Demographic and Clinical Factors Associated with Reactivity of Anti-SARS-CoV-2 Antibodies in Serbian Convalescent Plasma Donors

Passive immunotherapy with convalescent COVID-19 plasma (CCP) is used as a therapeutic procedure in many countries, including Serbia. In this study, we analyzed the association between demographic factors, COVID-19 severity and the reactivity of anti-SARS-CoV-2 antibodies (Abs) in Serbian CCP donors. Individuals (n = 468) recovered from confirmed SARS-CoV-2 infection, and who were willing to donate their plasma for passive immunization of COVID-19 patients were enrolled in the study. Plasma samples were tested for the presence of IgG reactive to SARS-CoV-2 spike glycoprotein (S1) and nucleocapsid antigens. Individuals were characterized according to age, gender, comorbidities, COVID-19 severity, ABO blood type and RhD factor. Total of 420 candidates (420/468; 89.74%) reached the levels of anti-SARS-CoV-2 IgG that qualified them for inclusion in CCP donation program. Further statistical analysis showed that male individuals (p = 0.034), older age groups (p < 0.001), existence of hypertension (p = 0.008), and severe COVID-19 (p = 0.000) are linked with higher levels of anti-SARS-CoV-2 Abs. These findings will guide the selection of CCP donors in Serbia. Further studies need to be conducted to assess the neutralization potency and clinical efficiency of CCP collected from Serbian donors with high anti-SARS-CoV-2 IgG reactivity.

Vaccination of COVID-19 Convalescent Plasma Donors Increases Binding and Neutralizing Antibodies Against SARS-CoV-2 Variants

Background: COVID-19 convalescent plasma (CCP) was widely used as passive immunotherapy during the first waves of SARS-CoV-2 infection in the US. However, based on observational studies and randomized controlled trials, beneficial effects of CCP were limited, and its use was virtually discontinued early in 2021, in concurrence with increased vaccination rates and availability of monoclonal antibody (mAb) therapeutics. However, as new variants of the SARS-CoV-2 spread, interest in CCP derived from vaccine-boosted CCP donors is resurging. The effect of vaccination of previously infected CCP donors on antibodies against rapidly spreading variants of concern (VOC) is still under investigation. Study Design/Methods: In this study, paired samples from 11 CCP donors collected before and after vaccination were tested to measure binding antibodies levels and neutralization activity against the ancestral and SARS-CoV-2 variants (Wuhan-Hu-1, B.1.1.7, B.1.351, P.1, D614G, B.1.617.2, B.1.427) on the Ortho Vitros Spike Total Ig and IgG assays, the MSD V-PLEX SARS-CoV-2 Panel 6 arrays for IgG binding and ACE2 inhibition, and variant-specific Spike Reporter Viral Particle Neutralization (RVPN) assays. Results/Findings: Binding and neutralizing antibodies were significantly boosted by vaccination, with several logs higher neutralization for all the variants tested post-vaccination compared to the pre-vaccination samples, with no difference found among the individual variants. Discussion: Vaccination of previously infected individuals boosts antibodies including neutralizing activity against all SARS-CoV-2 VOC, including the current spreading delta (B.1.617.2) variant. Animal model and human studies to assess clinical efficacy of vaccine boosted CCP are warranted, especially since 15-20% of current donations in the US are from previously infected vaccine-boosted donors.

Gain of Function Research: the Clairvoyant Lens on Pandemics

Pandemic influenza viruses have emerged three times in this century. It is important to examine the potential risk of novel microorganisms/viruses through the add-on research mechanism of Gain of Function Research (GoFR). This mechanism consists of the practice of serial passaging of microorganisms to increase their transmissibility, virulence, immunogenicity, and host tropism through the inclusive feature of selective pressure of culture medium. Although, the GoFR can be a double-edged sword that has the potential to give an insight and better appreciation of current and future pandemics with antecedent apprehension of initiating a pandemic, itself. Moreover, with its inherent potential to give a head start on a virus, GoFR has the potential to develop vaccines or therapeutics, before the virus emerges in its true virulent form. Likewise, the GoFR studies can be vital in research on antivirals and antimicrobial agents and can help inform the development of combination therapies. Passive immunotherapy, which often includes a combination of products, is particularly dependent on GoFR experiments for evaluating efficacy. GoFR if made use of meticulously and with caution could help Medical Sciences and Humankind tremendously.

Antibody therapy against antibiotic-resistant diarrheagenic Escherichia coli: a systematic review

Over four billion episodes of diarrhea occur annually in developing countries with diarrheagenic Escherichia coli (DEC) outbreaks also being reported, until now bacterial diarrhea is conventionally addressed by the antibiotic treatment regimes. In recent decades, the emergence of antimicrobial-resistant strains has become a major obstacle in diarrheal treatment; hence, novel and ideal therapeutics are needed. Notably, 80% of DEC is resistant to first-class antibiotics. Among the existing strategies, passive immunization is considered as an alternative to combat drug-resistant bacteria. Antibodies specific to an antigen can be used for prophylactic and therapeutic purposes. In this review, we have systematically discussed the effect of passive immunotherapy to combat DEC and explored the types and advancements in antibodies used against antibiotic-resistant DEC.

Donkey-derived anti-CDV IgG, as a passive immunotherapy agent, can effectively increase survival rates of the experimental CDV-infected dogs

Background Humoral immunity plays an important role in the prevention of canine distemper. Anti-CD virus (CDV) antibody has strong antiviral activity and is widely used in the treatment of CD. However, with the increase of CD cases, the availability of therapeutic CD antibody fell short of the clinical needs. Results The high-titer antiserum with the high-titer neutralizing activity against CDV was obtained from the donkeys (Dezhou Donkey) immunized with the inactivated CDV vaccine. The donkey anti-CDV IgG was purified from the donkey serum, which was identified to significantly inhibit the CDV replication in the cultured Vero cells and effectively reduce the clinical symptoms and increase the survival rates (75%) of CDV-infected dogs (Shih-tzu Dog), similar to that treated with the dog-derived anti-CDV IgG. These results indicate that donkey-derived IgG is a potential substitute for dog-derived IgG to treat the CD in clinic. Conclusions Administration of donkey-derived anti-CDV IgG can ameliorate clinical symptoms and inhibit virus replication, thereby increasing the survival of CDV-infected dogs. This study opens up a new source of therapeutic antibody for CD treatment.

Neutralizing Monoclonal Antibody: New Member of Therapeutic Armamentarium Against COVID-19

Many targeted treatment methods have focused on SARS-CoV-2's spike protein, along with neutralizing monoclonal antibodies (mAbs), which are recombinant proteins, may be employed as a kind of passive immunotherapy to reduce pathogenicity. While vaccines are still the best way to prevent COVID-19 infection, mAbs are an effective treatment for those who have already been infected, as well as having the potential to prevent infection in those who have already been exposed to SARS-CoV-2, which can be especially beneficial to certain high-risk groups. Due to the limited initial availability of these new treatments, it is essential to consider their larger potential and create methods for their optimal deployment in clinical practice. The objectives of this review is to answer the most commonly asked clinical questions from HCPs and patients about the target population, dose, interactions with other medicines and vaccines, duration of immunity, and variants.