Developmental biology of Corona vaccine: lipid nanoparticle mRNA-encapsulation, a safe approach

The global pandemic of COVID-19 is progressing rapidly across the world and declared as health emergency. The novel Coronavirus can cause severe lower respiratory tract infections primarily in geriatric, immunocompromised persons, infants and patients with comorbidities, or genetic disorders. Few Emergency Use Authorizations (EAUs) have been granted by FDA and other regulatory bodies with an aim to repurpose the existing approved medicines to fight the disease, and till date no specific treatment methodologies or preventive measures are available. At present, numerous medications which are already approved for other therapeutic indications, as well as the new medications, are undergoing clinical trials for the evaluation of safety and efficacy against COVID-19 infection. These therapeutic ranges include antimalarial, antiviral, steroids, convalescent plasma containing antibodies, and immune modulators, etc. Nevertheless, the primary focus is on preventive care and currently more than hundred potential vaccine candidates are under development by leading biotech companies across the globe which are at different phases of clinical development. Lipid based mRNA delivery, DNA delivery and mAbs are the most advanced technologies being embraced besides whole-virion inactivated vaccine, attenuated live vaccine, non-replicating viral vector-based vaccine, protein single unit vaccine and multiunit vaccine. This review focuses on the current progress in drug delivery systems of COVID-19 vaccine across industries, academics, and government funded research institutes with a special focus on the synthetic mRNA-based lipid nanoparticle (LNP).