As many as 20,000 Mexican citizens have volunteered to take part in clinical trials for the CanSino Biologics Inc. Covid-19 vaccine, which has been developed jointly by Canada and China.
However, according to Reuters, scientists outside the company have expressed concern that the effectiveness of CanSino’s Ad5-nCoV vaccine, which is based on a common cold virus to which many people have been exposed, could be limited. The news agency reported that scientists said existing antibodies against the common cold virus might undermine the vaccine.