A cell line of Accession No. NITE P-03458. A producing method of a cell line includes: a transfection step of transfecting a vector into a cell, where the vector includes a nucleic acid sequence encoding a nonstructural protein of a coronavirus, a reporter protein including a drug-resistant protein, and a structural protein of the coronavirus; and a selection step of performing selection on the cell obtained in the transfection step using a drug.

A method of treating a viral infection in a subject in need thereof is disclosed. The method comprising administering to the subject a therapeutically effective amount of cell-derived vesicles comprising wild-type p53. Methods of inducing cell cycle arrest and/or apoptosis of a virally infected cell are also disclosed.

The disclosure provides compositions and methods for generating polyclonal antibodies, for example, using circular polyribonucleotides and non-human animals having humanized immune systems.

A packaging system for a coronavirus pseudovirus, including a vesicular stomatitis virus (VSV) vector in which Fluc and EGFP dual-reporter genes replace a GP gene, and packaging cell that expresses a coronavirus spike protein. The packaging system may quickly package pseudoviruses by using a one-step packaging method, and may be used in the research of coronaviruses such as COVID-19 (SARS-CoV-2), SARS (SARS-CoV) and MERS, and other viruses. The packaging system and thereby pseudovirus method may also be used to evaluate the efficacy of disinfectants by means of virus contamination distribution models, setting up scenarios, and sampling and testing steps.