Related Experiment Video
Updated: Oct 16, 2026
Intranasal Administration of Recombinant Influenza Vaccines in Chimeric Mouse Models to Study Mucosal Immunity
Published on: June 25, 2015
Intranasal immunization expressing S1 antigen can confer functionally sterile protection against an intranasal
Hiroshi Ishii1, Kosuke Miyauchi2, Shigeyoshi Harada3
1Department of Latent Infection, National Institute of Infectious Diseases, Japan Institute for Health Security, Tokyo, 162-8640, Japan.
Abstract:
Currently approved COVID-19 vaccines have shown significant protective efficacy against disease onset and progression after SARS-CoV-2 infection. However, systemic immune responses induced by intramuscular vaccination have limited impact on protection of viral transmission. Intranasal vaccination is an important strategy for induction of mucosal immune responses for protection of viral transmission. Here, we investigated the potential of intranasal immunization expressing a SARS-CoV-2 spike (S) antigen to prevent SARS-CoV-2 infection in a mice model. Intranasal immunization with a Sendai virus vector expressing SARS-CoV-2 S1 domain fused with the trimerization domain of T4 fibritin induced neutralizing antibodies detected not only in plasma but also in bronchoalveolar lavage fluid (BALF) in BALB/c mice. After an intranasal challenge with a mouse-adapted SARS-CoV-2 strain QHmusX, all the unimmunized mice (n = 9) showed significant body weight loss and high viral load in BALF. In contrast, the intranasally-immunized mice (n = 8) had no detectable viral sgRNA nor infectious viruses in BALF except for one mouse with marginal level of sgRNA, showing no body weight loss. This study indicates that intranasal immunization expressing S1 antigen can confer functionally sterile protection against SARS-CoV-2 infection.
