An influenza vaccine made up of nanoparticles and given through the nose improves the body’s immune response to influenza virus infection and offers broad protection against different strains of the virus, according to researchers at the Institute for Biomedical Sciences at Georgia State University .
Recurring seasonal influenza epidemics and potential pandemics are among the most serious threats to public health. Current seasonal influenza vaccines induce strain-specific immunity and are less effective against unpaired strains. Widely protective influenza vaccines are urgently needed.
Intranasal vaccines are a promising strategy for combating infectious respiratory diseases, such as influenza. They are more effective than vaccines injected into a muscle because they can induce mucosal immune responses in the airways, preventing infection at the gateway to the virus. They can also stimulate systemic immune responses throughout the body.
Scientists can overcome vaccine safety concerns and the long production phase of virus-based influenza vaccines by constructing intranasal vaccines with recombinant proteins or peptides. However, these vaccines are poor at producing immune responses, so there is a need for strong mucosal adjuvants, substances that enhance the body’s immune response to antigens (the molecular structures of pathogens). The lack of suitable mucosal adjuvants currently hinders the development of such a vaccine.
In this study, researchers developed an intranasal influenza vaccine using recombinant hemagglutinin (HA), a protein found on the surface of influenza viruses, as the antigenic component of the vaccine. HA is integral to the influenza virus’ ability to cause infection.
They also created a two-dimensional nanomaterial (graphene oxide nanoparticles functionalized with polyethyleneimine) and found that it exhibited potent adjuvant (immunostimulant) effects on influenza vaccines administered intranasally. The results are published in the journal Proceedings of the National Academy of Sciences.
“Conventional influenza vaccines primarily induce antibody responses,” said Dr. Baozhong Wang, lead author of the study, lead investigator of the National Institutes of Health grant supporting the study, and professor at the Institute of Science biomedical. “However, recent research shows that the responses of memory T cells residing in the lungs are essential for optimal cross-protection against pulmonary influenza infection. The development of T cell responses residing in the lungs requires respiratory vaccination or influenza virus infection. for the development of needleless and logistically simplified intranasal influenza vaccines for cross-protection. “
“In our study, we reported for the first time that two-dimensional graphene oxide nanomaterials had a potent adjuvant effect in stimulating the immune responses of intranasal vaccines to hemagglutinin (HA),” said Dr. Chunhong Dong, lead author of the study and a Postdoctoral Fellow in the laboratory of Dr Baozhong Wang at the Institute of Biomedical Sciences.
“This study provides new insights into the development of high performance intranasal vaccine systems with two-dimensional sheet-shaped nanoparticles,” said Dong. “Graphene oxide nanoparticles have extraordinary attributes for drug delivery or vaccine development, such as the very large surface area for loading antigens at high density, and the vaccine has shown immuno- Superior improvement in vitro and in vivo. The nanoplatform could be easily adapted for the construction of mucosal vaccines for different respiratory pathogens. “
The study, conducted in mice and in cell culture, found that the nanoparticles dramatically improved immune responses at mucosal surfaces and throughout the body in mice. Robust immune responses conferred immune protection against influenza virus challenge by homologous virus strains (same) and heterologous virus strains (different).
The results are also promising as needle-free intranasal influenza vaccines possess superior logistical advantages over traditional injectable vaccines, such as easy administration with high acceptance for recipients and prevention of biohazardous waste.
Study co-authors include Dr Chunhong Dong, Ye Wang, Gilbert Gonzalez, Yao Ma, Yufeng Song, Dr Sang-Moo Kang and Dr Baozhong Wang from the Georgia State Institute of Biomedical Sciences. and Shelly Wang and Dr. Richard W. Compans of Emory University School of Medicine.
The study was funded by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health.