How do COVID vaccines stimulate an immune response?
- ABy introducing live attenuated SARS-CoV-2 virus
- BBy introducing a real SARS-CoV-2 virus
- CBy introducing a harmless piece of SARS-CoV-2 virus
- DBy introducing antibodies against SARS-CoV-2 virus
Show answer and explanation
Correct answers: (a) By introducing live attenuated SARS-CoV-2 virus or (c) By introducing a harmless piece of SARS-CoV-2 virus
Explanation
Most COVID vaccines give the body a harmless piece of SARS-CoV-2, the spike protein (Novavax, Corbevax), or the genetic instructions to make it (mRNA vaccines such as Moderna, vector vaccines such as Covishield): option (c).
Covaxin and Sinovac use a whole inactivated (killed) virus, and no vaccine in wide use was live attenuated. The Commission’s key is option (a), so both (a) and (c) are accepted here.
Either way, the immune system learns to recognise the virus and makes antibodies before a real infection.