ADENOVIRUS VACCINE

ADENOVIRUS VACCINE

Subject: Science & tech

Context: Unlike the mRNA vaccine platform used by Pfizer and Moderna, where vaccine efficacy reached 94% and 95%, respectively, the vector-based vaccine platform technology used by AstraZeneca and Johnson & Johnson have shown lower efficacy.

Concept:

Adenovirus Vector Vaccine :

• In this vaccine, adenovirus is used as a tool to deliver genes or vaccine antigens to the target host tissue.
• Adenovirus: Adenoviruses (ADVs) are DNA viruses ranging from 70-90 nanometre in size, which induce many illnesses in humans like cold, respiratory infection etc.
• Adenoviruses are preferred for vaccines because their DNA is double stranded which makes them genetically more stable and the chances of them changing after injection are lower.
• Rabies vaccine is an adenovirus vaccine.
• However, there are drawbacks of adenovirus vector vaccines like pre-existing immunity in humans, inflammatory responses etc.
• Just as human bodies develop immune responses to most real viral infections, they also develop immunity to adenoviral vectors.
• Since adenoviral vectors are based on natural viruses that some humans might already have been exposed to, these vaccines might not work for everyone.