Review of COVID-19 mRNA Vaccines: BNT162b2 and mRNA-1273

Abstract

The United States Food and Drug Administration recently issued emergency use authorization for 2 mRNA vaccines for preventing COVID-19 disease caused by SARS-CoV-2 virus infections. BNT162b2 from Pfizer-BioNTech and mRNA-1273 by Moderna are planned for use in mass-immunization programs to curb the pandemic. A brief overview of COVID-19 mRNA vaccines is provided, describing the SARS-CoV-2 RNA, how mRNA vaccines work and the advantages of mRNA over other vaccine platforms. The Pfizer-BioNTech collaboration journey to short-list mRNA vaccine candidates and finally selecting BNT162b2 based on safety data is outlined, followed by the Phase 3 study of BNT162b2 demonstrating 95% efficacy in preventing COVID-19 infections. Studies regarding mRNA-1273 (Moderna) are described, including extended immunogenicity data up to 119 days. The Phase 3 COVE study of mRNA-1273 eventually showed vaccine efficacy of 94.5%. Recommendations for future mRNA vaccine development are provided, including ongoing safety surveillance, evaluation in under-represented groups in previous studies and improving mRNA vaccine thermostability. Finally, further logistical considerations are required for manufacturing, storing, distribution and implementing mass vaccination programs to curb the pandemic.