CanSinoBIO with Sinovac yields strong response

A Chinese study looking at mixing COVID-19 vaccines showed that receiving a booster shot of CanSino Biologics' vaccine after one or two doses of Sinovac Biotech's vaccine yielded a much stronger antibody response than using the Sinovac shot as a booster.

The study, among the first analyses in China combing different COVID-19 vaccines, comes as the country said it would use booster shots in specific groups amid concerns over vaccines' waning protection over time.

Participants who received a CanSinoBIO booster dose three to six months after a second Sinovac shot showed a 78-fold jump on average in neutralizing antibody levels two weeks later, according to a paper published on Monday before a peer review.

By contrast, those who received a Sinovac booster shot showed a 15.2-fold increase in neutralizing antibody levels, researchers from local disease control authorities, CanSinoBIO and other Chinese institutions said in the paper.

One dose of Sinovac followed by a CanSinoBIO booster at intervals of one or two months led to a 25.7-fold increase in neutralizing antibody levels, while two doses of Sinovac induced a 6.2-fold increase.

The study analyzed data from about 300 healthy adults aged 18-59. It did not assess the boosters' protection against COVID-19 and did not test the neutralizing antibody against the more transmissible Delta variant.