Oxford trial moves into next phase
LONDON: Days after reports suggested that a promising coronavirus disease (Covid-19) vaccine being developed by the Oxford Vaccine Group showed limited success on monkeys but could fail to prevent transmission of the virus, the developers of the vaccine at the University of Oxford described their efforts as progressing “very well”, moving to the next phase after completing 1,000 immunisations by its candidate-vaccine on healthy human adults.
The human trials were first initiated in April. The next phase, the second in the typical three phases of trials that a vaccine goes through, involves enrolling up to 10,260 adults and children to assess the immune response to the vaccine in people of different ages and assess if there is a variation.
The Oxford study is merging Phases II and III for a speedier development. Phase III involves assessing how the vaccine works in a large number of people over the age of 18, and how well it prevents people from becoming infected and unwell with Covid-19.
Andrew Pollard, head of the Oxford Vaccine Group, said in a
statement: “The clinical studies are progressing very well and we are now initiating studies to evaluate how well the vaccine induces immune responses in older adults, and to test whether it can provide protection in the wider population. We are very grateful to the huge support of the trial volunteers in helping test whether this new vaccine could protect humans against the pandemic coronavirus.”
Sarah Gilbert, professor of vaccinology at the Jenner Institute at Oxford University, added: “The Covid-19 vaccine trial team have been working hard on assessing the safety and immunogenicity of ChAdOx1 nCoV-19, and preparing to assess vaccine efficacy. We have had a lot of interest already from people over the age of 55 years who were not eligible to take part in the Phase I study, and we will now be able to include older age groups to continue the vaccine assessment.”
Adult participants in both the Phase II and Phase III groups will be randomised to receive one or two doses of either the ChAdOx1 nCoV-19 vaccine or a licensed vaccine (MenACWY) that will be used as a “control” for comparison. The experts said ChAdOx1 nCoV-19 is made from a virus (ChAdOx1) which is a weakened version of a common cold virus (adenovirus) that causes infections in chimpanzees, that has been genetically changed so that it is impossible for it to replicate in humans.
The university has tied up with biopharma major AstraZeneca to produce the vaccine on a mass scale, if the results are successful.
Earlier this week, results of the animal trials of the vaccine on pre-print server bioRxiv said that while the vaccine seemed to protect the monkeys from developing pneumonia, one of the conditions brought about by Covid-19 in people, it does not appear to stop them from being infected, nor prevent them from being transmitters.