Option 1: The pair Covaxin and inactivated pathogen-based vaccine is correctly matched. Inactivated pathogen-based vaccines are made by killing the pathogen, usually with heat or chemicals, and then using it to create a vaccine. Covaxin is an example of an inactivated pathogen-based vaccine.

Option 2: The pair Covishield and mRNA vaccine is incorrect. Covishield is not an mRNA vaccine. It is a viral vector-based vaccine. Viral vector vaccines use another virus (the vector) to deliver a protein or genetic material into cells to provoke an immune response. Covishield is based on the viral vector ChAdOx1, which is derived from a weakened version of a common cold virus (adenovirus) that infects chimpanzees.

Option 3: The pair Sputnik V and viral vector-based vaccine is correctly matched. Sputnik V is a viral vector-based vaccine developed by the Gamaleya Research Institute in Russia. It uses two different adenoviruses as vectors to deliver genetic material from the SARS-CoV-2 virus (which causes COVID-19) into cells to stimulate an immune response.

Option 4: The answer is not valid, as only options 1 and