AstraZeneca/Oxford releases first COVID-19 vaccine candidate data; will seek EUA

Drug maker AstraZeneca said it will seek an emergency use authorization for its AZD1222 vaccine candidate for SARS-CoV-2 following positive high-level results from an interim analysis of ongoing clinical trials.

The vaccine, co-invented with researchers from the University of Oxford, has two dosing regimens. One, in which patients received a half dose, followed by a full dose a month later, was found to be 90% effective; a different dosing regimen, in which two full doses are administered a month apart, was 62% effective. Neither regimen resulted in serious safety events.

AZD1222 differs from two other leading vaccine candidates in that it 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.

AstraZeneca said that after vaccination, the surface spike protein is produced, priming the immune system to attack the SARS-CoV-2 virus if it later infects the body; protections from COVID-19 occur 14 day after the regimens’ conclusions. AZD1222 can be stored, transported and handled at normal refrigerated conditions (2-8 degrees Celsius/36-46 degrees Fahrenheit) for at least six months and administered within existing health care settings.

The drug maker expects to manufacture 3 billion doses by the end of 2021.