What are viral vector-based vaccines and how could they be used against COVID-19?

Viral vector-based vaccines differ from most conventional vaccines in that they don’t actually contain antigens, but rather use the body’s own cells to produce them. They do this by using a modified virus (the vector) to deliver genetic code for antigen, in the case of COVID-19 spike protein found on the surface of the virus, into human cells. By infecting cells and instructing them to make large amounts of antigen, which then trigger an immune response, the vaccine mimics what happens duringbnatural infection with certain pathogens-especially viruses. This has the advantage of triggering a strong cellular immune response by T cells as welll the production of antibodies by B cells. An axample of a viral vector vaccine is the rVSV-ZEBOV vaccine gainst Ebola.