The ongoing COVID-19 pandemic is shining a bright spotlight on vaccine development.
As numerous vaccines race through clinical trials, physicians and researchers continue to work on developing new vaccine technologies to generate the most effective vaccines with the fewest side effects.
In a new study, researchers found the potential for one vaccine platform, which uses self-assembling peptide nanofibers tagged with antigens to prime the immune system against a potential invasion.
They found that these nanofibers can induce an immune response and activate T cells without the use of additional adjuvants, which can induce inflammation and are linked to common vaccine side effects, like soreness at the injection site or low-grade fever.
The research was conducted by a team at the University of Chicago and Duke University
Lining the surfaces of the lungs and intestines, dendritic cells act as the first point of contact for the innate immune system.
These cells bind to and gobble up the antigens found on the surface of invading pathogens, then turn around and present the antigens on their own cell surface to other immune system cells, including T and B cells.
This allows the T cells to initiate an immune response and prepare to defend the body against the invading bacteria, fungus or virus.
In the study, the researchers leveraged their nanofiber platform to test a specific kind of vaccine, called a subunit vaccine, which only uses a specific protein intended to act as the main antigen to stimulate an immune response.
This is in contrast to other kinds of vaccines, such as live-attenuated vaccines or inactivated vaccines, which challenge the immune system by introducing the whole virus, in a less virulent or inactive form.
Each type of vaccine has its advantages and disadvantages; live-attenuated vaccines can offer the most protection, but because they contain the actual pathogen, they frequently can’t be used for patients with weakened immune systems.
The team says the major advantage of subunit vaccines is safety since they don’t involve the replication of live pathogens.
On the other hand, to increase their effectiveness, subunit vaccines require adjuvants and repeated doses to induce long-lasting immunity against a disease.
Adjuvants have the big downside of provoking inflammation. This makes it difficult to find the balance between getting a strong enough immune response and making the vaccine as safe and side-effect-free as possible.
The new platform does not require adjuvants. The means the peptides are quite heat stable, and can be delivered as a dry powder to be reconstituted into nanofibers on site, making it easier to get vaccines into resource-limited areas.
The researchers believe that the primary strength of their nanofiber scaffolding is that it provides a physical structure that presents the antigens to the dendritic cells, making it easier for the innate immune system to recognize the antigens and begin a response.
While the study was intended primarily to uncover the mechanism by which the nanofibers can induce an immune response, the results also demonstrate that this platform has great potential for generating safe, effective intranasal vaccines.
This platform would also allow physicians and scientists to more precisely dial in the immune response to provide the best protection against disease.
They provided the example of SARS-CoV-2, the novel coronavirus that causes COVID-19, as an example where being able to fine-tune the immune response and delivering the vaccine directly to the most affected tissues could be beneficial.
One author of the study is Anita Chong, Ph.D., a professor of surgery at the University of Chicago Medicine.
The study is published in Science Advances.
Copyright © 2020 Knowridge Science Report. All rights reserved.
