The first findings from a human trial to develop a coronavirus vaccine have shown it is safe and induces a “strong” immune reaction.
The results of tests carried out by Oxford University were published on Monday in The Lancet medical journal.
The journal said: “Authors say further clinical studies, including in older adults, should be done with this vaccine.”
However, it warned of the trial, which had 1,077 participants aged between 18 and 55: “Current results focus on immune response measured in the laboratory. Further testing is needed to confirm if [the] vaccine effectively protects against infection.”
Boris Johnson, while sounding caution, said it was an “important step in the right direction”.
The early stage trial found that the vaccine is safe and causes few side effects.
It also induces strong immune responses in both parts of the immune system, provoking a T cell response within 14 days of vaccination, and an antibody response within 28 days.
Compared with the control group of those given a meningitis vaccine, the COVID-19 vaccine caused minor side effects more frequently, according to the study.
But some of these could be reduced by taking paracetamol, the researchers said, adding that there were no serious adverse events from the vaccine.
The university’s Prof Sarah Gilbert, who was co-author of the study, said: “There is still much work to be done before we can confirm if our vaccine will help manage the COVID-19 pandemic, but these early results hold promise.
“As well as continuing to test our vaccine in phase-three trials, we need to learn more about the virus – for example, we still do not know how strong an immune response we need to provoke to effectively protect against Sars-Cov-2 infection.
“If our vaccine is effective, it is a promising option as these types of vaccine can be manufactured at large scale.
“A successful vaccine against Sars-Cov-2 could be used to prevent infection, disease and death in the whole population, with high-risk populations such as hospital workers and older adults prioritised to receive vaccination.”
Governments around the world are keenly following the results of numerous vaccine trials in a bid to stem the pandemic.
Responding to the news, Johnson said:
Earlier on Monday, Johnson said he could not be “100% confident” a vaccine would be available this year or next year.
“Obviously I’m hopeful, I’ve got my fingers crossed, but to say that I’m 100% confident that we will get a vaccine this year – or indeed next year – is, alas, just an exaggeration. We are not there yet.
“It may be that the vaccine is going to come riding over the hill like the cavalry, but we just can’t count on it right now.”
On Monday, Kate Bingham, the chair of the government’s vaccine taskforce, said she was hopeful a vaccine could be available by the end of this year.