Coronavirus: China’s CanSino says vaccine booster shot can reverse drop in antibodies
- A second dose six months after the single-shot vaccine can make antibody levels spike about eight-fold in two weeks, CanSino’s chief scientific officer said
The decline in antibodies does not necessarily mean the shots will lose their protection, though how fast they wane could still serve as an important indicator of the immune response, Zhu Tao, chief scientific officer at CanSino, said in an online presentation.
Apart from durable antibodies, researchers have said that other components in a person’s immune system elicited by Covid vaccines, such as T cell and B cell memory, may also contribute to protection.
Six months after being inoculated with a CanSino vaccine, neutralising antibodies were at roughly 70 per cent of the level seen 28 days after the shot, Zhu said, citing data from 35 vaccinated people.
When a second dose was given after six months, antibody levels shot up about eight-fold two weeks after the shot, Zhu said, citing data from 28 people.
What next for Chinese vaccines after first WHO approvals?
A third booster shot of CanSino’s vaccine three to six months after the second shot of an inactivated vaccine generated significantly higher antibody levels, versus using an inactivated vaccine as a third-dose booster, Zhu said, citing data from about 200 participants in a clinical trial.
