mRNA-1273 is a vaccine candidate developed by the biotechnology company Moderna in collaboration with the National Institutes of Health. It is an mRNA-based vaccine designed to protect against the novel coronavirus, SARS-CoV-2. The vaccine works by delivering a small piece of the virus's genetic material into cells, where it instructs the cells to produce a viral protein that triggers an immune response. Clinical trials have shown promising results, with mRNA-1273 demonstrating efficacy in preventing COVID-19 and eliciting strong immune responses. The vaccine has received emergency use authorization in several countries and is being distributed globally as part of efforts to control the COVID-19 pandemic.