The World Health Organisation has approved a single dose Covid-19 vaccine from China’s CanSino Biologics, for emergency use. This takes the number of WHO-validated Covid-19 vaccines approved for emergency use to 11.
The Emergency Use Listing (EUL) procedure assesses the quality, safety and efficacy of these vaccines, as a prerequisite to be part of its COVAX vaccine supply. The procedure also helps countries who do not have an elaborate regulatory system to import and administer these vaccines.
A single dose for all age groups
CONVIDECIA (the CanSino vaccine) is based on a modified human adenovirus that expresses the spike S protein of SARS-CoV-2. WHO’s Strategic Advisory Group of Experts on Immunization (SAGE) has recommended the vaccine as a single (0.5 ml) dose, in all age groups 18 and above. CONVIDECIA was found to have 64 per cent efficacy against symptomatic disease and 92 per cent efficicay against severe Covid-19, a note from WHO said.
CanSino’s vaccine joins a list including those from Pfizer-BioNTech, AstraZeneca-OxfordUniversity, Serum Institute for Covishield (the AZ-Oxford vaccine) Moderna, Johnson & Johnson, Sinopharm, Sinovac, Bharat Biotech (though supplies are currently suspended to UN procurement agencies), Novavax and Serum Institute for Covovax (Novavax’s vaccine).
Clinical trial data
The EUL procedure assesses the suitability of novel health products during public health emergencies. The objective is to make medicines, vaccines and diagnostics available as rapidly as possible to address an emergency while adhering to stringent criteria on safety, efficacy and quality, the WHO said. “The assessment weighs the threat posed by the emergency as well as the benefit that would accrue from the use of the product against any potential risks.”
The pathway involves a rigorous assessment of late phase-II and phase-III clinical trial data as well as substantial additional data on safety, efficacy, quality and a risk management plan. This data is reviewed by independent experts and WHO teams, who consider the current body of evidence on the vaccine under consideration, the plans for monitoring its use, and plans for further studies, the UN health agency explained.
As part of the EUL process, the company producing the vaccine must commit to continue to generate data to enable full licensure and WHO pre-qualification of the vaccine, it added.