THE World Health Organisation (WHO) yesterday gave the green light to China’s CanSinoBio’s Covid-19 vaccine – the ninth shot to get the WHO seal of approval.

The single-shot Convidecia vaccine was granted emergency use listing (EUL) authorisation as China battles a resurgence of the virus triggered by Omicron.

It is the third Chinese-made vaccine to be approved by the United Nation’s health agency, after Sinovac and Sinopharm.

Convidecia was found to have 64% efficacy against symptomatic disease and 92% efficacy against severe Covid-19, said WHO.

“The vaccine meets WHO standards for protection against Covid-19 and… its benefits far outweigh risks,” said the agency in a statement.

WHO vaccine experts recommended it for people aged 18 and above.

Convidecia may be used as a booster dose following a completed primary series using any other EUL Covid-19 vaccine, said WHO.

Traditional vector method

The shot has already been rolled out in several countries, including China, Argentina, Chile, Malaysia, Mexico and Pakistan.

By the end of last year, more than 58 million people have been vaccinated with the vaccine, including almost 14 million in China, said WHO.

WHO has now given EUL status to nine Covid-19 vaccines and variations thereof – Pfizer/BioNTech, AstraZeneca, Janssen, Moderna, Sinovac, Sinopharm, Bharat Biotech, Novavax and CanSinoBio.

Convidecia is based on a modified human adenovirus. The AstraZeneca and Janssen vaccines are also both based on viral vector technology.

The more traditional approach uses a genetically-engineered version of common cold adenovirus as a “vector” to shuttle genetic instructions into human cells.

Convidecia “demonstrates a favourable safety profile in people across different age groups”, eliciting strong immune responses with both binding and neutralising antibodies, said WHO.

Stamp of approval

The EUL process studies the quality, safety and efficacy of vaccines and involves manufacturing site inspections.

WHO said such approval gives countries, funders, procuring agencies and communities assurance that the vaccine has met international standards.

WHO’s listing paves the way for countries to approve and import a vaccine for fast distribution, especially those without an international-standard regulator of their own.

It also opens the door for the shots to enter the Covax global vaccine-sharing facility, which aims to provide equitable access to doses around the world, particularly in poorer countries.

WHO began reviewing rolling data on the CanSinoBio vaccine in August.

Other vaccines are also on the path towards an EUL decision, with WHO studying rolling data on another Sinopharm shot, and vaccines from China’s Clover and Zhifei Longcom, France’s Sanofi and Iran’s Shifa Pharmed.

The EUL process on Russia’s Sputnik V jab has stalled.

Hundreds of candidate vaccines are being worked on in laboratories around the world. WHO is aware of 156 that have been in clinical development – tested on humans – and 198 that are in the pre-clinical phase. – AFP, May 20, 2022.