Results from a phase 1/2 randomised clinical trial of a Chinese vaccine candidate based on the inactivated whole SARS-CoV-2 virus (CoronaVac) suggest the vaccine is safe and induces an antibody response in healthy volunteers aged 18 to 59 years.
The findings, published in Lancet Infectious Diseases show that antibody responses could be induced within 28 days of the first immunisation, by giving two doses of the vaccine candidate 14 days apart.
The mean neutralising antibody titres induced by CoronaVac ranged from 23.8 to 65.4, which are lower than levels seen in people who have previously had COVID-19 (average level of 163.7). However, the researchers still believe CoronaVac could provide sufficient protection against COVID-19 based on their experience with other vaccines and data from their preclinical studies.
The study only included healthy adults aged 18-59 years. Further studies will need to test the vaccine in other age groups and in people with pre-existing conditions.
Phase 3 trials of CoronaVac are underway in Brazil, Indonesia and Turkey. Studies in Brazil were recently paused for investigation of an adverse event but have now resumed.
CoronaVac is one of 48 COVID-19 vaccine candidates for COVID-19 that are currently in clinical trials.