Importantly, this was the first study of an inactivated SARS-CoV-2 vaccine to include participants older than 60 years—the most vulnerable age group for this infection. In the phase 1 dose-escalating trial, the vaccine was given at a two-dose schedule at three different concentrations (2 μg, 4 μg, and 8 μg per dose) and was well tolerated in both age groups (18–59 years and ≥60 years). The older age group had lower rates of solicited adverse events than the younger adults: the overall rates of adverse events within 28 days after vaccination were 34 (47%) of 72 participants in the group aged 18–59 years, compared with 14 (19%) of 72 participants in the group aged 60 years and older. At the same time, in both age groups the vaccine was similarly immunogenic: the geometric mean anti-SARS-CoV-2 neutralising antibody titres measured by a 50% virus neutralisation assay 14 days after the booster dose were 88, 211, and 229 in the group aged 18–59 years and 81, 132, and 171 in the group aged 60 years and older for 2 μg, 4 μg, and 8 μg vaccine doses, respectively. Moreover, the authors tested cross-reactivity of the neutralising antibodies against several drifted SARS-CoV-2 isolates and showed the potential of their vaccine to protect against evolutionary diverged viruses, should they appear in circulation.
The current study is the second to report the interim results of safety and immunogenicity of inactivated SARS-CoV-2 vaccine, with the first being the another β-propiolactone inactivated aluminium-adjuvanted whole-virion SARS-CoV-2 vaccine developed by Wuhan Institute of Biological Products.
Both studies showed very similar levels of adverse events and neutralising antibody titres post vaccination, which indicates the reproducibility of clinical results of similar vaccine modes produced by different manufacturers.
All good news of course, and this vaccine exists right now. Just not for you! Here is the piece from The Lancet, and here is associated commentary, also seeming to confirm the positive results. A phase III trial is underway in the UAE to measure efficacy. I cannot speak to data reliability issues, but presumably the referees at The Lancet find this credible enough to recommend publication.
Via Alan Goldhammer.