Russia two-shot Covid-19 vaccine 
--------------------------------------
Russia’s “Sputnik-V” vaccine produced an antibody response in all 76 participants in two small phase 1/2 trials. The so-called viral vector vaccine has now started a 40,000-strong phase 3 trial
--------------------------------------
Adenovirus
Vector: Harmless virus that lacks gene responsible for replication in human host cell. Vaccine uses two adenovirus vectors – AD26 and AD5 – to carry coronavirus gene to trigger immune response
Spike protein gene: Cut from Sars-CoV-2 genome...
...and inserted into each vector Genome
--------------------------------------
Sars-CoV-2 coronavirus
Spike glycoprotein: Virus uses protein to enter human cell to replicate

AD26 Vector 1
AD5 Vector 2

Phase 1/2 trials: Between June 18 and August 3, two groups of 38 healthy volunteers were injected with vector 1, followed by vector 2 three weeks later

Human Antibodies cell

Vaccine induced spike protein antigen which triggered strong antibody immune response in all 76 participants
--------------------------------------
Sources: The Lancet, Gamaleya Research Institute, sputnikvaccine.com © GRAPHIC NEWS