A single dose of recombinant adenoviral vector rabies vaccine expressing two copies of glycoprotein protects mice from lethal virus challenge.

INTRODUCTION: Rabies is a fatal infectious disease, that poses a major public health threat in developing countries. With an annual death toll of approximately 59,000, more than half of which are children, an urgent need exists for a safe, affordable, and effective preventive measure against rabies virus infection. METHODOLOGY: A recombinant rabies vaccine called Ad5-dRVG was constructed by introducing two copies of the rabies virus glycoprotein into a human adenoviral vector. Virus-neutralizing assays and virus challenge experiments were employed to evaluate the Ad5-dRVG vaccine. RESULTS: Our findings demonstrate that a single dose of Ad5-dRVG, administered either intramuscularly or orally, elicited significantly stronger immune responses than Ad5-RVG. Moreover, both vaccines provided complete protection in mice. Notably, the vaccine exhibited remarkable efficacy even at low doses, suggesting potential cost reduction in production. CONCLUSIONS: The development of the Ad5-dRVG recombinant rabies vaccine represents a significant advancement in rabies prevention. Its enhanced immunogenicity, demonstrated efficacy and potential cost savings make it a promising candidate for widespread use.

Recombinant chimpanzee adenovirus AdC7 expressing dimeric tandem-repeat spike protein RBD protects mice against COVID-19.

A safe and effective vaccine is urgently needed to control the unprecedented COVID-19 pandemic. Four adenovirus-vectored vaccines expressing spike (S) protein have been approved for use. Here, we generated several recombinant chimpanzee adenovirus (AdC7) vaccines expressing S, receptor-binding domain (RBD), or tandem-repeat dimeric RBD (RBD-tr2). We found vaccination via either intramuscular or intranasal route was highly immunogenic in mice to elicit both humoral and cellular immune responses. AdC7-RBD-tr2 showed higher antibody responses compared to either AdC7-S or AdC7-RBD. Intranasal administration of AdC7-RBD-tr2 additionally induced mucosal immunity with neutralizing activity in bronchoalveolar lavage fluid. Either single-dose or two-dose mucosal administration of AdC7-RBD-tr2 protected mice against SARS-CoV-2 challenge, with undetectable subgenomic RNA in lung and relieved lung injury. AdC7-RBD-tr2-elicted sera preserved the neutralizing activity against the circulating variants, especially the Delta variant. These results support AdC7-RBD-tr2 as a promising COVID-19 vaccine candidate.

A transcriptomic taxonomy of Drosophila circadian neurons around the clock.

Many different functions are regulated by circadian rhythms, including those orchestrated by discrete clock neurons within animal brains. To comprehensively characterize and assign cell identity to the 75 pairs of Drosophila circadian neurons, we optimized a single-cell RNA sequencing method and assayed clock neuron gene expression at different times of day. The data identify at least 17 clock neuron categories with striking spatial regulation of gene expression. Transcription factor regulation is prominent and likely contributes to the robust circadian oscillation of many transcripts, including those that encode cell-surface proteins previously shown to be important for cell recognition and synapse formation during development. The many other clock-regulated genes also constitute an important resource for future mechanistic and functional studies between clock neurons and/or for temporal signaling to circuits elsewhere in the fly brain.