Vaccine development and technology for SARS‐CoV‐2: Current insight

Severe acute respiratory syndrome coronavirus 2 is associated with a severe respiratory disease in China, that rapidly spread across continents. Since the beginning of the pandemic, available data suggested the asymptomatic transmission and patients were treated with specific drugs with efficacy and safety data not always satisfactory. The aim of this review is to describe the vaccines developed by three companies, Pfizer‐BioNTech, Moderna, and University of Oxford/AstraZeneca, in terms of both technological and pharmaceutical formulation, safety, efficacy, and immunogenicity. A critical analysis of Phases 1, 2, and 3 clinical trial results available was conducted, comparing the three vaccine candidates, underlining their similarities and differences. All candidates showed consistent efficacy and tolerability; although some differences can be noted, such as their technological formulation, temperature storage, which will be related to logistics and costs. Further studies will be necessary to evaluate long‐term effects and to assess the vaccine safety and efficacy in the general population. Highlights The rapid development of SARS‐CoV‐2 vaccines has been possible because in the last 20 years there have been rapid improvements in vaccine development in different scientific areas, such as molecular biology, genetic engineering, nano‐materials and lipid nanotechnology. The first three SARS‐CoV‐2 vaccines developed by Pfizer–BioNTech, Moderna and the University of Oxford/AstraZeneca are described, in terms of technology, pharmaceutical formulation, safety, efficacy and immunogenicity. The main detectable difference concerns the technological formulation, influencing logistics: two of these are mRNA‐based vaccines encapsulated in LNPs, whereas one is a DNA‐based vaccine encapsulated in viral vector. mRNA‐based vaccines have an advantage over DNA ones, because mRNA is directly translated in the cytoplasm form ribosomes once inside the cell. Technological and scientific advances allowed the encapsulation of mRNA into custom‐designed LNPs that mimic the structural features of a viral vector. Efficacy and safety studies of Pfizer–BioNTech, Moderna and the University of Oxford/AstraZeneca vaccines are reported, to report the massive pharmaceutical innovation brought.