Phase1 human trial of a COVID-19 vaccine called the Ad5-nCoV shows that it is safe, well-tolerated and able to generate an immune response against the SARS-CoV-2 in participants. The trial demonstrates that a single dose of the new vaccine produces virus-specific antibodies and T cells in 14 days, making it a potential candidate for further investigation.
The potential vaccine developed in China by CanSino Biologics was able to generate an immune response after an early trial in more than 100 people, according to a new study. The Ad5-nCoV uses a weakened version of a common cold virus (known as an adenovirus) which infects human cells but doesn't cause disease to deliver a fragment of genetic material from SARS-CoV-2, the virus that causes COVID-19. This genetic material provides instructions for making the "spike protein" on the surface of SARS-CoV-2. The idea is that a person's immune system will create antibodies against the spike protein, which will help fight off the coronavirus if the person is later exposed to it.
According to new research published in 'The Lancet', the open-label trial in 108 healthy adults, ages 18 to 60 demonstrates promising results after 28 days, the final results will be evaluated in six months. Further trials are needed to tell whether the immune response it elicits effectively protects against SARS-CoV-2 infection.
"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, making it a potential candidate for further investigation," says Professor Wei Chen from the Beijing Institute of Biotechnology in Beijing, China, who is responsible for the study. "However, these results should be interpreted cautiously. 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. 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 most common side effects of the vaccine were mild pain at the injection site, mild fever, fatigue, headache and muscle pain, the study said. Nine(9) participants (two in the low dose group, two in the middle dose group and five in the high dose group) developed a fever of more than 101 degrees Fahrenheit (38.5 degrees Celsius), and one participant in the high dose group developed a high fever along with fatigue, shortness of breath and muscle pain. The positive light is that these effects lasted no more than 48 hours.