ABSTRACT
IntroductionThe efficacy of SARS-CoV2 standard single donor convalescent plasma varied according to the application time and most importantly the amount of antibody that is administered. Single donor plasma has some drawbacks; such as the insufficient levels of neutralizing antibody activities, the requirements of blood group compatibility, and the risk of infection transmission. In this study, the efficacy and safety of pathogen inactivated, isohemagglutinin-depleted (concentrated) and pooled convalescent plasma was investigated. MethodsIn this study, ACB-IP 1.0 convalescent plasma product was prepared as follows; first, convalescent plasma was collected from different donors, then pathogen-inactivation was carried-out, and isohemagglutinins were cryodepleted, respectively. Finally, concentrated convalescent plasma product was pooled and stored until use. A total of sixteen patients were treated with two different convalescent plasma products. Nine patients were treated with standard single donor convalescent plasma and seven were treated with pathogen-free, concentrated, pooled convalescent plasma (ACB-IP 1.0) between 01 March 2020 and 31 December 2020. The outcomes of these two plasma products were compared regarding SARS-CoV2 antibody titers, neutralizing antibody activities, length of hospitalization and mortality rates. ResultsFive out of six single donor plasma SARS-CoV2 antibody titers remained below 12 s/co, but the antibody titers of all ACB-IP 1.0 plasma were above 12 s/co. SARS-CoV2 total antibody titers of ACB-IP 1.0 plasma were statistically higher than the antibody titers of single donor plasma. Mean total plasma neutralizing antibody activity of ACB-IP 1.0 plasma (1.5421) was found statistically higher than single donor plasma (0.9642) in 1:256 dilution ({rho}=0.0087) The mortality rate of the patients treated with ACB-IP 1.0 plasma showed statistically lower (p: 0,033) than the patients treated with single donor plasma. The administration of either single donor plasma or ACB-IP 1.0 plasma to the patients within eight days significantly shortened the length of hospitalization compared to administration of either plasma to the patients later than eight days ({rho}= 0,0021) DiscussionPathogen-free, concentrated, pooled convalescent plasma may resolve the bias in SARS-CoV2 antibody titers and neutralizing antibody activities, without requiring blood group compatibility that allows patient accessibility in a shorter time and has safe plasma characteristic. This study indicates that ACB-IP 1.0 may be a superior product compared to standard single donor plasma.
ABSTRACT
The SARS-CoV-2 virus caused the most severe pandemic around the world, and vaccine development for urgent use became a crucial issue. Inactivated virus formulated vaccines such as Hepatitis A, oral polio vaccine, and smallpox proved to be reliable approaches for immunization for prolonged periods. During the pandemic, we produced an inactivated SARS-CoV-2 vaccine candidate, having the advantages of being manufactured rapidly and tested easily in comparison with recombinant vaccines. In this study, an inactivated virus vaccine that includes a gamma irradiation process for the inactivation as an alternative to classical chemical inactivation methods so that there is no extra purification required has been optimized. The vaccine candidate (OZG-38.61.3) was then applied in mice by employing the intradermal route, which decreased the requirement of a higher concentration of inactivated virus for proper immunization, unlike most of the classical inactivated vaccine treatments. Hence, the novelty of our vaccine candidate (OZG-38.61.3) is that it is a non-adjuvant added, gamma-irradiated, and intradermally applied inactive viral vaccine. Efficiency and safety dose (either 1013 or 1014 viral copy per dose) of OZG-38.61.3 was initially determined in Balb/c mice. This was followed by testing the immunogenicity and protective efficacy of OZG-38.61.3. Human ACE2-encoding transgenic mice were immunized and then infected with a dose of infective SARS-CoV-2 virus for the challenge test. Findings of this study show that vaccinated mice have lower SARS-CoV-2 viral copy number in oropharyngeal specimens along with humoral and cellular immune responses against the SARS-CoV-2, including the neutralizing antibodies similar to those shown in Balb/c mice without substantial toxicity. Subsequently, plans are being made for the commencement of Phase 1 clinical trial of the OZG-38.61.3 vaccine for the COVID-19 pandemic.
ABSTRACT
COVID-19 outbreak caused by SARS-CoV-2 created an unprecedented health crisis since there is no vaccine for this novel virus. Therefore, SARS-CoV-2 vaccines have become crucial for reducing morbidity and mortality. In this study, in vitro and in vivo safety and efficacy analyzes of lyophilized vaccine candidates inactivated by gamma-irradiation were performed. The candidate vaccines in this study were OZG-3861 version 1 (V1), an inactivated SARS-CoV-2 virus vaccine, and SK-01 version 1 (V1), a GM-CSF adjuvant added vaccine. The candidate vaccines were applied intradermally to BALB/c mice to assess toxicity and immunogenicity. Preliminary results in vaccinated mice are reported in this study. Especially, the vaccine models containing GM-CSF caused significant antibody production with neutralization capacity in absence of the antibody-dependent enhancement feature, when considered in terms of T and B cell responses. Another important finding was that the presence of adjuvant was more important in T cell in comparison with B cell response. Vaccinated mice showed T cell response upon restimulation with whole inactivated SARS-CoV-2 or peptide pool. This study shows that the vaccines are effective and leads us to start the challenge test to investigate the gamma-irradiated inactivated vaccine candidates for infective SARS-CoV-2 virus in humanized ACE2+ mice.
ABSTRACT
The novel coronavirus pneumonia, which was named later as Coronavirus Disease 2019 (COVID-19), is caused by the Severe Acute Respiratory Syndrome Coronavirus 2, namely SARS-CoV-2. It is a positive-strand RNA virus that is the seventh coronavirus known to infect humans. The COVID-19 outbreak presents enormous challenges for global health behind the pandemic outbreak. The first diagnosed patient in Turkey has been reported by the Republic of Turkey Ministry of Health on March 11, 2020. Today, over ninety thousand cases in Turkey, and two million cases around the world have been declared. Due to the urgent need for vaccine and anti-viral drug, isolation of the virus is crucial. Here, we report one of the first isolation and characterization studies of SARS-CoV-2 from nasopharyngeal and oropharyngeal specimens of diagnosed patients in Turkey. This study provides an isolation and replication methodology, and cell culture tropism of the virus that will be available to the research communities. Article SummaryScientists have isolated virus from Turkish COVID-19 patients. The isolation, propagation, and plaque and immune response assays of the virus described here will serve in following drug discovery and vaccine testing.
