Results from the Phase I/II trials for ChAdOx1 nCoV-19, the vaccine developed by scientists at The University of Oxford’s Jenner Institute and the Oxford Vaccine group, have been published today in scientific journal, The Lancet.
The results show that the vaccine induces a strong response in the participants and had no concerning side effects. Professor Andrew Pollard said, “the vaccine did not lead to any unexpected reactions and had a similar safety profile to previous vaccines of this type,” based on Phase I/II data, remarking, “the vaccine really does perform in exactly the same way as we’ve seen with other vaccines of this type.” The vaccine induced the common side effects of fever and/or a headache in 70% of participants, but researchers commented that this can be managed with paracetamol.
From the data published today, the vaccine invokes both a strong antibody and T-cell response in humans. T cells produced in response to the vaccine will recognise and destroy the SARS-CoV-2 virus, while antibodies will find and neutralise virus cells to prevent further infection of the body’s cells after a person has first contracted coronavirus. Phase I/II data has shown that the vaccine activates T cells within 14 days of vaccination, while antibodies are produced within 28 days, suggesting that this vaccine holds great promise.
The UK Phase I/II trial started in early April 2020, with 1,077 healthy adult volunteers receiving vaccination in a randomised controlled trial with the ChAdOx1 nCoV-19 vaccine and a MenACWY vaccine placebo, with 90% of volunteers showing neutralising activity in the blood. 10 participants also received a second dose of the vaccine and results from these volunteers showed the strongest levels of immune response with 100% neutralising activity in the blood, showing that a booster dose could be effective in improving protection against SARS-CoV-2 virus.
The team at Oxford have been working since January 2020 to find a vaccine for Covid-19, with more than 10,000 people in the UK so far recruited into the trials. Phase III trials have also begun in other countries such as the US, South Africa, and Brazil. The team has partnered with AstraZeneca in April for manufacture, with around 100 million doses of the vaccine set to be produced for the UK. The UK government has struck deals with the BioNTech/Pfizer alliance and Valneva for early access to a total of 90 million vaccine doses.
What’s next for the vaccine?
Professor Sarah Gilbert remarked that the process has been “both exhausting and exhilarating”, saying “there is still much work to be done before we can confirm if our vaccine will help manage the Covid-19 pandemic, but these early results hold promise.“
Now the vaccine has demonstrated a good immune response and has no significant side effects, the next steps are to ensure that the vaccine can effectively prevent infection of SARS-CoV-2 infection in humans, by determining whether a booster dose is necessary, the dose of the vaccine required and whether the dose of the vaccine needs to be higher in those who are vulnerable and elderly.
Alok Sharma, Business Secretary, commented, “Today’s results are extremely encouraging, taking us one step closer to finding a successful vaccine to protect millions in the UK and across the world. Backed by £84 million Government investment for the vaccine’s development and manufacture, the agility and speed with which the University of Oxford have been working is outstanding. I am very proud of what they have achieved so far.”
Layla Moran, Lib Dem MP for Oxford West and Abingdon, said, “On behalf of our whole community, I’m incredibly proud that Oxford’s COVID-19 vaccine has passed crucial trials. I know we’re not there yet, but the signs are really promising.”
The full study from the Oxford COVID Vaccine Trial Group can be found here.