A week after one of its tests in Brazil was stopped amid a safety scare, Chinese biotech Sinovac has published data showing its experimental COVID-19 vaccine can quickly boost an immune response.
Published in the journal Lancet Infectious Diseases, the phase 1/2 trial for Sinovac’s CoronaVac inoculation across more than 700 patients was not set up to assess efficacy, but it did show it could provide sufficient protection against SARS-CoV-02.
This, the biotech said, is based on its experience with other vaccines and data from preclinical studies with macaques. “Our findings show that CoronaVac is capable of inducing a quick antibody response within four weeks of immunization by giving two doses of the vaccine at a 14-day interval,” the researchers said in the journal.
This will not create the same excitement as Moderna and Pfizer/BioNTech’s phase 3 top-line peek this month, which showed their vaccines could offer 90%-plus efficacy, though these data still need to be published in full and peer reviewed and were later-stage efforts with different endpoints than the early tests from Sinovac published today.
The Sinovac tests were done in the early days of the pandemic, in April and May, with later-stage efforts now ongoing; the trial was also assessing what dose to use in these tests, with the biotech finding the 3-μg dose of CoronaVac would be used for phase 3 studies.
Sinovac is already pushing ahead with late-stage trials, although one phase 3 trial of its vaccine was stopped in Brazil this month after reports of a serious safety concern, with one report stating a death is involved but that it was not in the vaccine arm.
Sinovac is also undertaking phase 3 trials in Turkey and Indonesia as well as Brazil; data from these are assessing efficacy and will be the real litmus test for this vaccine.