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

## TL;DR

This paper reviews the use of convalescent plasma and hyperimmune immunoglobulins as antibody-based therapies for treating COVID-19.

## Contribution

The paper provides a comprehensive summary of clinical trials and current knowledge on CCP and hyperimmune immunoglobulins for SARS-CoV-2.

## Key findings

- Convalescent plasma contains polyclonal antibodies that can neutralize SARS-CoV-2.
- Numerous trials evaluated the safety and efficacy of CCP in hospitalized and ambulatory patients.
- Hyperimmune polyclonal immunoglobulins are being developed as a specific therapy against SARS-CoV-2.

## Abstract

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.