MALAYSIA recently took delivery of its first single-dose vaccine from CanSino Biologics Inc, adding to its range of hitherto only double-dose vaccines

Putrajaya had previously said that single-dose vaccines – CanSino and Johnson & Johnson – are likely to be administered in areas that are not easily accessible.

Science, Innovation and Technology Minister Dr Adham Baba recently said CanSino would be used along with the Sinovac vaccine to boost vaccination coverage in states that have yet to inoculate at least 50% of its population.

“CanSino can be used in areas that are difficult to reach,” he said.

Adham said Malaysia has purchased 3.5 million doses of the CanSino vaccine.

Three million doses of these will be locally filled and finished by Solution Biologics Sdn Bhd (SolBio).

The remaining 500,000 doses of the finished product will be received in bulk from CanSino China.

Malaysia received its first batch of the CanSino vaccine consisting of 200,000 doses from Beijing, China on August 20.

According to findings of phase 3 clinical trials, the Convidecia Recombinant Novel Coronavirus Vaccine (Adenovirus Type 5 Vector) produced by China-based CanSino Biologics is said to have an efficacy rate of 65.28% in preventing symptomatic Covid-19 cases.

Phase 3 clinical trials were carried out in Pakistan, Russia, Mexico and Chile.

Booster shots

The CanSino jab works in a way that is similar to the AstraZeneca vaccine.

A weakened common cold virus, known as adenovirus, is used to bring non-replicable surface proteins of the SARS-CoV-2 pathogen to the cells to trigger an immune response.

However, CanSinoBIO chief scientific officer Zhu Tao reportedly said on April 1, that the vaccine’s efficacy could drop over time.

He said the vaccine should have at least 50% efficacy five to six months after the jab.

Zhu also floated the idea that a booster shot might be required, although more clinical trial data is needed to determine this.

“A booster shot six months later led to a seven times to 10 times increase in neutralising antibody levels, so we expect in this case efficacy could reach over 90%,” Reuters quoted him as saying in April.

In another Reuters report in August, Zhu was quoted as saying that the efficacy could drop by as much as around 30% after six months.

He also noted that the antibody level could increase by eight-fold with a second shot after vaccination.

Unlike its double-dose counterparts, which take 14 days to develop protection, a recipient of the CanSino vaccine is considered fully vaccinated after 28 days.

The vaccine is also cheaper in terms of logistics and storage as it does not require storage in extremely low temperatures and can be refrigerated at a temperature of 2°C to 8°C.

Pierre Morgon, senior vice-president at the Hong Kong-listed CanSinoBIO said the firm was looking to pair the vaccine with the Sputnik V vaccine produced by the Russian Gamaleya Research Institute in an upcoming clinical trial.

CanSino was also the first in the world to start clinical trials on humans. The first person on record to receive the jab was Dr Chen Wei, a virologist and major-general in China’s People’s Liberation Army.

Having received the jab on February 29, 2020, she was also one of the first people on earth to receive a Covid-19 shot.

In June last year, a month after the company published the first peer-reviewed phase 1 clinical trial data, the vaccine was approved for use on Chinese soldiers.

Currently, the Pfizer, AstraZeneca and Sinovac double-dose vaccines are used in the national Covid-19 immunisation programme in Malaysia.

The government has also applied for the single-dose vaccine from Johnson & Johnson via Covax .

Covax, or the Covid-19 vaccine global access platform, is coordinated by the Global Alliance for Vaccines and Immunisation, the Coalition for Epidemic Preparedness, and the World Health Organization, with Unicef as the key delivery partner. – September 3, 2021.