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Coronavirus vaccine results demonstrate strong immune response

Published: 21 July 2020


The Oxford coronavirus vaccine, tested by researchers and clinicians at St George’s, University of London and St George’s University Hospitals NHS Foundation Trust, is a step closer to being considered a safe, effective and accessible vaccine against coronavirus.

The results of the Phase I/II trial published yesterday in The Lancet, indicate no early safety concerns and that the vaccine induces strong immune responses in both parts of the immune system.

During the Phase I/II trial, the vaccine was evaluated in more than 1,000 healthy adult volunteers aged between 18 and 55 years. A total of 469 participants have been recruited by St George’s so far in the development of the vaccine.

In the latest results, the vaccine provoked a peak T cell response within 14 days of vaccination (white blood cells that can attack cells infected with the SARS-CoV-2 virus), and a peak antibody response within 28 days (antibodies that can neutralise the virus so that it cannot infect cells). Neutralising antibodies are believed to be key to protection. The study results also showed no serious adverse health events related to the coronavirus vaccine.

Ten of the volunteers received two doses of the vaccine. The antibody responses were even stronger after the booster dose.  

Professor Andrew Pollard, Chief investigator of the Oxford Vaccine Trial at Oxford University and co-author of the study, said: “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.”

The next step in studying the vaccine is to confirm that it can effectively protect against COVID-19 infection in a larger phase III trial.

Professor Paul Heath, Director of the Vaccine Institute at St George’s, University of London and co-author of the study, said: “We are delighted to have contributed to this important first phase of the vaccine trial. The phase III trial in which we are also participating will provide the critical information needed to show whether this vaccine can effectively protect against COVID-19.”

This trial forms part of a portfolio of research at St George’s to tackle the coronavirus pandemic. The University has launched a Coronavirus Action Fund to raise money for vital research into the pandemic and is actively seeking support for a broad research programme involving all parts of the University. 

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