A staff member checks the packaging of the Sinopharm vaccines in Beijing, capital of China, May 31, 2021. Photo: Xinhua

Chinese vaccine producers are conducting tests against Delta variant on their products, companies officials told the Global Times on Thursday during the Business Dialogue on Vaccine Cooperation, hosted by the Chinese Foreign Ministry. 

Yang Xiaoming, Chairman of Sinopharm China National Biotec Group, a Sinopharm subsidiary, told the Global Times on Thursday that the company is conducting neutralization tests on the Delta variant with serum of vaccine recipients and is ramping up the development of vaccines targeting the four dominating variants: Alpha, Beta, Gamma and Delta. 

According to Yang, Sinopharm's vaccine for the Beta variant, first discovered in South Africa, is undergoing animal tests. The vaccine test for the Delta variant is currently under development.  

Currently, Sinopharm's inactivated vaccines are still effective in protecting recipients from dominating variants, Yang said. 

China has administered more than 1.6 billion doses of COVID-19 vaccines as of Wednesday. However, some cases of people infected after being inoculated have been reported during the recent Nanjing outbreak.

Yang explained that there is no COVID-19 vaccine in the world that can ensure 100 percent protection against infection. The efficacy of vaccines consists of various criteria, including the efficacy to prevent death and critical disease. 

Regarding Sinopharm's inactivated vaccine, Yang noted that the results of the three phases of the clinical trials and its use on a large populations have demonstrated it is very effective and safe.     

The Global Times learned from Sinovac and Zhifei Longcom, a unit of Chongqing Zhifei Biological Products ,that they are also developing vaccines against the Delta variant, adding that their current vaccines are still effective against variants.

Yang Guang, Chief Business Officer for Sinovac Biotech Ltd and General Manager of Sinovac Biotech (Hong Kong) Ltd, also said that they are conducting tests on the Delta variant to develop special vaccines for this variant. 

Real-world data from a study by Sinovac in Chile has shown that Sinovac's vaccine provides effective protection against the Gamma variant. Our study on the vaccine's efficacy on the Delta variant has also reached similar results, Yang Guang noted.