ABSTRACT
Vaccinations are one of the most successful initiatives of the new era in the public health sector. Different types of vaccines are available nowadays depending on the antigen used and the methods of delivery and administration. Conventional vaccines are produced from dead, attenuated, or inactivated pathogens. The antigen activates the body’s immune system to recognize the foreign body as a threat and kill the virus in question. Antigen proteins can be administered directly, naturally, to strengthen the immune response along with the adjuvant. However, safety and efficacy remain the two main issues in conventional vaccine production. Therefore, new vaccine formulations have been introduced to target the antigen at the worksite, reduce toxicity, increase the bioavailability of active compounds, and prolong release time, thus improving therapeutic efficacy and safety. Loading the antigen into different delivery platforms such as lipid vesicles, nanoparticles, microparticles, microemulsions, virus-like particles, embedding complex agents, and cyclodextrins is a promising current vaccine strategy. The current review focused on the most recent research on vaccine delivery systems and briefly described the design and development of the COVID-19 vaccine uploaded to these carriers. This paper also discusses the current situation and future scenarios in the field of vaccine production. © 2022. Bazigha K. Abdul Rasool et al. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License