Safety and immunogenicity of a booster dose of S-268019-b: Interim findings of a Phase 3, open-label clinical study in Japan.

Despite the initial success of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in prevention of symptomatic and severe diseases, booster vaccination has become increasingly important with the advent of variants with immune-escaping capacity. Herein, we report the safety and immunogenicity of S-268019-b, comprising SARS-CoV-2 spike protein and a squalene-based adjuvant, as a booster dose. We performed an interim analysis of an open-label, Phase 3 study data until Day 29 following S-268019-b booster in Japanese adults (aged 20-64 years) who had completed primary vaccination with mRNA-1273 and in Japanese elderly (aged ≥ 65 years) who had completed primary vaccination with mRNA-1273 or BNT162b2.

Immune response and protective efficacy of the SARS-CoV-2 recombinant spike protein vaccine S-268019-b in mice.

Vaccines that efficiently target severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent for coronavirus disease (COVID-19), are the best means for controlling viral spread. This study evaluated the efficacy of the COVID-19 vaccine S-268019-b, which comprises the recombinant full-length SARS-CoV-2 spike protein S-910823 (antigen) and A-910823 (adjuvant). In addition to eliciting both Th1-type and Th2-type cellular immune responses, two doses of S-910823 plus A-910823 induced anti-spike protein IgG antibodies and neutralizing antibodies against SARS-CoV-2.

Homologous and heterologous booster vaccinations of S-268019-b, a recombinant S protein-based vaccine with a squalene-based adjuvant, enhance neutralization breadth against SARS-CoV-2 Omicron subvariants in cynomolgus macaques.

SARS-CoV-2 Omicron subvariants such as BA.2.12.

Immunogenicity and safety of booster dose of S-268019-b or BNT162b2 in Japanese participants: An interim report of phase 2/3, randomized, observer-blinded, noninferiority study.

In this randomized, observer-blinded, phase 2/3 study, S-268019-b (n = 101), a recombinant spike protein vaccine, was analyzed for noninferiority versus BNT162b2 (n = 103), when given as a booster ≥6 months after 2-dose BNT162b2 regimen in Japanese adults without prior SARS-CoV-2 infection. Interim results showed noninferiority of S-268019-b versus BNT162b2 in co-primary endpoints for neutralizing antibodies on day 29: geometric mean titer (GMT) (124.97 versus 109.

Immunogenicity and protective efficacy of SARS-CoV-2 recombinant S-protein vaccine S-268019-b in cynomolgus monkeys.

The vaccine S-268019-b is a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S)-protein vaccine consisting of full-length recombinant SARS-CoV-2 S-protein (S-910823) as antigen, mixed with the squalene-based adjuvant A-910823. The current study evaluated the immunogenicity of S-268019-b using various doses of S-910823 and its vaccine efficacy against SARS-CoV-2 challenge in cynomolgus monkeys. The different doses of S-910823 combined with A-910823 were intramuscularly administered twice at a 3-week interval.

Hamster PIWI proteins bind to piRNAs with stage-specific size variations during oocyte maturation.

In animal gonads, transposable elements are actively repressed to preserve genome integrity through the PIWI-interacting RNA (piRNA) pathway. In mice, piRNAs are abundantly expressed in male germ cells, and form effector complexes with three distinct PIWIs. The depletion of individual Piwi genes causes male-specific sterility with no discernible phenotype in female mice.

Gene expression ontogeny of spermatogenesis in the marmoset uncovers primate characteristics during testicular development.

Mammalian spermatogenesis has been investigated extensively in rodents and a strictly controlled developmental process has been defined at cellular and molecular levels. In comparison, primate spermatogenesis has been far less well characterized. However, important differences between primate and rodent spermatogenesis are emerging so it is not always accurate to extrapolate findings in rodents to primate systems.

Small RNA profiling and characterization of piRNA clusters in the adult testes of the common marmoset, a model primate.

Small RNAs mediate gene silencing by binding Argonaute/Piwi proteins to regulate target RNAs. Here, we describe small RNA profiling of the adult testes of Callithrix jacchus, the common marmoset. The most abundant class of small RNAs in the adult testis was piRNAs, although 353 novel miRNAs but few endo-siRNAs were also identified.