Oxford Vaccine Provoked T Cell Response Within 14 Days Of Vaccination

The results of the Phase I/II trial published on Monday in the scientific journal The Lancet, indicate no early safety concerns and induces strong immune responses in both parts of the immune system.

A team of scientists at Oxford University’s Jenner Institute and Oxford Vaccine Group have taken the next step towards the discovery of a safe, effective and accessible vaccine against coronavirus.

According to the University of Oxford, the vaccine provoked a T cell response within 14 days of vaccination (white blood cells that can attack cells infected with the SARS-CoV-2 virus), and an antibody response within 28 days (antibodies are able to neutralise the virus so that it cannot infect cells when initially contracted).

During the study participants who received the vaccine had detectable neutralising antibodies, which have been suggested by researchers as important for protection, and these responses were strongest after a booster dose, with 100% of participants’ blood having neutralising activity against the coronavirus. The next step in studying the vaccine is to confirm that it can effectively protect against SARS-CoV-2 infection.

The Phase I/II data for our coronavirus vaccine shows that the vaccine did not lead to any unexpected reactions and had a similar safety profile to previous vaccines of this type. 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, although we must continue with our rigorous clinical trial programme to confirm this in humans.

“We saw the strongest immune response in the 10 participants who received two doses of the vaccine, indicating that this might be a good strategy for vaccination,” Professor Pollard continues.

A UK Phase I/II trial began in April testing the Oxford coronavirus vaccine ChAdOx1 nCoV-19. The team started working to develop a vaccine against the global threat that is coronavirus in January 2020 and have been working with unprecedented urgency in a race against the coronavirus.

During the Phase I/II trial the vaccine has been evaluated in more than 1,000 healthy adult volunteers aged between 18 and 55 years in a randomised controlled trial. A subset of these volunteers (10 people) received two doses of the vaccine. Between April 23, 2020 and May 21, 2020, 1077 volunteers, received the vaccine ChAdOx1 nCoV-19 or a placebo MenACWY vaccine. There were no serious adverse health events related to ChAdOx1 nCoV-19.

These encouraging results support further evaluation of this candidate vaccine in our ongoing large scale Phase III programme, that is still needed to assess the ability of the vaccine to protect people from COVID-19

The University of Oxford is working with the UK-based global biopharmaceutical company AstraZeneca for the further development, large-scale manufacture and potential distribution of the Covid-19 vaccine, with plans for clinical development and production of the Oxford vaccine progressing globally. The project has been further spurred by £84 million of Government funding to help accelerate the vaccine’s development.

“We are encouraged by the Phase I/II interim data showing AZD1222 was capable of generating a rapid antibody and T-cell response against SARS-CoV-2. While there is more work to be done, today’s data increases our confidence that the vaccine will work and allows us to continue our plans to manufacture the vaccine at scale for broad and equitable access around the world,” says Mene Pangalos, Executive Vice President of BioPharmaceuticals Research and Development at AstraZeneca.