Chinese Covid-19 vaccines "don't have very high protection rates", China's top disease control official said on Saturday, Apr. 10.

Gao Fu, the director of the China Centers for Disease Control, added that China is thinking of mixing different vaccines to boost the effectiveness of vaccines.

He said the government is now formally considering if they should use "different vaccines from different technical lines for the immunisation process", The Washington Post reported.

Another CDC official, immunisation expert Wang Huaqing, also said that Chinese developers are now working on mRNA-based vaccines, which have entered the clinical trial stage.

No foreign vaccine has been approved in China at the moment.

Clarified his claims later on

Gao later claimed that his comments had been misinterpreted.

Telling Global Times it was a "complete misunderstanding", he refuted making the claim that Chinese vaccines have a low protection rate.

He said the protection rates of all vaccines in the world are "sometimes high, and sometimes low", and improving their efficacy is a question that scientists need to consider.

He further stressed that as this is the "first time" that humans have encountered Covid-19, and so there are "many scientific questions that need to be addressed".

Gao added that "everyone should consider the benefits mRNA vaccines can bring for humanity".

He had previously raised doubts about the safety of mRNA vaccines, telling Xinhua that negative side effects might occur as they were used for the first time on people with no health problems.

While Chinese firms uses traditional vaccine technology that uses inactivated Covid-19 to trigger an immune response, Pfizer-BioNTech and Moderna make use of the newer mRNA technology to activate the immune system against the virus.

China's vaccine diplomacy

China has promoted its own vaccines while raising doubts about the efficacy of Western vaccines.

Following criticisms from the West for not disclosing sufficient data on its vaccines, the Global Times criticised media outlets in the U.S. and Europe for "deliberately downplaying the deaths" of some frail patients after getting their Pfizer-BioNTech shots.

They also accused Western media of deliberately reporting about Chinese vaccines in a bad light.

The World Health Organisation (WHO) said lately that both Chinese vaccine makers, Sinovac (a private company) and Sinopharm (a state-owned company) have submitted data on their vaccines that show efficacy levels that fit WHO requirements, Reuters reported.

The global health body said Chinese vaccines have an efficacy of at least 50 per cent, adding that safety data presented indicates that the vaccines would not harm humans when used.

Previously, WHO said Sinovac and Sinopharm vaccines could receive WHO emergency listing "quite soon".

Efficacy readings of Sinovac's vaccine have varied. A recent Brazil phase 3 trial revealed that it has an efficacy rate of 50 per cent, while results from a phase 3 trial in Turkey show that they are 91.25 per cent effective.

Sinovac has acknowledged varying levels of efficacy, but said they can be attributed to the different ages of people in the studies, the strain of virus, as well as other factors.

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