Serum anti-Spike immunoglobulin G levels in random blood donors in Italy: High-titre convalescent plasma is easier than ever to procure

Fresh frozen plasma for neutralizing SARS-CoV-2: "An exploratory cross-sectional study and review of the state of the art"

Restitution of humoral immunodeficiency is essential to clear SARS-CoV-2. Intravenous unspecific immunoglobulins are expensive and restricted. So recently donated fresh frozen plasma (FFP) could be useful in this scenario but, are all units neutralizing against SARS-CoV-2? We explored this on 52 donations obtained from "Centro de Transfusión, Tejidos y Células de Málaga, Spain", from April to June 2022. Donors status about SARS-CoV-2 previous infection or vaccination was unknown. Neutralizing activity (at dilutions≥1/160) against real Delta (not circulating), BA.2 (dominant circulating variant), BA.5 (irrupting variant), and BQ.1.1 and XBB.1.5 (not circulating yet) was determined. Higher anti-Spike IgG antibodies cut-offs predicted efficacy of FFP. Different cut-offs have been reported in the literature, but all papers have in common that levels over the higher range of quantification can predict neutralizing activity of recently donated FFP against circulating variants of concern, if used early after donation, not requiring clinical data from donors.

Novel approaches for preventing COVID-19 infection in immunocompromised patients with hematologic malignancies

INTRODUCTION

COVID-19 is a continuing challenge for immunocompromised patients with hematological malignancies. Such patients are at increased risk for complications, including hospitalization, respiratory failure, delayed anti-cancer therapies, and even death. In addition to non-pharmacologic interventions, the main strategies for prevention in such patients are vaccination and pre-exposure prophylaxis.

AREAS COVERED

In this narrative review, which relied on a review of the PubMed and bioRxiv databases (starting 1 November 2019), we summarize the epidemiology of COVID-19 and vaccine responses in patients with hematological malignancies and the use of antiviral agents as prophylaxis. A limitation to vaccination is suboptimal immune responses in immunocompromised patients, particularly those with abnormalities in lymphocyte count and function. A limitation to prophylaxis, which has only been proven effective for antiviral monoclonal antibodies (mAbs), is the emergence of resistant strains in the general population.

EXPERT OPINION

For immunocompromised patients with hematological malignancies, we recommend vaccinations as guided by evolving US Centers for Disease Control and Prevention (CDC) recommendations, consideration of pre-exposure prophylaxis with antiviral mAbs, providing that they are effective against circulating viral strains, and rapid diagnostic testing linked to early therapy for the prevention of severe complications of COVID-19 in those who have broken through the prevention strategies.

Outpatient treatment with concomitant vaccine-boosted convalescent plasma for patients with immunosuppression and COVID-19

Although severe coronavirus disease 2019 (COVID-19) and hospitalization associated with COVID-19 are generally preventable among healthy vaccine recipients, patients with immunosuppression have poor immunogenic responses to COVID-19 vaccines and remain at high risk of infection with SARS-CoV-2 and hospitalization. In addition, monoclonal antibody therapy is limited by the emergence of novel SARS-CoV-2 variants that have serially escaped neutralization. In this context, there is interest in understanding the clinical benefit associated with COVID-19 convalescent plasma collected from persons who have been both naturally infected with SARS-CoV-2 and vaccinated against SARS-CoV-2 ("vax-plasma"). Thus, we report the clinical outcome of 386 immunocompromised outpatients who were diagnosed with COVID-19 and who received contemporary COVID-19-specific therapeutics (standard-of-care group) and a subgroup who also received concomitant treatment with very high titer COVID-19 convalescent plasma (vax-plasma group) with a specific focus on hospitalization rates. The overall hospitalization rate was 2.2% (5 of 225 patients) in the vax-plasma group and 6.2% (10 of 161 patients) in the standard-of-care group, which corresponded to a relative risk reduction of 65% (P = 0.046). Evidence of efficacy in nonvaccinated patients cannot be inferred from these data because 94% (361 of 386 patients) of patients were vaccinated. In vaccinated patients with immunosuppression and COVID-19, the addition of vax-plasma or very high titer COVID-19 convalescent plasma to COVID-19-specific therapies reduced the risk of disease progression leading to hospitalization.IMPORTANCEAs SARS-CoV-2 evolves, new variants of concern (VOCs) have emerged that evade available anti-spike monoclonal antibodies, particularly among immunosuppressed patients. However, high-titer COVID-19 convalescent plasma continues to be effective against VOCs because of its broad-spectrum immunomodulatory properties. Thus, we report clinical outcomes of 386 immunocompromised outpatients who were treated with COVID-19-specific therapeutics and a subgroup also treated with vaccine-boosted convalescent plasma. We found that the administration of vaccine-boosted convalescent plasma was associated with a significantly decreased incidence of hospitalization among immunocompromised COVID-19 outpatients. Our data add to the contemporary data providing evidence to support the clinical utility of high-titer convalescent plasma as antibody replacement therapy in immunocompromised patients.

The Role of Convalescent Plasma in COVID-19: A Conclusive Post-Pandemic Review

COVID-19 convalescent plasma (CCP) has represented the frontline response to the COVID-19 pandemic, largely because of encouraging historical evidences in previous pandemics, biological plausibility, and the initial unavailability of targeted antivirals. Unfortunately, investigator-initiated randomized clinical trials in 2020, launched during a stressful pandemic peak, were designed mostly at addressing the main unmet need, i.e., treating critically ill hospitalized patients who were unlikely to benefit from any antiviral therapy. The failure of most of these drugs, in combination with the lack of any sponsor, led to the false belief that convalescent plasma was useless. With the relaxing pandemic stages, evidences have instead mounted that, when administered properly (i.e., within 5 days from onset of symptoms and at high titers of neutralizing antibodies), CCP is as effective as other antivirals at preventing disease progression in outpatients, and also reduces mortality in hospitalized patients. Recently, the focus of clinical use has been on immunosuppressed patients with persistent seronegativity and infection, where a randomized clinical trial has shown a reduction in mortality. Lessons learnt during the COVID-19 pandemic will be of utmost importance for future pandemics.