China-based Sinovac Biotech has reported positive preliminary data from the Phase I/II clinical trials of its Covid-19 vaccine candidate, CoronaVac.

Results from the randomised, double-blind and placebo-controlled trials showed favourable immunogenicity and safety profiles. Of the total 743 healthy participants aged 18 to 59 years, 143 are in Phase I and the remaining 600 in Phase II.

Investigators did not report any severe adverse event in Phase I or Phase II trials. In the Phase II trial, the vaccine triggered neutralising antibodies 14 days following the vaccination with a 0,14 day schedule.

The neutralising antibody seroconversion rate was observed to be more than 90%, which is said to indicate that the vaccine can stimulate positive immune response.

Sinovac Biotech chairman, president and CEO Weidong Yin said: “Our Phase I/II study shows CoronaVac is safe and can induce immune response. Concluding our Phase I/II clinical studies with these encouraging results is another significant milestone we have achieved in the fight against Covid-19.

“We have started to invest in building a manufacturing facility so that we can maximise the number of doses available to protect people from Covid-19. Like with our other vaccines, we are committed to developing CoronaVac for global use as part of our mission of supplying vaccines to eliminate human diseases.”

The company intends to submit a Phase II study report and a Phase III study protocol to China’s National Medical Products Administration soon. Sinovac is also planning to commence application for Phase III trials outside of China.

Last week, the company partnered with Brazil-based Instituto Butantan to advance  CoronaVac into Phase III studies. Instituto Butantan agreed to sponsor Phase III trials of the Covid-19 vaccine candidate in Brazil.

The partners may enter additional agreements in the future for technology licensing, market authorisation, and commercialisation of CoronaVac.