Nevertheless, the pandemic has not ceased, and it seems there is still much to do to control it.ĭespite the large number of investigations carried out so far, COVID-19 disease mechanism/pathophysiology is largely unknown. To reduce the progress of the pandemic, the WHO has recommended precautionary measures, such as the use of masks, hand washing, social distancing, and lockdowns. By the end of November 2021, more than 257 million cases, with more than 5.1 million deaths, had been reported worldwide. Severe cases are more frequent in elderly patients with comorbidities, such as high blood pressure, heart and lung diseases, diabetes, and cancer ( 3).Īfter the first cases reported in Wuhan, COVID-19 spread rapidly throughout the world, acquiring the status of pandemic, declared by the World Health Organization (WHO), in March 2020. Signs and symptoms of COVID-19 range from mild/moderate (dry cough, fever, tiredness, chills, sore throat, loss of smell and taste, headache, body pain, nasal congestion, diarrhea, nausea, and vomiting) to severe (thrombosis, cardiac damage, and massive alveolar damage, respiratory failure, and death) ( 3). Occasionally, however, after an incubation period of 2–14 days, patients develop the coronavirus disease 2019 (COVID-19) ( 3). In most cases, infection by SARS-CoV-2 is asymptomatic. The virion infects human cells, as well as some other mammalian and avian cells, through the interaction between RBD and the angiotensin-converting enzyme 2 (ACE2) ( 1).

Each S protein monomer consists of S1 and S2 subunits, and possesses several functional domains ( 1), including the receptor binding domain (RBD) located in the S1 subunit ( 2). SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) is an enveloped, positive sense RNA virus, composed of four structural proteins: envelope (E), membrane (M), nucleocapsid (N), and the homotrimeric spike (S) protein.

Precipitation with caprylic acid could be a simple, feasible, and affordable alternative to produce formulations of anti-SARS-CoV-2 IVIg to be used therapeutically or prophylactically to confront the COVID-19 pandemic in middle and low-income countries. Thus, VP-IVIg has in vitro efficacy and safety profiles that justify their evaluation as therapeutic alternative for clinical cases of COVID-19. In concordance, plaque reduction neutralization tests showed inhibitory concentrations of 0.03–0.09 g/L in VP-IVIg and of 0.06–0.13 in CP-IVIg. Moreover, the concentration of anti-RBD and ACE2-RBD neutralizing antibodies was higher in VP-IVIg than in CP-IVIg. Both formulations showed immunological, physicochemical, biochemical, and microbiological characteristics that meet the specifications of IVIg formulations. We used caprylic acid precipitation to prepare a pilot-scale batch of anti-SARS-CoV-2 intravenous immunoglobulins (IVIg) from plasma of donors immunized with the BNT162b2 (Pfizer-BioNTech) anti-COVID-19 vaccine (VP-IVIg) and compared their in vitro efficacy and safety with those of a similar formulation produced from plasma of COVID-19 convalescent donors (CP-IVIg).

In these cases, as well as in patients with moderate/severe COVID-19, passive immunization with anti-SARS-CoV-2 immunoglobulins could be a therapeutic alternative. Despite vaccines are the main strategy to control the ongoing global COVID-19 pandemic, their effectiveness could not be enough for individuals with immunosuppression.

Residual claimant