Chinese vaccine triggers quick immune response

Sinovac Biotech, one of China’s most promising Covid-19 candidates, has announced its vaccine has triggered a quick immune response. The news comes hot off the heels of breakthroughs by Pfizer and Moderna.

Sao Paolo, the Brazilian state ravaged by the Covid pandemic, has ordered 46 million doses. President Jair Bolsonaro, who himself has recovered from Covid-19, and the federal government say they remain open to multiple vaccine candidates.

Preliminary trial results show that, while the immune response was fast, the level of antibodies observed was lower than in those who have recovered from the virus. However, researchers are satisfied with the level of response – citing preclinical trial evidence and an understanding of how vaccines behave.

Published in blue ribbon medical journal Lancet Infectious Diseases, Sinovac’s late-stage clinical trial consisted of more than 700 participants. According to study author, Zhu Fengcai, the vaccine triggered a positive immune response after participants were administered two doses over a month. The Sinovac vaccine is suitable for emergency use during the pandemic, Zhu said.

Sinovac is currently conducting late-stage trials in Brazil and Indonesia – both of which have sought early access to the vaccine. Sao Paulo, home to more than 40 million people, has a supply deal with the vaccine producer and is importing 46 million doses of the life-saving drug, according to Reuters.

Indonesia has sought emergency use of the Sinovac and Sinopharm vaccines, both of which are in stage three trials.

In the second week of November, Sao Paulo had 1.12 million active cases and more than 39 000 deaths.

Sao Paulo-based medical firm, Instituto Butantan, which placed the order, is expected to be ready to roll out the vaccine in January if Brazil’s health regulator, Anvisa, clears usage. Ricardo Palacios, the trial manager at Instituto Butantan, said the Sinovac vaccine has an excellent safety profile, making it an ideal candidate.

Sinovac’s vaccine candidate does not face some of the logistical challenges posed by the likes of Pfizer and Moderna – both of which need to be refrigerated at -70 degrees Celsius. Created using existing vaccine technology, Sinovac’s Covid-19 drug can be stored at standard refrigeration temperatures of near freezing and remain potent for three years.

China has multiple candidates in early and mid-stage testing, including CanSino and Sinopharm candidates, both of which have induced a positive immune response, according to peer reviewed studies.