AstraZeneca has reached an agreement with Europe’s Inclusive Vaccines Alliance (IVA), spearheaded by Germany, France, Italy and the Netherlands, to supply up to 400 million doses of the University of Oxford’s Covid-19 vaccine, with deliveries starting by the end of 2020.

Oxford University last month announced the start of a Phase II/III UK trial of the vaccine, AZD1222, in about 10,000 adult volunteers. Other late-stage trials are due to begin in a number of countries. AstraZeneca (AZ) says it “recognises that the vaccine may not work but is committed to progressing the clinical programme with speed and scaling up manufacturing at risk”.

AZD1222 has been developed by Oxford University’s Jenner Institute, working with the Oxford Vaccine Group. It uses a replication-deficient viral vector based on a weakened version of a common cold (adenovirus) virus that causes infections in chimpanzees, and contains the genetic material of SARS-CoV-2 spike protein. After vaccination, the surface spike protein is produced, priming the body's immune system to attack Covid-19 if it later infects the body.

The recombinant adenovirus vector (ChAdOx1) was chosen to generate a strong immune response from a single dose. It is not replicating, so cannot cause an ongoing infection in the vaccinated individual.

Vaccines made from the ChAdOx1 virus have been given to more than 320 people to date and have been shown to be well tolerated, although they can cause temporary side effects such as a temperature, influenza-like symptoms, headache or a sore arm. AZ chief executive Pascal Soriot has said the potential vaccine is likely to provide protection against contracting Covid-19 for about a year.

AZ is building a number of supply chains across the world, including Europe, and is seeking to expand manufacturing capacity further. It says it is open to collaborating with other companies in order to meet its commitment to support access to the vaccine at no profit during the pandemic.

The company has recently completed supply agreements with the UK, US, the Coalition for Epidemic Preparedness Innovations and Gavi, the Vaccine Alliance, for 700 million doses, and it agreed a licence with the Serum Institute of India for the supply of an additional one billion doses, principally for low- and middle-income countries. Total manufacturing capacity currently stands at two billion doses.