Research Theme

• Development of novel methods for evaluating vaccine effectiveness
• Analysis of antibody responses to respiratory infections (Influenza, COVID-19) and their vaccines

Keyword

• IgA antibodies
• Respiratory infections
• Influenza virus
• Intranasal vaccine

Overview of Research

• Currently, the development of intranasal vaccines, which involve spraying antigens onto the nasal mucosa, is progressing both domestically and internationally. Intranasal vaccines are considered one of the next-generation vaccines because, in addition to inducing serum IgG antibodies, they also elicit secretory IgA antibodies and cellular immunity on the respiratory mucosa. This response is expected to provide protection against infection and prevent severe disease by blocking human-to-human transmission of viruses. However, a globally standardized method for evaluating the effectiveness of intranasal vaccines does not yet exist, which poses a significant challenge. To address this issue, we are developing simple and practical methods for measuring secretory IgA antibody titers and cellular immune responses on the respiratory mucosa.
• There is still much that remains unclear about the details of antibody responses induced in the blood and at the site of infection—the respiratory mucosa—following infection with respiratory diseases such as influenza and COVID-19 or after vaccination. To enable a more detailed analysis of these antibody responses, we are developing evaluation systems using the antibody landscape technique, which visualizes the target antigen regions of antibodies, to assess cross-protective capabilities. In addition, we are establishing methods for evaluating various antibody isotypes and subclasses, and applying these systems to assess antibody responses in humans and animal models.