A Phase II Non-Randomized Open Labelled Clinical Trial to Evaluate the Safety & Immunogenicity of SARS-COV-2 Vaccine (Vero Cell) Inactivated as A Booster Dose
The 2019 Coronavirus disease outbreak (COVID-19) was first reported at the end of 2019 in Wuhan China as a severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) infection. In less than a year, SARS-CoV-2 infection has become a pandemic and spread to almost all countries in the world, including Indonesia. World Health Organization data states that there are 4,240,479 confirmed cases of SARS-CoV-2 in Indonesia until 25 October 2021 with a death rate of 143,235 (WHO, 2021a). The Indonesian National Agency of Drug and Food Control (NA-DFC) has issued an Emergency Use Authorization for several SARS-COV-2 Vaccines, including the SARS-CoV-2 vaccine (Vero cell) inactivated produced by Sinopharm (BPOM, 2021). Clinical data that the actual immune responses decrease after several months are continuously being reported (Marmot et al., 2021), and the decrease of vaccine efficacy due to the appearance of variants is also known (Abu-Raddad et al., 2021; Lopez Bernal et al., 2021). These potential risks suggest the need for a booster dose or periodic booster doses of the SARS-COV-2 Vaccine. In fact, there is a study result given several months after vaccination, which leads to the generation of a higher immune responses (Pan H et al., 2021). Booster dose of SARS-COV-2 Vaccine will either induce a high level of antibody responses against original strain, or enhance the broadly formed T cell immunity regardless of mutant strain to improve individual protection.
A Randomized, Double-Blinded, Placebo-Controlled, Phase Ⅰ/Ⅱ Clinical Trial, to Evaluate the Safety and Immunogenicity of the SARS-CoV-2 Inactivated Vaccine in Healthy Adults Aged 18~59 Years
This study is a randomized, double-blinded, and placebo controlled phase Ⅰ/Ⅱ clinical trial of the SARS-CoV-2 inactivated vaccine manufactured by Sinovac Research & Development Co., Ltd. The purpose of this study is to evaluate the safety and immunogenicity of the experimental vaccine in healthy adults aged 18 59 Years.
Favipiravir terminates severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication. Accordingly, early administration of favipiravir to SARS-CoV-2-infected coronavirus disease 2019 (COVID-19) patients may be expected to suppress disease progression.
A randomized double-blind placebo-controlled trial was conducted to demonstrate efficacy of favipiravir in reducing disease progression in patients with mild COVID-19. The participants were unvaccinated patients with comorbidities and at risk of progression to severe disease. Patients were enrolled within 72 hours of disease onset and randomized to receive either favipiravir (1800 mg/dose on Day 1 followed by 800 mg/dose) or matching placebo twice daily for 10 days. The primary endpoint was the proportion of patients requiring oxygen therapy within 28 days of randomization.
The trial was discontinued after enrolling 84 patients due to slower than anticipated enrollment caused by rapid uptake of SARS-CoV-2-vaccines and the emergence of the Omicron variant. Results from the 84 patients demonstrated no significant difference in all clinical outcomes. In post-hoc analyses, favipiravir treatment showed higher efficacy in patients within 48 hours of onset. No deaths or severe adverse events were documented in the favipiravir group. Plasma concentrations of favipiravir from Day 2 onward were maintained above 40 μg/mL.
Conducting clinical trials for pathogens like SARS-CoV-2 that rapidly accumulate mutations leading to altered disease characteristics carries significant risks unless it can be done in a short period. Therefore, it would be important to prepare the comprehensive clinical trial platform that can appropriately and promptly evaluate drugs even under a pandemic.
Influence of variant-specific mutations, temperature and pH on conformations of a large set of SARS-CoV-2 spike trimer vaccine antigen candidates.
作者: Matthew Stuible ; Joseph D Schrag ; Joey Sheff ; Daria Zoubchenok ; Simon Lord-Dufour ; Brian Cass ; Denis L'Abbé ; Alex Pelletier ; Martin A Rossotti ; Jamshid Tanha ; Christian Gervais ; Roger Maurice ; Majida El Bakkouri ; Mauro Acchione ; Yves Durocher
SARS-CoV-2 subunit vaccines continue to be the focus of intense clinical development worldwide. Protein antigens in these vaccines most commonly consist of the spike ectodomain fused to a heterologous trimerization sequence, designed to mimic the compact, prefusion conformation of the spike on the virus surface. Since 2020, we have produced dozens of such constructs in CHO cells, consisting of spike variants with different mutations fused to different trimerization sequences. This set of constructs displayed notable conformational heterogeneity, with two distinct trimer species consistently detected by analytical size exclusion chromatography. A recent report showed that spike ectodomain fusion constructs can adopt an alternative trimer conformation consisting of loosely associated ectodomain protomers. Here, we applied multiple biophysical and immunological techniques to demonstrate that this alternative conformation is formed to a significant extent by several SARS-CoV-2 variant spike proteins. We have also examined the influence of temperature and pH, which can induce inter-conversion of the two forms. The substantial structural differences between these trimer types may impact their performance as vaccine antigens.
Divergence of variant binding/neutralizing antibodies following SARS-CoV-2 booster vaccines in myeloma: Impact of hybrid immunity.
作者: Mehul Suthar ; Alberto Moreno ; Kelly Manning ; Maryam Azeem ; Ajay Nooka ; Madison Ellis ; Renee Manalo ; Jeffrey Switchenko ; Bushra Wali ; Jonathan Kaufman ; Craig Hofmeister ; Nisha Joseph ; Sagar Lonial ; Kavita Dhodapkar ; Madhav Dhodapkar
We characterized virus-neutralization and spike-binding antibody profiles in myeloma patients following monovalent or bivalent-SARS-CoV-2 booster vaccination. Vaccination improves the breadth of binding antibodies but not neutralization activity against current variants. Hybrid immunity and immune imprinting impact vaccine-elicited immunity.