Dr Bruno Hoen is director of medical research at prestigious Paris centre l’Institut Pasteur.
He spoke to news service FranceInfo to comment on the announcement in medical journal The Lancet yesterday (Monday July 20) that a vaccine trial at the University of Oxford in the UK (with pharmaceutical company AstraZeneca) had “triggered an immune response”.
This means that the vaccine - called ChAdOx1 nCoV-19 or AZD1222 - appears to be safe and produces few serious side effects, as well as causing the body to make antibodies and T-cells (a type of white blood cell) that could fight the virus.
Another trial in China, supported by CanSino Biologics, has also suggested similar results. These have been described as “promising” and “hopeful”.
Yet, the trials are continuing, and current success does not mean that the vaccine will definitely be safe or effective enough for general use any time soon, Dr Hoen has said.
Dr Hoen explained: “These are two trials in what we call ‘Phase 2’, meaning that they are evaluating the safety and immune response of two vaccinations that are relatively comparable in construction, as they are two viral vaccinations.
“These two trials show that on the one hand, the vaccinations are well tolerated [by the body]. There are no serious side effects. And...that there is an immune response. But that does not mean, for the moment, that the vaccinations will offer protection.
“We are waiting for these trials to begin ‘Phase 3’, which will allow us to answer this question.”
‘Promising results’ but ‘more work to do’
As the results were announced yesterday, Professor Andrew Pollard, from the Oxford research group, told the BBC: "We're really pleased with the results published today as we're seeing both neutralising antibodies and T-cells.
"They're extremely promising and we believe the type of response that may be associated with protection. But the key question everyone wants to know is: does the vaccine work? does it offer protection?... and we're in a waiting game."
Dr Sarah Gilbert, vaccination researcher at Oxford University, said: “There is still a lot of work to do before we can confirm if our vaccine will help to manage the Covid-19 pandemic, but these early results are promising.”
Dr Hoen added: “There are several arguments to suggest that there is a good chance that they will offer protection because the antibodies identified in vaccinated patients are such that - for a lot of them - have the capacity to neutralise the virus. Which is hopeful.”
Trials are set to begin in “areas where the virus is spreading”, he said.
Commenting on the “vaccination race” currently taking place between several laboratories, Dr Hoen continued: “The planned model for the development of making these vaccinations available - once we have one, and I hope, several effective ones - will be funded internationally.
“We will have to choose between the effective vaccinations - which will be easier to produce in a large quantity, at a low cost.”
But Dr Hoen said that this would “not be in 2020, and if [we manage it] in 2021, that will be a major feat.”
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