Abstract Text: The pandemic caused by SARS-CoV-2 has led to 546 million cases and 6.3 million deaths worldwide. The receptor binding domain (RBD) of SARS-CoV-2 has emerged as the prime vaccine candidate. Purified RBD is, however, weakly immunogenic and requires the use of multiple doses and adjuvants. Further, all the current SARS-CoV-2 vaccines require cold chain storage that incurs heavy cost. Biodegradable polymer particles as vaccine delivery system offer the advantages of improved immunogenicity, stability and modulation of immune response. In the current investigation, RBD of SARS-CoV-2 was delivered through polymer particles and evaluated in mice model. Results suggest that polymer particles are capable of mounting better and sustained antibody response without the use of alum. Further, the particles showed improved stability and could be safely stored outside cold chain. Thus, using biodegradable polymer particles for vaccine delivery offer improved immunogenicity and reduce reliance on cold chain. This can significantly reduce cost and increase the access of vaccines to resource limited settings given the inequitable distribution still looms the pandemic.
