Cholera vaccine delivered through a cup of rice water

Vaccinations against prevalent pathogens could be ingested as oral or inhaled as nasal vaccines, this is due to the development of non-invasive vaccines, which target the mucous membranes. These could help fight a plethora of infectious diseases such as cholera, typhoid, rotavirus, norovirus, influenza and Streptococcus pneumoniae.

Researchers at the International Research and Development Center for Mucosal Vaccines (IMV), the Institute of Medical Science, the University of Tokyo (IMSUT) have developed a rice-based oral vaccine called MucoRice and nanogel-based nasal vaccines for immunity against intestinal and respiratory infections caused by Vibrio cholerae and S. pneumoniae, respectively.

Most pathogens enter our bodies through mucosal surfaces in our respiratory, digestive and reproductive tracts. The protective immunity at local mucosal sites as well as whole-body (systemic) can be induced as mucosal vaccines are delivered through many routes including oral, nasal, ocular, rectal or sublingual administration.

Rice-inspired breakthroughs

Kiyono’s group initiated the MucoRice Project in 2003, as part of a new mucosal immunology program at IMSUT. This led to MucoRice-CTB, the world’s first genetically modified strain of rice, which carries a vaccine antigen for V. cholerae-induced diarrhea. The AMED Translational Research Network Program bolstered phase I clinical trials with healthy human volunteers. The project is in collaboration with Astellas Pharma Inc., based in Tokyo, Japan.

International partnerships

Researchers at the IMV have also lately developed a nanogel-based pneumococcal surface protein A (PspA) nasal vaccine, in collaborations with Kyoto University and the University of Alabama at Birmingham. The project is promising preclinical results led to the establishment of a venture company, HanaVax Inc, in 2016 and is headed by Yoshikazu Yuki in Kiyono’s team. Diversity is key to advancing mucosal immunology and vaccinology related fundamental and translational research. Their aim is to facilitate borderless interaction.