Antibodies from Sinovac's Covid-19 shot fade after about 6 months, booster helps: study

BEIJING (Reuters): Antibodies triggered by Sinovac Biotech's Covid-19 vaccine declined below a key threshold from around six months after a second dose for most recipients, but a third shot had a strong booster effect, a lab study showed.

Chinese researchers reported the findings from a study of blood samples from healthy adults aged between 18-59 in a paper published on Sunday (Aug 8), which has not been peer reviewed.