Grant: Project Grant

Severe acute respiratory syndrome virus-2 (SARS-CoV-2), the causative agent of the COVID-19 pandemic, has led to multiple (4-6) waves of infections worldwide during the past two years. As of August 2023, there are >774M confirmed cases of COVID-19 and >7M deaths related to COVID-19 globally. The development of vaccines against SARS-CoV-2 has led to successful mass immunizations worldwide, mitigating the worldwide pandemic-related mortality to a great extent. Yet the evolution and rapid spread of new variants has prolonged the pandemic and highlighted a need to develop a universal vaccine which can prevent infections from all virulent and emerging SARS-CoV-2 strains. The current vaccines have a common spike antigen-based design from the Wuhan isolate, which is intended to elicit antibody responses against the SARS-CoV-2 spike protein. However, emerging SARS-CoV-2 variants, from alpha to omicron, result in the reduction of vaccine efficacy due to alterations in S protein. In addition, vaccine-induced immunity seems to be short-lived and declines in a short period. Therefore, there is a critical need for a new generation of vaccine, which can provide sustained protection against heterologous SARS-CoV-2 variants. Recently, we have discovered novel modified peptides from conserved epitopes of SARS-CoV-2 antigens, which induce multiple arms of protective immunity (cellular and humoral), as a universal vaccine candidate against SARS-CoV-2 variants. In the proposed work, we will investigate the protective immunity induced by the designed multi-epitopes containing modified-peptides, their nanoparticle formulation and a prime boost strategy with current vaccines. These studies will contribute significantly to the investigation of new vaccine approaches, will facilitate and accelerate the clinical development of an effective broadly-protective vaccine candidate for SARS-CoV-2 and its variants, and will have a major impact on the health of Canadians and people worldwide.