Exploring the possible use of saponin adjuvants in COVID-19 vaccine

ABSTRACT

There is an urgent need for a safe, efficacious, and cost-effective vaccine for the coronavirus disease 2019 (COVID-19) pandemic caused by novel coronavirus strain, severe acute respiratory syndrome-2 (SARS-CoV-2). The protective immunity of certain types of vaccines can be enhanced by the addition of adjuvants. Many diverse classes of compounds have been identified as adjuvants, including mineral salts, microbial products, emulsions, saponins, cytokines, polymers, microparticles, and liposomes. Several saponins have been shown to stimulate both the Th1-type immune response and the production of cytotoxic T lymphocytes against endogenous antigens, making them very useful for subunit vaccines, especially those for intracellular pathogens. In this review, we discuss the structural characteristics, mechanisms of action, structure–activity relationship of saponins, biological activities, and use of saponins in various viral vaccines and their applicability to a SARS-CoV-2 vaccine.

KEYWORDS:

• Saponin adjuvant
• immunostimulation
• viral vaccines
• COVID-19 vaccine

Acknowledgments

The mini-review paper was supported by the research project, IVRI/PALAM/17-19/013 and for this we gratefully acknowledge the Director, ICAR-IVRI, Izatnagar, Bareilly, Uttar Pradesh, India.

Author contributions

RS conceptualized and designed the review. AP and RS wrote the manuscript. KD and RS critically edited the manuscript. GM, BS and KPS collected literature and reviewed the manuscript. All the authors read and approved the final manuscript.

Disclosure of potential conflicts of interest

All authors declare that there exist no commercial or financial relationships that could, in any way, lead to a potential conflict of interest.

Additional information

Funding

No funding was required to write this review.