Nano-Enabled COVID-19 Vaccines: Meeting the Challenges of Durable Antibody Plus Cellular Immunity and Immune Escape

Abstract

At the time of preparing this Perspective, large-scale vaccination for COVID-19 is in progress, aiming to bring the pandemic under control through vaccine-induced herd immunity. Not only does this vaccination effort represent an unprecedented scientific and technological breakthrough, moving us from the rapid analysis of viral genomes to design, manufacture, clinical trial testing, and use authorization within the time frame of less than a year, but it also highlights rapid progress in the implementation of nanotechnology to assist vaccine development. These advances enable us to deliver nucleic acid and conformation-stabilized subunit vaccines to regional lymph nodes, with the ability to trigger effective humoral and cellular immunity that prevents viral infection or controls disease severity. In addition to a brief description of the design features of unique cationic lipid and virus-mimicking nanoparticles for accomplishing spike protein delivery and presentation by the cognate immune system, we also discuss the importance of adjuvancy and design features to promote cooperative B- and T-cell interactions in lymph node germinal centers, including the use of epitope-based vaccines. Although current vaccine efforts have demonstrated short-term efficacy and vaccine safety, key issues are now vaccine durability and adaptability against viral variants. We present a forward-looking perspective of how vaccine design can be adapted to improve durability of the immune response and vaccine adaptation to overcome immune escape by viral variants. Finally, we consider the impact of nano-enabled approaches in the development of COVID-19 vaccines for improved vaccine design against other infectious agents, including pathogens that may lead to future pandemics.

A Systematic Review on COVID-19 Vaccine Strategies, Their Effectiveness, and Issues

“…Vaccine development by nanotechnology improves nucleic acid delivery and conformationstabilized subunit vaccines to lymph nodes. It triggers cellular and humoral immunity, preventing viral infection and disease severity [157].…”

Cross-reactivity of antibodies from non-hospitalized COVID-19 positive individuals against the native and B.1.351 SARS-CoV-2 spike proteins

“…ACE-2 is particularly abundant on the surface of lower respiratory tract cells, which makes them susceptible to infection and can cause pneumonia (15,16). The antibodies produced in response to current vaccines work primarily by binding to the RBD of spike protein, thus blocking its interaction with ACE-2 (17), which is thought to mediate their effectiveness.…”

Antibacterial and antiviral high-performance nanosystems to mitigate new SARS-CoV-2 variants of concern

“…Nano-enabled antiviral vaccines have the most sought out, strongest, and efficient response to a viral outbreak. The efficacy predominately depends on the stability of its delivery vehicle, that are in nano regime [ 21 , 22 ]. For example, the lipid molecules in the mRNA-1273 from Moderna Inc. or the ChAdOx1 nCoV-19 from Oxford University require a non-replicating adenovirus vector, all of these can be considered as NSs.…”