Animals Antibodies, Viral COVID-19 3 SARS-CoV-2 3 Severe acute respiratory syndrome coronavirus 2 Spike Glycoprotein, Coronavirus 3 animal 3 coronavirus spike glycoprotein 3 genetics immunology 3 virus antibody 3 Article 2 CD4+ T lymphocyte 2 coronavirus disease 2019 2 human 2 immune response 2 immunoglobulin A 2 mucosal immunity 2 nonhuman 2 pandemic 2 prevention and control 2 spike protein, SARS-CoV-2 2 2009 H1N1 influenza 1 Ad5-S-nb2 vaccine 1 Administration, Intranasal 1 Antibodies, Neutralizing 1 Antibody 1 Antigens, Viral 1 BCG vaccine 1 Bagg albino mouse 1