BEIJING: Vaccine developer BioNTech has extended by six months to October a Phase II clinical trial of its COVID-19 vaccine in China, a registry of such trials showed.

The vaccine, based on messenger RNA (mRNA) technology, is one of the most widely used worldwide against COVID, but has yet to receive an approval in China, which has relied only on domestically developed vaccine.

China’s leading medical experts have urged authorities to retain tough zero-COVID measures so as to buy time and step up vaccination rates and develop new treatments, in the battle on the country’ biggest outbreak.

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The Phase II trial on the vaccine’s safety and immunogenicity began in late 2020, targeting completion by the end of April, but this was extended to the end of October, according to a database managed by an agency under the US National Institutes of Health.

BioNTech and its Chinese partner, Shanghai Fosun Pharmaceutical Group, were not immediately available to comment.