Oxford Covid-19 vaccine 'works perfectly'; builds strong immunity to virus

Dubai - ChAdOx1 or AZD1222 is made by taking a common cold virus called an adenovirus from chimpanzees.

The AstraZeneca Covid-19 vaccine developed at Oxford University works perfectly and builds strong immunity to the virus, a study has shown.

The vaccine has been billed as one of the most promising in the world and has been shown to safely trigger an immune response in volunteers following early trials.

But, unlike traditional vaccines which use a weakened virus, or small amounts of it, the novel Oxford jab causes the body to make part of the virus itself.

Now researchers led by the University of Bristol have found this innovatve method works for the coronavirus, just as it has for similar viruses in the past.

According to the UK’s MailOnline, the study using cells in the laboratory found the vaccine effectively delivers the instructions for the Covid protein, which cells copy thousands of times to produce it in large amounts. This means a person's immune system is then primed to recognise the disease and fight it off without them falling ill.

Dr David Matthews, from Bristol's School of Cellular and Molecular Medicine (CMM), who led the research, said: “Until now, the technology hasn't been able to provide answers with such clarity, but we now know the vaccine is doing everything we expected and that is only good news in our fight against the illness.”

The first data from late-stage large-scale clinical trials being conducted in several countries around the world, including Brazil, the United States and Britain, are expected to be released before the end of the year.

The vaccine - known either as ChAdOx1 or AZD1222 - is made by taking a common cold virus called an adenovirus from chimpanzees and deleting about 20 per cent of the virus’s instructions. This means it is impossible for the vaccine to replicate or cause disease in humans.

The Bristol researchers’ focus was to assess how often and how accurately the vaccine is copying and using the genetic instructions programmed into it by its designers. These instructions detail how to make the spike protein from the coronavirus, SARS-CoV-2 that causes Covid-19.

Once the spike protein is made, the immune system reacts to it, training the immune system to identify a real Covid-19 infection.

"This is an important study as we are able to confirm that the genetic instructions underpinning this vaccine ... are correctly followed when they get into a human cell," Matthews said in a statement about the work.

His team's research was not peer reviewed by other scientists, but was published as a preprint before review.

Meanwhile, AstraZeneca has resumed the US trial of the experimental vaccine after approval by US regulators, the company said on Friday.

AstraZeneca's US trial was paused on September 6 after a report of a serious neurological illness, believed to be transverse myelitis, in a participant in the company's UK trial.

(With inputs from Reuters)

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