Three doses of Chinese vaccine fail to protect against Omicron in study

The research suggests that people who’ve received Sinovac’s shot, known as CoronaVac, should seek out a different vaccine for their booster: Getting Germany’s BioNTech SE’s messenger RNA as a third dose saw those previously fully vaccinated with CoronaVac significantly improve in protective levels of antibodies against omicron, according to the study from the University of Hong Kong and The Chinese University of Hong Kong.

Two doses of the BioNTech shot, known as Comirnaty, was also insufficient, though adding a booster of the same type raised protection to adequate levels, the researchers said in a statement.

While much is still unknown about how Sinovac’s shot holds up to omicron — including how T cells, the immune system’s weapon against virus-infected cells, will respond — the initial results are a blow to those who have received CoronaVac. There have been more than 2.3 billion doses of the shot produced and shipped out, mostly in China and the developing world.