China-based CanSino Biologics is set to launch a Phase III clinical trial of its Covid-19 vaccine candidate, Ad5-nCOV, in Saudi Arabia soon.

Last month, the company was in discussions with Russia, Brazil, Chile and Saudi to conduct a Phase III trial of the potential vaccine.

The vaccine is made up of a harmless cold virus known as adenovirus type-5 (Ad5) to deliver genetic material from the coronavirus into the body. It was developed in collaboration with China’s military research unit.

According to Saudi Ministry of Health, the Phase III trial will enrol approximately 5,000 subjects. The study will compare Ad5-nCOV to placebo.

Saudi is said to be preparing to perform the study across multiple cities, including Riyadh, Dammam and Mecca.

In a statement, Saudi Ministry of Health said: “Research teams will follow up on participants after they take a dose to ensure that no side effects appear.

“The follow-up will be through direct visits by the patients to the doctors participating in the study. Patients will also undergo all necessary immunological tests. Furthermore, electronic follow-up methods will be used.”

Previous trial data showed that the vaccine candidate was safe and induced immune responses in most participants. CanSino conducted the first and second phase studies of the vaccine in China.

The first phase evaluated three different doses of the vaccine in 108 volunteers in China from 16 to 27 March while the second phase tested two doses in 603 subjects from 11 to 16 April.

Results demonstrated favourable efficiency profile, with Covid-19 antibodies observed in the plasma of the participants. Few side effects were reported, primarily with low vaccine doses.

Another Chinese company, Sinopharm, initiated a Phase III trial last month to assess its Covid-19 vaccine candidate in Abu Dhabi, UAE.