Introduction of AZD1222
AstraZeneca known as AZD1222 was co-invented by the University of Oxford and its spin-out company.
AZD1222 uses a replication-deficient chimpanzee viral vector based on a weakened version of a common cold virus (adenovirus) that causes infections in chimpanzees and contains the genetic material of the SARS-CoV-2 virus spike protein.
Coronavirus Infection and Immune Response
Quick facts for ChAdOx- 1 vaccine platform
Adenoviruses are common viruses that typically cause mild cold- or flu- like illness. Adenoviruses can cause illness in people of all ages any time of year.
Adenoviruses as a vector or vehicle has been under study since 1990.
Chimpanzee Adenoviruses ChAdOx-1 is patented by Vaccitech a clinical stage company.
ChAdOx-1 platform has been used in MERS, SARS, Malaria, TB, Influenza, Chikungunya etc. and found to be safe and induce CD8 & CD4 immune response.
Live attenuated vaccine weakened virus
Added value of this Study
The results of the first clinical study of ChAdOx1 nCoV-19 (AZD1222). The vaccine was safe and tolerated, with reduced reactogenicity when paracetamol was used prophylactically for the first 24 h after vaccination. Reactogenicity was reduced after a second dose. Humoral responses to SARS-CoV-2 spike protein peaked by day 28 post prime and cellular responses were induced in all participants by day 14.
Neutralising antibodies were induced in all participants after a second vaccine dose. After two doses, potent cellular and humoral immunogenicity was present in all participants studied.
Implications of all the Available Evidence
A vaccine against SARSCoV-2 could be used to prevent infection, disease, and death in the global population, with high-risk populations such as hospital workers and older adults (eg, ≥65 years of age) prioritized to receive vaccination.