Safety and immunogenicity of COVAC-2, a Sepivac SWE™ adjuvanted SARS-CoV-2 recombinant protein vaccine in healthy adults; a randomized controlled first-in-human dose-escalation trial
Bibliographic record
Abstract
BACKGROUND: This first-in-human dose-escalating, randomized, placebo-controlled, observer-blinded study assessed the safety and immunogenicity of a recombinant protein vaccine (COVAC-2) composed of the S1 subunit of the spike protein of SARS-CoV-2 formulated with the oil-in-water adjuvant Sepivac SWE™. METHODS: Healthy adults (n = 61) with no known prior exposure to SARS-CoV-2 virus or vaccines were enrolled into one of two cohorts, based on age, 18-54 years old (n = 34, Cohort 1) or 55+ years (n = 27, Cohort 2). Participants in both cohorts were randomized to a two-dose schedule of 25 μg, 50 μg, or 100 μg (cohort 1 only) of COVAC-2 vaccine, or placebo on Days 0 and 28. Safety and immunogenicity data were collected from study Day 0 to 365. RESULTS: The most common adverse events were injection site pain, generalized muscle aches, and headaches in all dose levels and age groups. Most events were grade 1 and 2 in severity but one participant in the 100 μg dose group reported grade 3 adverse events. S1 subunit-specific humoral binding and neutralizing antibody titres peaked with a geometric mean of 817 IU/mL and 168 IU/mL, respectively, in groups vaccinated with COVAC-2 between study Day 42 and 56 and then decreased in the absence of authorized vaccine administration or infection with SARS-CoV-2. Seroconversion in both 18-54 and 55+ cohorts required two doses of vaccine with 100 % of participants seroconverting by Day 42 in the 18-54 cohort and 88 % of participants by Day 42 in the 55+ cohort. No clear T cell response was detected when measuring IFNγ or IL-5 in peripheral blood mononuclear cells following stimulation with SARS-CoV-2 peptides. CONCLUSIONS: This Phase 1 trial indicated that COVAC-2 is safe and induces high levels of both antigen-specific binding and neutralizing antibodies by Day 42-56 with levels beginning to wane by Day 120.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.002 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".