In the context of vaccines manufactured to prevent COVID-19 pandemic, consider the following statements:1.The Serum Institute of India produced COVID-19 vaccine named Covishield using mRNA platform.2.Sputnik V vaccine is manufactured using vector based platform.3.COVAXIN is an inactivated pathogen based vaccine.Which of the statements given above are correct?

1. A

   1 and 2 only

   1 and 2 only. Covishield is a viral-vector (ChAdOx1) vaccine, not mRNA.

2. B

   2 and 3 only

   2 and 3 only. Sputnik V is adenovirus-vector; Covaxin is inactivated whole-virion.

3. C

   1 and 3 only

   1 and 3 only. Statement 1 mislabels Covishield.

4. D

   1, 2 and 3

   All three. mRNA in India was (then) other platforms, not SII’s Covishield.

Summary. Official key is (b) 2 and 3 only. Covishield (SII) is chimpanzee adenovirus vector, not mRNA. Sputnik V is a heterologous adenovirus vector. Covaxin (BBV152) is inactivated SARS-CoV-2.