The Indian Institute of Science (IISc) researchers have created a heat-tolerant vaccine, which is believed to be effective against every existing strains of SARS-CoV-2 and could potentially be updated quickly to counter future variants. This article provides an in-depth overview of the vaccine’s development process, its unique attributes, and its potential impact on the ongoing global battle against COVID-19.
The Need for IISc’s Vaccine
As per IISc, the efficacy of current vaccines against most SARS-CoV-2 strains is proven; however, a quick mutation of the virus has caused a decline in their effectiveness. Hence, a new solution was required which could be adaptable with the changing nature of the virus.
Antigen Selection Process
In order to create a more robust vaccine, the IISc researchers analyzed various proteins present in the virus and selected two parts of SARS-CoV-2’s spike protein: the S2 subunit and the Receptor Binding Domain (RBD). The S2 subunit happens to be highly conserved and mutates less than the S1 subunit, which is targeted by most of the current vaccines. On the other hand, RBD is known to stimulate a robust immune response. By combining these selected components, the team created a hybrid protein named RS2.
Testing & Results
Once the hybrid protein RS2 was developed, the researchers tested its effects in mouse and hamster models. The results showed that the hybrid protein elicited a strong immune response, indicating its potential as a vaccine candidate.
Understanding the Key Elements
The receptor-binding domain – a key part of a virus located on its ‘spike’ domain – allows it to dock onto body receptors, gaining entry into cells and leading to infection. The spike (S) protein of SARS-CoV-2, which plays a significant role in receptor recognition and cell membrane fusion process, consists of two subunits, S1 and S2.
Characteristics of RS2 Antigen
The RS2 antigen showcases adaptability to variants. It can be customized to include the RBD area of any new SARS-CoV-2 variant including XBB.1.5 and JN.1. This attribute mitigates concerns related to the virus’s rapid mutation. From a storage and distribution perspective, the RS2 antigen does not require cold storage, as it can be stored at room temperature for a month. Its reduced production and distribution costs render it an economically viable option.
Previous Year Questions on COVID-19 Vaccines
In the 2022 UPSC Civil Services Examination, there were questions related to vaccines manufactured to prevent the COVID-19 pandemic. For instance, the candidates were asked about the platforms used by vaccines like Covishield from the Serum Institute of India, Sputnik V, and COVAXIN. The answer revealed that while the Serum Institute of India’s Covishield was not based on mRNA platform, Sputnik V was manufactured using a vector-based platform, and COVAXIN indeed is an inactivated pathogen-based vaccine.