CanSino Biologics has become one of the first companies to receive preliminary approval for its COVID-19 vaccine in China, marking a major milestone in the unprecedented fight against the coronavirus pandemic.
China’s decision to give CanSino’s vaccine, Ad5-nCOV, a greenlight for use in the Chinese military has warranted international attention. What should we know about this vaccine and its implications in the race to develop a safe, widely accepted vaccine?
All About CanSino and Ad5-nCOV
On June 30, 2020, the Chinese government in Beijing approved the use of CanSino’s experimental Ad5-nCOV vaccine for the country’s military for a period of one year.
“The Ad5-nCoV is currently limited to military use only and its use cannot be expanded to a broader vaccination range without the approval of the Logistics Support Department,” CanSino said, referring to the Central Military Commission department which approved the military use of the vaccine.
At the time of approval, the experimental vaccine is still undergoing Phase 1 and 2 clinical trials. Existing data suggests Ad5-nCOV has the potential to prevent disease caused by the coronavirus, but commercial success is not yet guaranteed.
Ad5-nCOV is far from the only vaccine currently under development by CanSino. The company has 16 active vaccine candidates. It conducts the majority of its development operations in partnership with public institutions in China, such as universities, the military, and biotech companies.
How Does Ad5-nCOV Vaccine Candidate Work?
CanSino’s COVID-19 candidate is based on an adenoviral vector. Researchers genetically engineered harmless adenoviruses to express a specific coronavirus protein. The immune system recognizes that protein and can respond accordingly.
Since the vector used in this vaccine candidate is a viral particle, it may be able to trigger a more efficient immune system response than a standard vaccine. If so, Ad5-nCOV could prove to produce longer-lasting and more effective immunity.
Current research demonstrates that Ad4-nCOV is tolerable and immunogenetic at 28 days post-vaccination. “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.
The Future of Ad5-nCOV
On May 16, Health Canada approved human clinical trials for CanSino’s experimental vaccine. Prime Minister Justin Trudeau announced the first Canadian clinical trials will be conducted from the Canadian Centre for Vaccinology at Dalhousie University.
Only a few days earlier, the National Research Council of Canada announced its own collaboration with CanSino Biologics to advance clinical development of the potential vaccine- and many others- in Canada.
Meanwhile, back in China, a new randomized, double-blinded, placebo-controlled Phase 2 clinical trial just began in Wuhan to determine whether the results of the most recent Ad5-nCOV study can be replicated. This study will also study adverse events up to six months after vaccination in 500 healthy adults.