With reference to recent developments regarding ‘Recombinant Vector Vaccines’, consider the following statements : ​ 1. Genetic engineering is applied in the development of these vaccines. ​ 2. Bacteria and viruses are used as vectors. ​ Which of the statements given above is/are correct? ​

Both statements are correct, so the answer is C. A recombinant vector vaccine uses genetic engineering to take the gene for an antigen from a pathogen and insert it into a harmless carrier, the vector. The vector then presents that antigen to the immune system without causing disease.

• Statement 1 is correct: the whole design rests on recombinant DNA technology. The antigen gene is cloned into the vector genome, so genetic engineering is central to the vaccine, not incidental.
• Statement 2 is correct: vectors can be viral or bacterial. Examples include adenovirus-based platforms (ChAdOx1 and Ad26, used in COVID-19 vaccines), modified vaccinia Ankara, and attenuated Salmonella or Listeria strains explored as bacterial carriers.

Concept link: this sits under biotechnology and immunology in the Science and Technology section. For Mains GS-III, it helps in discussing vaccine platforms, biosafety and regulation of genetically modified carriers. The COVID-19 vaccines brought this platform into wide public use after the 2021 exam.

Trap: candidates who think only viruses serve as vectors pick option B, or assume a vaccine with a live carrier cannot involve genetic modification and pick option D. Both statements hold, so the answer is C.