The University of Oxford’s ChAdOx1 nCoV-19 is the world-leading vaccine candidate, according to the Chief Scientist of the World Health Organisation. Phase 1 trial results released earlier today suggest that the vaccine is “safe, tolerated and immunogenic”. It may also offer “double protection” against the deadly virus.
The British-Swedish pharmaceutical giant AstraZeneza is helping developing the vaccine, which uses a weakened form of chimpanzee adenovirus . Phase 1 trials – which aim to assess the vaccine’s safety, began in April with more than 1000 inoculations. Results published in The Lancet show that a single dose of the candidate induced the production of neutralising antibodies, as well as spike-specific ‘killer’ T-cells. These findings could represent an unprecedented breakthrough in vaccine progress. While neutralising antibodies can render the virus noninfectious, they tend to fade after a short period. On the other hand, T cells can circulate in the blood for years, directly destroying infected human cells.
Professor Andrew Pollard, Chief investigator of the trial said: “The immune responses observed following vaccination are in line with what previous animal studies have shown are associated with protection against the SARS-CoV-2 virus.” The vaccine also fared well in terms of safety. No severe adverse reactions were observed; mild to moderate side effects included fatigue and headache. So, when can we expect a vaccine?
According to the director of the Jenner Institute, Adrian Hill, we could potentially see a vaccine this year – if multiple trials prove it can protect against infection. The project has the backing of a £65.5 million investment from the government, as well as funding from the US. AstraZeneca predicts that manufacturing each dose will cost “about as much as a cup of coffee.” Nonetheless, these results do not yet prove that the vaccine can prevent infection and provide long-lasting immunity for all individuals. Ongoing trials have focused on young, healthy and predominantly white volunteers. Further studies in older, less healthy and more diverse populations are required. With this in mind, Phase 3 trials are currently running in Brazil and South Africa, alongside national testing.
Construction of the UK’s first Vaccines Manufacturing Innovation Centre is well underway, and production is expected to start in 2021. It is hoped that enough vaccines for the whole population could be created within 6 months.