According to new studies published in The Lancet, it was found that the first COVID-19 vaccine, which reached Phase 1 of a clinical trial, is safe, well-tolerated, and able to quickly generate an immune response against SARS-CoV-2 in humans.
The study was conducted on 108 healthy adults, and it shows promising results 28 days after administration, the final results will be evaluated after six months. Further tests are needed to determine if the immune response that the SARS-CoV-2 vaccine evokes is effective.
“These results represent an important milestone. The test shows that a single dose of the new COVID-19 type 5 adovirus vaccine (Ad5-nCoV) produces virus-specific antibodies and T cells for 14 days, making it a potential candidate for further study. However, these results should be interpreted with caution. The challenges in developing a vaccine against COVD-19 are unprecedented, and the ability to elicit these immune responses does not necessarily indicate that the vaccine will protect people from COVID-19. This result shows a promising vision for the development of vaccines against COVID-19, but we are still far from making this vaccine available to everyone”.
Wei Chen from Beijing Institute of Biotechnology in Beijing, China.
Creating an effective vaccine is seen as a long-term solution to the COVID-19 pandemic. Currently, more than 100 candidate vaccines against COVID-19 are being developed in the world.
The new Ad5 vaccine for COVID-19, evaluated in this trial, is the first to be tested in humans. It uses a weakened cold virus (an adenovirus that easily infects human cells but is not able to cause disease) to deliver the genetic material that encodes the spike SARS-CoV-2 protein to the cells. These cells then produce the spike protein and travel to the lymph nodes, where the immune system creates antibodies that recognize this spike protein and fight the coronavirus.
Volunteers aged 18 to 60 were from Wuhan, China. They were not affected by coronavirus infection. The vaccine candidate was well tolerated in all doses, and no serious side effects were reported within 28 days after vaccination. Most adverse events were mild or moderate.
The most common adverse reactions were mild pain at the injection site, which was reported in more than half, fever, fatigue, headache, and muscle pain. One participant who received a higher dose of the vaccine reported severe fever along with severe symptoms of fatigue, shortness of breath, and muscle pain – however, these adverse reactions persisted for less than 48 hours.
A randomized, double-blind, placebo-controlled phase 2 trial of the Ad5-nCoV vaccine was started in Wuhan to determine if the results could be repeated and if there were any side effects within 6 months after vaccination. For the first time, it will include participants over 60 who are an important target group for the vaccine.