Study finds Oxford's coronavirus vaccine 'safe, immunogenic'

A vaccine candidate developed at the University of Oxford has shown encouraging results in early human testing and appears to be "safe well-tolerated, and immunogenic", the findings of the trial published in The Lancet journal said.

Trials involving 1,077 people showed the injection led to them making antibodies and white blood cells that can fight coronavirus.

"Our preliminary findings show that the candidate ChAdOx1 nCoV-19 vaccine given as a single dose was safe and tolerated, despite a higher reactogenicity profile than the control vaccine, MenACWY," the researchers, led by Pedro M Folegatti and Katiet Ewer, wrote in the study. 

"No serious adverse reactions to ChAdOx1 nCoV-19 occurred. The majority of adverse events reported were mild or moderate in severity, and all were self-limiting," the study said. 

The clinical trials of the potential COVID-19 vaccine on humans was conducted between April 23 and May 21. 

The Oxford vaccine -- called ChAdOx1 nCoV-19 -- is made from a harmless chimpanzee virus. The human vaccine trial has been developed by scientists at Oxford University`s Jenner Institute.

According to the findings of the study, 1077 participants were enrolled and assigned to receive either ChAdOx1 nCoV-19, 10 of whom were enrolled in the non-randomised ChAdOx1 nCoV-19 prime-boost group. 

"Local and systemic reactions were more common in the ChAdOx1 nCoV-19 group and many were reduced by use of prophylactic paracetamol, including pain, feeling feverish, chills, muscle ache, headache, and malaise). There were no serious adverse events related to ChAdOx1 nCoV-19. In the ChAdOx1 nCoV-19 group, spike-specific T-cell responses peaked on day 14. Anti-spike IgG responses rose by day 28, and were boosted following a second dose," the study said. 

"Neutralising antibody responses against SARS-CoV-2 were detected in 32 (91%) of 35 participants after a single dose when measured in MNA80 and in 35 (100%) participants when measured in PRNT50. After a booster dose, all participants had neutralising activity (nine of nine in MNA80 at day 42 and ten of ten in Marburg VN on day 56). Neutralising antibody responses correlated strongly with antibody levels measured by ELISA," it added. 

ChAdOx1 nCoV-19 showed an acceptable safety profile, and homologous boosting increased antibody responses, it said. 

Oxford’s Covid-19 vaccine produces a good immune response, reveals new study.
Teams at @VaccineTrials and @OxfordVacGroup have found there were no safety concerns, and the vaccine stimulated strong immune responses: https://t.co/krqRzXMh7B pic.twitter.com/Svd3MhCXWZ

— University of Oxford (@UniofOxford) July 20, 2020

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), the university said in a press release.

These results, together with the induction of both humoral and cellular immune responses, support largescale evaluation of this candidate vaccine in an ongoing phase 3 programme, the study said in its findings. 

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.

The next step in studying the vaccine is to confirm that it can effectively protect against SARS-CoV-2 infection.

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.