China's COVID-19 vaccine trial shows promising results

COVID19 vaccine development and deployment in China, when available, will be made a global public good, as China's contribution to ensuring vaccine accessibility and affordability in developing countries.

——President Xi Jinping made the announcement during a speech at a virtual event opening the 73^rd session of the World Health Assembly

China's COVID-19 vaccine trial, the first such vaccine to reach phase 1 clinical trial, has been found to be safe, well-tolerated, and able to generate an immune response against SARS-CoV-2 in humans, according to a study published online on May 22 by the medical journal The Lancet.

The vaccine, classified as "recombinant adenovirus type-5 vectored" (Ad5-nCoV), acts as a natural infection and is especially good at teaching the immune system how to fight the virus.

The open-label trial in 108 healthy adults demonstrates promising results after 28 days and the final results will be evaluated in six months, The Lancet said in a press statement.

Further trials are needed to tell whether the immune response it elicits effectively protects against SARS-CoV-2 infection, said the medical journal.

"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," said 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 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," said Chen.

A randomized, double-blinded, placebo-controlled phase 2 trial of the Ad5-nCoV vaccine has been initiated in the central Chinese city of Wuhan to determine whether the results can be replicated, and if there are any adverse events up to six months after vaccination, in 500 healthy adults-250 volunteers given a middle dose, 125 given a low dose, and 125 given a placebo as a control, according to The Lancet. (Edited from CGTN, Xinhua, China Daily)

Further reading: China now has five vaccines, one vector and four inactivated, that have entered the first two phases of clinical trials in China. Vaccine recipients in phase II trials have reported no major adverse effects, and these vaccines are set to complete their phase II trials in July.