Editorial: SARS-CoV-2: From Genetic Variability to Vaccine Design

The whole world has been at a standstill for more than 2 years now due to the pandemic of COVID-19, the disease caused by the SARS-CoV-2 virus. The first case of COVID-19 was detected in Wuhan, China in December 2019, and the rest, as they say, is history. The disease has claimed more than 6 million lives worldwide. SARS-CoV-2 is a positive-stranded RNA virus with a length of about 30 kb encompassing non-structural and structural proteins. Spike glycoprotein, a structural protein present on the virus surface plays an important role in binding with human ACE2 and other receptors. Since its detection in Wuhan, the virus has mutated several times and has given way to variants such as B.1.1.7 (Alpha), B.1.351 (Beta), B.1.525 (Eta), B.1.427/B.1.429 (Epsilon), B.1.526 (Iota), B.1.617.1 (Kappa), B.1.617.2 (Delta), C.37 (Lambda), P.1 (Gamma), P.2 (Zeta), P.3 (Theta), and B.1.1.529 (Omicron). In the initial days of the pandemic, there was little to no knowledge of this deadly virus. Thus, to understand the virus, whole genome analysis, and viral protein-based comparisons were carried out which concluded that SARS-CoV-2 is mostly related to bat SARS-like coronaviruses. Though there have been viruses like SARS-CoV-1 and MERS-CoV which belong to the same family of Coronaviridae just like SARS-CoV-2, outbreaks were sporadic and they did not cause global pandemics. Moreover, since the virus shared similarities with other viruses, its prediction was yet another challenge that the research community faced. Also, phylogenetic analyses were carried out by different researchers around the world to understand the virus mutations which mostly take place in the Spike glycoprotein. In fact, tools like Nextstrain have been used to visualize the virus evolution as well. These efforts by the researchers helped in a lot of ways to understand the virus’s spread and its mutations. However, the studies are mostly focused on the structural proteins, especially Spike glycoprotein of SARS-CoV-2 while research on non-structural proteins is still underway. Such proteins can be investigated further to understand the virus and its mutations better. The efforts of the researchers have also paved the way for the development of vaccines to fight against this deadly virus. There are several vaccines like Oxford-AstraZeneca, Pfizer-BioNTech, Moderna, Novavax, Covaxin, Sputnik V, and Johnson & Johnson which have been developed to date by scientists around the world. However, the developed vaccines are primarily designed to generate neutralizing antibodies against Spike glycoprotein. Moreover, due to the waning antibody response and some emerging variants like Omicron being somewhat resistant to the antibody response evoked by these vaccines, the long-term sustainability of these vaccines is a bit questionable. In this regard, T-cell responses against coronaviruses can last for a very long time which has been demonstrated by SARS and MERS viruses as well. All these factors have motivated us to have an issue on “SARS-CoV-2: From Genetic Variability to Vaccine Design” to benefit the scientific community. The articles covered in this issue are discussed in the subsequent section.