A group around Dr. GAO Lizeng from the CAS Institute of Biophysics (IBP) has found that a chitosan- functionalized iron oxide nanozyme (IONzyme) functions as a catalytic adjuvant to enhance nasal mucosal immunity. The modified nanozyme combines with flu virus particles loaded with negative charges to produce the composites of nanozyme and inactivated flu virus, thus promoting the delivery of vaccines to mucosal targets and the formation peroxides in the acidic lysosomes, enhancing the level of ROS. When experimental mice were given intranasal immunization twice with a combination of a H1N1 whole inactivated virus complex, a 100% protective immunity against influenza viruses was achieved compared to 30% with the vaccine without IONzyme. 

CAS news release, August 27, 2020a