The first Covid-19 vaccine to be tested in humans has been found to be safe, well-tolerated, and able to generate an immune response against the virus, according to new research published in The Lancet.
The Phase 1 trial, involving 108 healthy adults aged 18 to 60, showed promising results after 28 days, but final results will be evaluated in six months.
Further trials will also be needed to determine whether the immune response triggered by the vaccine effectively protects against the SARS-CoV-2 infection which causes Covid.
READ MORE: One in 20 Covid patients in hospital showed no symptoms of disease
"These results represent an important milestone," Professor Wei Chen, from the Beijing Institute of Biotechnology in China, who is responsible for the study.
However, he stressed that the results "should be interpreted cautiously".
"The challenges in the development of a Covid-19 vaccine are unprecedented, and the ability to trigger these immune responses does not necessarily indicate that the vaccine will protect humans from Covid-19.
"This result shows a promising vision for the development of Covid-19 vaccines, but we are still a long way from this vaccine being available to all.”
The creation of an effective vaccine is seen as vital to beating the pandemic.
Currently, there are more than 100 candidate Covid-19 vaccines in development worldwide.
The vaccine being trialled in China uses a de-activated adenovirus - one of the causes of the common cold - as a conduit to deliver genetic material to the cells that codes for SARS-CoV-2.
These cells then produce the virus' distinctive spike protein, and travel to the lymph nodes where the immune system creates antibodies that will be able to recognise that spike protein and fight off the coronavirus.
Volunteers were enrolled from one site in Wuhan, China, and assigned to receive either low, medium or high doses of the vaccine.
READ MORE: NHS staff in Glasgow asked to join Covid vaccine trial
The researchers tested the volunteers’ blood at regular intervals following vaccination to see whether the vaccine stimulated both antibody and T cell production - the two strands of human immune response.
It is thought that the ideal vaccine will be able to generate both antibody and T cell responses.
After 28 days, most participants had a four-fold increase in 'binding' antibodies, which that can attach to the coronavirus but do not necessarily attack it.
However, half to three-quarters of participants had developed neutralising antibodies, which do attack pathogens.
Importantly, the Ad5-nCoV vaccine also stimulated a rapid T-cell response in the majority of volunteers, which was greater in those given the higher and middle doses of vaccine.
T-cells are important because they are capable of recognising and destroying other cells in the body infected with the virus – not just the viral pathogen itself.
Further analyses showed that 28 days after vaccination, the majority of recipients showed either a positive T-cell response or had detectable neutralising antibodies.
However, the authors note that both the antibody and T-cell response could be reduced by high pre-existing immunity to adenovirus type 5.
A randomised, double-blinded, placebo-controlled Phase 2 trial of the Ad5-nCoV vaccine has now been initiated in Wuhan to determine whether the results can be replicated, and if there are any adverse events up to six months after vaccination.
It will involve 500 participants being given different doses of the vaccine or a placebo vaccine.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereLast Updated:
Report this comment Cancel