China approves mixed-vaccine trial as Delta variant spreads

Inactivated virus and DNA-based jabs to be combined in bid to achieve higher efficacy

BEIJING: China’s drug regulator has approved the country’s first mixed-vaccine trial, a company involved in the study said, as the rapid spread of the Delta variant raises concern about the efficacy of domestically produced jabs.

The trial will test the efficacy of combining an “inactivated” vaccine made by China’s Sinovac with a DNA-based one developed by US pharmaceutical company Inovio, a statement issued on Tuesday said.

The statement was issued by Advaccine Biopharmaceuticals Suzhou, Inovio’s trial partner in China.

Preclinical work has found that “two different vaccine applications produce an even stronger and more balanced immune response”, said Advaccine chairman Wang Bin.

There are several types of Covid vaccines, including those using an inactivated or weakened virus to generate an immune response, and more cutting-edge RNA or DNA-based jabs that use engineered versions of the coronavirus genetic code to create a protein that safely prompts an immune response.

Five out of the seven vaccines approved in China are two-shot inactivated vaccines.

Their published efficacy lags RNA jabs by Pfizer-BioNTech and Moderna, which have pre-Delta success rates above 90%.

The World Health Organisation has said there is still not enough data to say whether using two different vaccines together is safe or can boost immunity.

Inovio has not published any efficacy data from its global clinical trials. It is the first DNA-based vaccine to be tested in China.

China is battling its worst Covid outbreak in months, with officials saying many of those infected had already been vaccinated.

This has added to calls for China’s two biggest vaccine producers – state-run Sinopharm and privately owned Sinovac – to provide data proving their jabs work against the Delta variant.

Beijing has yet to approve any foreign vaccines for domestic use.

On Tuesday, Chinese health authorities reported 143 new coronavirus infections.

Dozens of cases in recent days have been linked to a Covid-19 testing site in eastern Yangzhou city.

In a sign of the anxiety over even relatively minor outbreaks, several officials have been issued warnings for mishandling mass testing, which city authorities said allowed the virus to spread.

Yangzhou city authorities said “a small number of party members and cadres have yet to perform their duties properly”.

The city of 4.6 million people has so far conducted five rounds of widespread testing, collecting 1.6 million samples in an attempt to stamp out the spread. – AFP