The first COVID-19 vaccine to reach phase I clinical trial is safe, well-tolerated, and capable of generating an immune response against the novel coronavirus in humans, says a new research published in The Lancet journal.
According to the study of 108 adults, the vaccine produced neutralising antibodies, and a response mediated by the immune system’s T-cells against the novel coronavirus, SARS-CoV-2.
However, the scientists, including those from the Beijing Institute of Biotechnology in China said further research is needed to confirm whether the vaccine protects against SARS-COV-2 infection.
In the trial, carried out in 108 healthy adults, the vaccine demonstrated promising results after 28 days, with the final results to be evaluated in six months, the study said.
“These results represent an important milestone. The trial demonstrates that a single dose of the new adenovirus type 5 vectored COVID-19 (Ad5-nCoV) vaccine produces virus-specific antibodies and T cells in 14 days,” said study co-author Wei Chen from the Beijing Institute of Biotechnology.
Based on the results, Chen said the vaccine is a potential candidate for further investigation.
However, the researchers cautioned that the results should be interpreted carefully.
“The challenges in the development of a COVD-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,” Chen explained.
The Ad5 vectored COVID-19 vaccine used in the trial is the first to be tested in humans, the scientists said.
It uses a weakened common cold-causing adenovirus — which infects human cells readily, but is incapable of causing disease — to deliver genetic material that codes for the SARS-CoV-2 spike protein to the cells, the study noted.
The scientists said these cells then produce the spike protein, and travel to the lymph nodes where the immune system creates antibodies.
These then recognise the spike protein and fight off the coronavirus, the researchers explained.