A Randomized Controlled Study Assessing Convalescent Immunoglobulins vs Convalescent Plasma for Hospitalized Patients With Coronavirus 2019

Persistent COVID-19 in immunocompromised patients-Israeli society of infectious diseases consensus statement on diagnosis and management

BACKGROUND

Immunocompromised patients with impaired humoral immunity are at risk for persistent COVID-19 (pCOVID), a protracted symptomatic disease with active viral replication.

OBJECTIVES

To establish a national consensus statement on the diagnosis, treatment, management, isolation, and prevention of pCOVID in adults.

SOURCES

We base our suggestions on the available literature, our own experience, and clinical reasoning.

CONTENT

Literature on the treatment of pCOVID is scarce and consists of few case reports and case series. The available studies provide low-quality evidence for monoclonal antibodies, convalescent plasma, antiviral drugs, and immunomodulators. Different combination therapies are described. Continuous viral replication and antiviral treatment may lead to the development of mutations that confer resistance to therapy.

IMPLICATIONS

To reduce the risk of resistance and improve outcomes, we suggest treating pCOVID with a combination of antibody-based therapy and two antiviral drugs for duration of 5-10 days. Immunomodulatory therapy can be added in patients with an inflammatory clinical picture. In cases of treatment failure or relapse, prolonged antiviral treatment can be considered. For the prevention of pCOVID, we suggest active and passive vaccination and early initiation of treatment for acute COVID-19. Additional research on pCOVID treatment is urgently needed.

Effect of intravenous immunoglobulin on mortality in hospitalized patients with COVID-19: A systematic review and meta-analysis of randomized controlled trials

Background and Aims

We performed a meta-analysis of randomized controlled trials (RCTs) to summarize the overall effect of intravenous immunoglobulin (IVIG) on mortality outcomes among hospitalized coronavirus disease 2019 (COVID-19) patients.

Methods

We systematically searched electronic databases up to June 1, 2023. Pooled odds ratio (OR) of mortality with a 95% confidence interval (CI) was generated using a random-effects model. The risk of bias was appraised using the Cochrane risk-of-bias Version 2 tool for randomized trials.

Results

Nine RCTs were included: three RCTs had an overall low risk of bias, four RCTs had some concerns in the overall risk of bias, and two RCTs trials had an overall high risk of bias. The use of IVIG indicated a significant reduction in the odds of mortality (pooled OR = 0.69; 95% CI 0.50-0.96) relative to nonuse of IVIG. Subgroup analysis in patients with a severe course of COVID-19 revealed no significant reduction in the odds of mortality (pooled OR = 0.58; 95% CI 0.29-1.16).

Conclusions

We suggest exercising caution when interpreting effectiveness of IVIG in reducing mortality among hospitalized patients with COVID-19. Our findings emphasize for larger trials with rigorous study designs to better understand the impact of IVIG, particularly in those with severe COVID-19.

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.

COVID-19 therapeutics

SUMMARYSince the emergence of COVID-19 in 2020, an unprecedented range of therapeutic options has been studied and deployed. Healthcare providers have multiple treatment approaches to choose from, but efficacy of those approaches often remains controversial or compromised by viral evolution. Uncertainties still persist regarding the best therapies for high-risk patients, and the drug pipeline is suffering fatigue and shortage of funding. In this article, we review the antiviral activity, mechanism of action, pharmacokinetics, and safety of COVID-19 antiviral therapies. Additionally, we summarize the evidence from randomized controlled trials on efficacy and safety of the various COVID-19 antivirals and discuss unmet needs which should be addressed.

From Detection to Protection: Antibodies and Their Crucial Role in Diagnosing and Combatting SARS-CoV-2

Understanding the antibody response to SARS-CoV-2, the virus responsible for COVID-19, is crucial to comprehending disease progression and the significance of vaccine and therapeutic development. The emergence of highly contagious variants poses a significant challenge to humoral immunity, underscoring the necessity of grasping the intricacies of specific antibodies. This review emphasizes the pivotal role of antibodies in shaping immune responses and their implications for diagnosing, preventing, and treating SARS-CoV-2 infection. It delves into the kinetics and characteristics of the antibody response to SARS-CoV-2 and explores current antibody-based diagnostics, discussing their strengths, clinical utility, and limitations. Furthermore, we underscore the therapeutic potential of SARS-CoV-2-specific antibodies, discussing various antibody-based therapies such as monoclonal antibodies, polyclonal antibodies, anti-cytokines, convalescent plasma, and hyperimmunoglobulin-based therapies. Moreover, we offer insights into antibody responses to SARS-CoV-2 vaccines, emphasizing the significance of neutralizing antibodies in order to confer immunity to SARS-CoV-2, along with emerging variants of concern (VOCs) and circulating Omicron subvariants. We also highlight challenges in the field, such as the risks of antibody-dependent enhancement (ADE) for SARS-CoV-2 antibodies, and shed light on the challenges associated with the original antigenic sin (OAS) effect and long COVID. Overall, this review intends to provide valuable insights, which are crucial to advancing sensitive diagnostic tools, identifying efficient antibody-based therapeutics, and developing effective vaccines to combat the evolving threat of SARS-CoV-2 variants on a global scale.

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.

Comparison of SARS-CoV-2 Hyperimmune Immunoglobulins Following Infection Plus Vaccination vs Infection

This cross-sectional study compares the neutralizing titers of convalescent plasma and hyperimmune anti–SARS-CoV-2 intravenous immunoglobulins against circulating Omicron subvariants.