The UK became the first country to approve the AstraZeneca-Oxford covid vaccine, on Wednesday, 30 December 2020. Today, Brian Pinker, 82, became the first person in the world, outside clinical trials, to receive the initial dose of the AZD1222 vaccine.
The AZD1222 vaccine uses an adenovirus that infects only chimpanzees as the viral vector. Because immunity against chimp adenovirus is extremely rare in humans, it is unlikely that the body will start an immune response against the viral vector itself.
After vaccination, the vaccine vector enters the cells, which will start to produce the spike protein, prompting the immune system to react against it. If the vaccinated person later comes in contact with Sars-CoV2, their immune system is triggered to fight the virus.
Like Pfizer’s and Moderna’s vaccines, the AZD1222 vaccine is to be administered in two doses. After the preliminary results showed unclear efficacy numbers, final reports suggest an overall efficacy of 70%.
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