With reference to recent developments regarding 'Recombinant Vector Vaccine', consider the following statements:1.Genetic engineering is applied in the development

1. A

   1 only

   1 only. Viral vectors are also in the definition.

2. B

   2 only

   2 only. Genetic engineering is also applied.

3. C

   Both 1 and 2

   Both. Recombinant vector vaccines are genetically engineered; viruses (adenovirus and others) are used as vectors.

4. D

   Neither 1 nor 2

   Neither. Both limbs hold.

Summary. Official key is (c) both. A recombinant vector vaccine uses genetic engineering and a harmless virus (or bacterium) to carry antigen genes — the COVID adenovirus shots are the classroom example.