:1:1 ratio. Primary endpoints comprised intubation, corticosteroids for symptom aggravation, and safety assessed as serious adverse events. For a preplanned ad hoc analysis, the patients were regrouped by infused CP's NAb titers to variants infecting the recipients i.e. by titres of homologous HCP (hHCP) or LCP (hLCP). RESULTS: Of the 57 patients, 18 received HCP, 19 LCP and 20 placebo, all groups smaller than planned. No significant differences were found for primary endpoints. In ad hoc analysis, hHCPrecipients needed significantly less respiratory support, and appeared to be given corticosteroids less frequently (1/14; 7.1%) than those receiving hLCP (9/23; 39.1%) or placebo (8/20; 40%), (p = 0.077). DISCUSSION: Our double-blinded, placebo-controlled CP therapy trial remained underpowered and does not allow any firm conclusions for early-stage hospitalised COVID-19 patients. Interestingly, however, regrouping by homologous - recipients' variant-specific - CP titres suggested benefits for hHCP. We encourage similar re-analysis of ongoing/previous larger CP studies. TRIAL REGISTRATION: ClinTrials.gov identifier: NCT0473040.

SARS-CoV-2 Persistence in Immunocompromised Patients Requiring Treatment With Convalescent Plasma: A Case Report.

Severe acute respiratory syndrome-2 (SARS-CoV-2) infection in immunocompromised patients presents a challenge, as patients with such conditions may have severe courses. Identifying modalities to shorten the course or lessen the severity of infection could be potentially beneficial. A 76-year-old male with follicular lymphoma on rituximab and lenalidomide presented with COVID-19 pneumonia requiring intensive care unit (ICU) level care for persistent hypoxemia. He was treated with an extended course of remdesivir, as recommended by the Infectious Diseases service, but he maintained a persistently high viral load, necessitating a delay of his cancer treatment until he had recovered from his infection. On hospital day 31, he was given one dose of convalescent plasma with improvement in his SARS-CoV-2 viral load. He was able to be discharged and resumed cancer treatment soon thereafter. Convalescent plasma is a potential therapeutic option for immunocompromised patients with SARS-CoV-2 infection and should be considered early in the hospital course. Additionally, cycle threshold monitoring may be beneficial in certain scenarios: for instance to guide consideration of alternative therapies in patients with severe COVID-19 who have persistent symptoms and viremia while on guideline-directed therapy.

Safety and Efficacy of Convalescent Plasma Combined with Other Pharmaceutical Agents for Treatment of COVID-19 in Hospitalized Patients: A Systematic Review and Meta-Analysis.

Plasma collected from people recovered from COVID-19 (COVID-19 convalescent plasma, CCP) was the first antibody-based therapy employed to fight the pandemic. CCP was, however, often employed in combination with other drugs, such as the antiviral remdesivir and glucocorticoids. The possible effect of such interaction has never been investigated systematically. To assess the safety and efficacy of CCP combined with other agents for treatment of patients hospitalized for COVID-19, a systematic literature search using appropriate Medical Subject Heading (MeSH) terms was performed through PubMed, EMBASE, Cochrane central, medRxiv and bioRxiv. The main outcomes considered were mortality and safety of CCP combined with other treatments versus CCP alone. This review was carried out in accordance with Cochrane methodology including risk of bias assessment and grading of the quality of evidence. Measure of treatment effect was the risk ratio (RR) together with 95% confidence intervals (CIs). A total of 11 studies (8 randomized controlled trials [RCTs] and 3 observational) were included in the systematic review, 4 studies with CCP combined with remdesivir and 6 studies with CCP combined with corticosteroids, all involving hospitalized patients. One RCT reported information on both remdesivir and steroids use with CCP. The use of CCP combined with remdesivir was associated with a significantly reduced risk of death (RR 0.74; 95% CI 0.56-0.97; p = 0.03; moderate certainty of evidence), while the use of steroids with CCP did not modify the mortality risk (RR 0.72; 95% CI 0.34-1.51; p = 0.38; very low certainty of evidence). Not enough safety data were retrieved form the systematic literature analysis. The current evidence from the literature suggests a potential beneficial effect on mortality of combined CCP plus remdesivir compared to CCP alone in hospitalized COVID-19 patients. No significant clinical interaction was found between CCP and steroids.

Convalescent Plasma Therapy in Immunocompromised Patients Infected With the BA.1 or BA.2 Omicron SARS-CoV-2.

The emergence of SARS-CoV-2 Omicron variant has led to a complete reconfiguration of the therapeutic landscape, with all monoclonal antibodies having lost any neutralization activity. We report here a case series of 75 immunocompromised patients infected by the Omicron variant who benefited from COVID-19 convalescent plasma (CCP). At Day 28, the overall survival was 76% (95% CI 67-86) with no significant difference in the clinical outcome between patients with hematological malignancies, solid organ transplantation or autoimmune diseases. No safety concern was reported during the course of the study. These results showed that CCP is well tolerated and represents a treatment option for immunocompromised patients who remain highly impacted by the COVID19 epidemic.

Charting a path forward: Promising outcomes of convalescent plasma therapy in the care of severely B-cell depleted patients with persistent COVID-19.

BACKGROUND: Patients with severe B-cell depletion related to hematological malignancies or B-cell targeted therapy suffer from impaired antibody responses to SARS-CoV-2 and are at risk for prolonged COVID-19. In this population, COVID-19 convalescent plasma (CCP) may provide passive immunity, enhance immune response, and promote virus neutralization. This study evaluated outcomes of B-cell depleted patients with persistent COVID-19 treated with CCP. STUDY DESIGN AND METHODS: This analysis included all consecutive severely B-cell depleted patients with persistent COVID-19, receiving CCP at Rambam between 01.2022-02.2023. Persistent COVID-19 was defined as the presence of symptoms for ≥14 days in patients with negative SARS-CoV-2 nucleocapsid antibody test results. RESULTS: Twenty patients met inclusion criteria, 17 of whom had hematological malignancies, two suffered from rheumatoid arthritis and one had both. Twelve patients received anti-CD-20 treatment, one - CAR-T cells and three underwent stem cell transplantation. The median duration of COVID-19 symptoms was 27.5 days (range 14-97); 12 patients had mild-to-moderate COVID-19 and 8 had severe infection. Sixteen patients required hospitalization. The majority of patients received other COVID-19 therapies before CCP. Within a median of two days (range 1-16) post-infusion, 19/20 patients clinically improved. No CCP-associated adverse events were documented. COVID-19 symptoms recurred in 3 of the improved patients. Two patients died from COVID-19 on days 1 and 90 following the first CCP infusion. DISCUSSION: In severely B-cell depleted patients with persistent COVID-19, CCP is safe and associated with rapid clinical improvement. This subset of immunocompromised patients could particularly benefit from CCP administration.

Hyperimmune Plasma and Immunoglobulins against COVID-19: A Narrative Review.

Since late 2019, the new SARS-CoV-2 virus belonging to the Coronaviridae family has been responsible for COVID-19 pandemic, a severe acute respiratory syndrome. Several antiviral therapies, mostly derived from previous epidemics, were initially repurposed to fight this not rarely life-threatening respiratory illness. Among them, however, the only specific antibody-based therapy available against SARS-CoV-2 infection during the first year of the pandemic was represented by COVID-19 convalescent plasma (CCP). CCP, collected from recovered individuals, contains high levels of polyclonal antibodies of different subclasses able to neutralize SARS-CoV-2 infection. Tens of randomized controlled trials have been conducted during the last three years of the pandemic to evaluate the safety and the clinical efficacy of CCP in both hospitalized and ambulatory COVID-19 patients, whose main results will be summarized in this narrative review. In addition, we will present the current knowledge on the development of anti-SARS-CoV-2 hyperimmune polyclonal immunoglobulins.

A Descriptive, Retrospective Analysis of COVID-19 Passive Antibody Therapy and Its Effects on Morbidity and Mortality in Patients Receiving B-Cell-Depleting Therapies.

Patients receiving B-cell-depleting therapies (BCDT) are at an increased risk for severe COVID-19. Passive antibody therapy (PAT), including COVID-19 convalescent plasma (CCP) and monoclonal antibodies (mAb), may be an effective treatment in this population. Real-world data on PAT effectiveness are limited. To evaluate response to PAT measured through 90-day all-cause morbidity and mortality, we performed a retrospective review of patients who contracted COVID-19 within a year from the last BCDT. From 64 included patients, the majority were Caucasians (95%), female (56%), vaccinated (67%), treated outpatients (64%), with multiple comorbidities. Examined BCDT were rituximab (55%), obinutuzumab (33%), ocrelizumab (11%) and ofatumumab (1%), used for underlying hematological malignancy (HEM) (40%), multiple sclerosis (34%), and rheumatoid arthritis (16%). Of seven deceased patients, three died from COVID-19. All three were elderly males with multiple comorbidities, treated inpatient for severe COVID-19. Four of 41 patients treated as outpatients were hospitalized for non-COVID-19-related reasons. All deceased and hospitalized patients had an underlying HEM. All but one were on rituximab. PAT may be an effective treatment for patients receiving BCDT, especially if given early for non-severe disease. Patients with underlying HEM may be at increased risk for severe disease compared with others receiving the same BCDT.

Experience report of two living systematic Cochrane reviews on COVID-19.

INTRODUCTION: Up-to-date systematic reviews (SRs) are essential for making evidence-based decisions. During the 2019 coronavirus (COVID-19) pandemic, there was a particular need for up-to-date evidence, making the living systematic review (LSR) approach an appropriate review type. However, this approach poses certain challenges. OBJECTIVE AND OUTLINE: We aim to provide practice insights and report challenges that we faced while conducting two Cochrane LSRs on COVID-19 treatments with (i) convalescent plasma and (ii) systemic corticosteroids. We address our objective with an experience report and share challenges of the following components based on Iannizzi et al. (2022): study design, publication types, intervention/comparator, outcomes, search strategy, review updates and transparent reporting of differences between review updates. RESULTS: Regarding the study design, the plasma LSR included different study designs because RCT data were not available at the beginning of the pandemic, whereas for the corticosteroids LSR, which started several months later, RCT data were already available. The challenges in both LSRs included the publication types (preprints were included with caution) and the intervention/comparator, for instance the unavailability of standard of care for either LSR, or SARS-CoV-2 variants occurrence. Further challenges in both LSRs occurred in the components "outcome sets" (which had to be adjusted) and "literature search". The decision criteria for updating were based on important studies and available resources in both LSRs and policy relevance in the plasma LSR. Transparent reporting of the differences between the various update versions were discussed for both LSRs. DISCUSSION AND CONCLUSION: In summary, there are similarities and differences regarding challenges of review components for both LSRs. It is important to keep in mind that the two LSR examples presented here were conducted in the wake of the COVID-19 pandemic. Therefore, many of the challenges are attributable to the pandemic and are not specific to LSRs, such as constant adjustments of the outcome sets or changes in the database search. Nevertheless, we believe that some of these aspects are helpful for LSR authors and are applicable to other LSRs outside the pandemic context, particularly in areas where new evidence is rapidly emerging.

COVID-19 Convalescent Plasma Therapy: Long-term Implications.

Background: The long-term effect of coronavirus disease 2019 (COVID-19) acute treatments on postacute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (PASC) is unknown. The CONTAIN-Extend study explores the long-term impact of COVID-19 convalescent plasma (CCP) therapy on postacute sequelae of SARS-CoV-2 infection (PASC) symptoms and general health 18 months following hospitalization. Methods: The CONTAIN-Extend study examined 281 participants from the original CONTAIN COVID-19 trial (CONTAIN-RCT, NCT04364737) at 18 months post-hospitalization for acute COVID-19. Symptom surveys, global health assessments, and biospecimen collection were performed from November 2021 to October 2022. Multivariable logistic and linear regression estimated associations between the randomization arms and self-reported symptoms and Patient-Reported Outcomes Measurement Information System (PROMIS) scores and adjusted for covariables, including age, sex, race/ethnicity, disease severity, and CONTAIN enrollment quarter and sites. Results: There were no differences in symptoms or PROMIS scores between CCP and placebo (adjusted odds ratio [aOR] of general symptoms, 0.95; 95% CI, 0.54-1.67). However, females (aOR, 3.01; 95% CI, 1.73-5.34), those 45-64 years (aOR, 2.55; 95% CI, 1.14-6.23), and April-June 2020 enrollees (aOR, 2.39; 95% CI, 1.10-5.19) were more likely to report general symptoms and have poorer PROMIS physical health scores than their respective reference groups. Hispanic participants (difference, -3.05; 95% CI, -5.82 to -0.27) and Black participants (-4.48; 95% CI, -7.94 to -1.02) had poorer PROMIS physical health than White participants. Conclusions: CCP demonstrated no lasting effect on PASC symptoms or overall health in comparison to the placebo. This study underscores the significance of demographic factors, including sex, age, and timing of acute infection, in influencing symptom reporting 18 months after acute hypoxic COVID-19 hospitalization.

The Effect of COVID Convalescent Plasma on Hospital Stay: A Retrospective Observational Study from a Tertiary Care Hospital in North India.

INTRODUCTION: COVID convalescent plasma (CCP) has been used as standard of care in patients all over the world. CCP is plasma collected from recently infected and currently recovered COVID-19 patients, which contains antiviral antibodies that can be used to treat patients with COVID-19. Several studies have shown a shorter hospital stay and lower mortality in patients treated with convalescent plasma in comparison with those not treated with it. OBJECTIVES: This study aims to determine the effect of COVID convalescent plasma (CCP) on the length of hospital stay in symptomatic patients and to determine outcome of the disease in patients who were administered CCP. METHODS: This was a retrospective observational study done at a tertiary health care centre from July 2020 to May 2021, including patients who received CCP during the course of their stay in the hospital. RESULTS: Among 257 participants, the patients with multiple comorbidities who were administered CCP had the longest average length of stay in the hospital which was 15 days, out of which, 92 (35.8%) patients were discharged while 9 (3.5%) patients died. Also, the maximum number of deaths was observed in those patients who had no associated comorbidity, being 11 (4.3%). It was observed that earlier administration of CCP in patients (< 5 days from symptom onset) was associated with a higher number of discharges as compared to deaths. CONCLUSION: Our study indicates that CCP may be efficient in treating COVID-19 patients if given in early course of the disease.

Factors related to the development of high antibody titres against SARS-CoV-2 in convalescent plasma donors from the ConPlas-19 trial.

BACKGROUND AND OBJECTIVES: The efficacy of COVID-19 convalescent plasma (CP) associates with high titres of antibodies. ConPlas-19 clinical trial showed that CP reduces the risk of progression to severe COVID-19 at 28 days. Here, we aim to study ConPlas-19 donors and characteristics that associate with high anti-SARS-CoV-2 antibody levels. MATERIALS AND METHODS: Four-hundred donors were enrolled in ConPlas-19. The presence and titres of anti-SARS-CoV-2 antibodies were evaluated by EUROIMMUN anti-SARS-CoV-2 S1 IgG ELISA. RESULTS: A majority of 80.3% of ConPlas-19 donor candidates had positive EUROIMMUN test results (ratio ≥1.1), and of these, 51.4% had high antibody titres (ratio ≥3.5). Antibody levels decline over time, but nevertheless, out of 37 donors tested for an intended second CP donation, over 90% were still EUROIMMUN positive, and nearly 75% of those with high titres maintained high titres in the second sample. Donors with a greater probability of developing high titres of anti-SARS-CoV-2 antibodies include those older than 40 years of age (RR 2.06; 95% CI 1.24-3.42), with more than 7 days of COVID-19 symptoms (RR 1.89; 95% CI 1.05-3.43) and collected within 4 months from infection (RR 2.61; 95% CI 1.16-5.90). Male donors had a trend towards higher titres compared with women (RR 1.67; 95% CI 0.91-3.06). CONCLUSION: SARS-CoV-2 CP candidate donors' age, duration of COVID-19 symptoms and time from infection to donation associate with the collection of CP with high antibody levels. Beyond COVID-19, these data are relevant to inform decisions to optimize the CP donor selection process in potential future outbreaks.

COVID-19 convalescent plasma therapy decreases inflammatory cytokines: a randomized controlled trial.

IMPORTANCE: This study examined the role that cytokines may have played in the beneficial outcomes found when outpatient individuals infected with SARS-CoV-2 were transfused with COVID-19 convalescent plasma (CCP) early in their infection. We found that the pro-inflammatory cytokine IL-6 decreased significantly faster in patients treated early with CCP. Participants with COVID-19 treated with CCP later in the infection did not have the same effect. This decrease in IL-6 levels after early CCP treatment suggests a possible role of inflammation in COVID-19 progression. The evidence of IL-6 involvement brings insight into the possible mechanisms involved in CCP treatment mitigating SARS-CoV-2 severity.

Treatments for COVID-19.

The treatment for COVID-19 has evolved rapidly since the start of the pandemic and now consists mainly of antiviral and immunomodulatory agents. Antivirals, such as remdesivir and nirmatrelvir-ritonavir, have proved to be most useful earlier in illness (e.g., as outpatient therapy) and for less severe disease. Immunomodulatory therapies, such as dexamethasone and interleukin-6 or Janus kinase inhibitors, are most useful in severe disease or critical illness. The role of anti-SARS-CoV-2 monoclonal antibodies has diminished because of the emergence of viral variants that are not anticipated to be susceptible to these treatments, and there still is not a consensus on the use of convalescent plasma. COVID-19 has been associated with increased rates of venous thromboembolism, but the role of antithrombotic therapy is limited. Multiple investigational agents continue to be studied, which will alter current treatment paradigms as new data are released.

Passive antibody therapy in emerging infectious diseases.

The epidemic of corona virus disease 2019 (COVID-19) caused by severe acute respiratory syndrome Coronavirus 2 and its variants of concern (VOCs) has been ongoing for over 3 years. Antibody therapies encompassing convalescent plasma, hyperimmunoglobulin, and neutralizing monoclonal antibodies (mAbs) applied in passive immunotherapy have yielded positive outcomes and played a crucial role in the early COVID-19 treatment. In this review, the development path, action mechanism, clinical research results, challenges, and safety profile associated with the use of COVID-19 convalescent plasma, hyperimmunoglobulin, and mAbs were summarized. In addition, the prospects of applying antibody therapy against VOCs was assessed, offering insights into the coping strategies for facing new infectious disease outbreaks.