Early clinical trial data in for whole virus COVID-19 vaccine candidate

The currently deployed coronavirus disease 2019 (COVID-19) vaccines are either mRNA or adenovirus vector-based, though several others have been or are in development. Several whole-virion inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have demonstrated good efficacy in early clinical trials, particularly in combination with an aluminum adjuvant (a substance that gives a stronger immune response), which is more effective than the more commonly used alum adjuvant alone. In a study uploaded to the preprint server medRxiv, the efficacy of one such vaccine, termed VLA2001, was determined by giving the vaccine to healthy adult volunteers, which generated a robust immune response with evidence of T-cell activation. How was the study performed? The VLA2001 vaccine was formulated with aluminum hydroxide adjuvant and cytosine phospho-guanine, a toll-like receptor 9 agonist that stimulates the production of proinflammatory cytokines. It was distributed to 153 individuals in two doses at three differing dose sizes. Neutralizing antibody titers...