Researchers from the Institute of Process Engineering (IPE) of the Chinese Academy of Sciences have proposed a new concept of "nanomicro composite" delivery and developed a single-dose dry-powder inhalable vaccine platform with a nanomicro composite multilevel structure against the future emerging and epidemic infectious diseases. The study was published in Nature.
In recent years, researchers have made significant progress in developing vaccines for respiratory infectious diseases. Most of these vaccines are administered through intramuscular injection, which primarily induces humoral immune responses and relies on blood antibodies to neutralize the virus. However, this approach fails to trigger mucosal immune responses and establish a robust immune barrier in the respiratory tract.
The adjuvants commonly used in combination with current vaccines, such as aluminum adjuvants, are unable to induce cellular immune responses and are ineffective in combating rapid viral mutations. Besides, the current liquid form of vaccines necessitates strict low-temperature storage conditions, and the two or three-dose vaccination schedule impacts the overall vaccination rate. There is an urgent need for interdisciplinary integration and innovative research concepts to develop safer and more efficient vaccines for respiratory infections.
In this study, Prof. MA Guanghui and Prof. WEI Wei from IPE, in collaboration with Prof. WANG Hengliang and ZHU Li from State Key Laboratory of Pathogen and Biosecurity, have developed a new vaccine platform to tackle these challenges.
This platform combines sustained-release microspheres with protein antigen nanoparticles. The nanoparticles' surface can simultaneously display multiple antigens, inducing a broad-spectrum immune response and expanding the range of vaccine protection. It also allows for the quick and convenient construction of other respiratory virus vaccines due to the flexibility of antigen presentation.
Besides, the platform's unique nano-micro composite structure enables efficient immune responses in the lungs by facilitating high-performance delivery. The antigen-nanoparticles can be efficiently taken up by antigen-presenting cells once they are released.
Moreover, this dry powder vaccine significantly reduces storage and transportation costs, making it suitable for areas with limited refrigeration facilities and improving immunization rates.
The sustained release of antigens in the vaccine induces long-lasting humoral, cellular, and mucosal immunity with just a single inhalation. Collaborating with Prof. HE Zhanlong from the Institute of Medical Biology of Chinese Academy of Medical Sciences, the researchers constructed the model of airborne protection, close contact protection and airborne transmission blocking, which effectively prevented the infection and transmission of the virus.
"The components of this nano-micro system used natural proteins and approved polymer materials, and the effectiveness and safety of the vaccine have been systematically studied in non-human primates, indicating its great potential for clinical translation," said Prof. WEI.
