China's Sinopharm is developing updated versions of its Covid-19 vaccines based on the Beta and Delta variants, according to an article published Monday by the company.

The Chinese state-owned vaccine maker is conducting animal tests for an inactivated vaccine based on the variant discovered in South Africa, according to the article on the company's official account on WeChat. The company didn't specify at which stage the study on the Delta variant, first identified in India, was progressing.

In a meeting organized by China's Foreign Ministry on Thursday, Sinopharm's senior official Yang Xiaoming briefed state officials and vaccine makers that lab studies based on blood samples from people who have taken the company's shots have found the vaccines were able to neutralize four coronavirus variants including the Delta strain, the article said.

The Delta variant was found in the center of several outbreaks in China over the past months. The most recent infections, first starting in the eastern city of Nanjing late last month, have quickly spread to a dozen of provinces and major cities. That has triggered doubts over the protection of Chinese vaccines against the Delta variant and accelerated calls for booster shots.

China is administering two inactivated Covid-19 vaccines developed by Sinopharm, one of which was approved by the World Health Organization for emergency use.

Researchers in Sri Lanka have found that the antibody levels to the Delta variant triggered by the WHO-approved Sinopharm vaccine dropped 32% compared with the Wuhan strain, according to a study published last month that hadn't been peer reviewed.

Chinese officials said Saturday that they haven't seen the need to give a booster shot to ordinary people who have completed the vaccination regimen in the past year, based on preliminary studies, while further research is under way to determine whether and when it is necessary to give a third shot to those with higher risks of being infected, including the elderly and medical workers.

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(END) Dow Jones Newswires

08-02-21 0731ET