Sinovac given for Covid-19 is a

1. A

   Protein sub-unit

   Protein sub-unit. This option claims Sinovac uses purified viral proteins to trigger immunity, which is incorrect because it is not a subunit vaccine.

2. B

   Non-replicating viral vector

   Non-replicating viral vector. This option asserts that Sinovac utilizes a modified harmless virus to deliver genetic material, which describes vaccines like Covishield rather than Sinovac.

3. C

   Whole virus vaccine

   Whole virus vaccine. This option states that Sinovac (CoronaVac) is an inactivated whole virus vaccine produced by growing the coronavirus in a lab and then killing it, making it the correct and most comprehensive mechanism among the choices provided.

4. D

   mRNA vaccine

   mRNA vaccine. This option claims that Sinovac injects genetic instructions for viral spike proteins, which applies to Pfizer or Moderna, not this inactivated vaccine.

Summary. Official key is (c) Whole virus vaccine. Sinovac, widely known as CoronaVac, relies on an inactivated pathogen approach where the SARS-CoV-2 virus is chemically inactivated so it cannot replicate. Aspirants often confuse inactivated whole virus vaccines with viral vector or protein subunit types due to similar naming conventions. Understanding the manufacturing platform helps differentiate vaccines like Covaxin and Sinovac from mRNA or vector formulations. Option (c) is the correct choice because it accurately identifies this traditional whole-pathogen inactivation method.