Results of the initial phase clinical trials of a Chinese Covid-19 vaccine appears to be safe. It is also generating a good antibody response.
CoronaVac which Sinovac Life Sciences in Beijing manufactures contains an inactivated SARS-CoV2 virus. “The Lancet Infectious Diseases” journal published the results of the initial trial.
The researchers said that two doses of CoronaVac at different concentrations and using different dosing schedules had goof tolerance and moderately immunogenic in healthy adults aged between 18–59 years. The incidence of adverse reactions in the 3 micrograms and 6 microgram groups were similar. This indicates that no dose-related safety concerns are present but there will be a need for a more long-term follow-up.
According to the research, the adverse reactions were mild. The most common symptom was injection-site pain, which is in accordance with previous findings for another Covid-19 vaccine from Sinopharm, Beijing.
The Occurrence Of Fever After Covid-19 Vaccination With CoronaVac Is Relatively Low
Compared with other Covid-19 vaccine candidates such as viral-vectored vaccines or DNA or RNA vaccines, according to the researchers, the occurrence of fever after vaccination with CoronaVac was relatively low. There were reports of only one case of acute hypersensitivity, with the manifestation of urticaria 48 hours after the first dose of the study drug.
There was an enrollment of around 144 participants in the phase 1 trial of the vaccine candidate. This was between the 16th and 25th of April. And the enrollment in its phase 2 trial between 3rd and 5th May were of 600 participants. A total number of 743 participants had received at least one dose of the vaccine.
The mean neutralizing antibody titers induced by CoronaVac ranged from 23.8 to 65.4. This range is lower than levels observed in people who have previously had Covid-19. The average level is 163.7.
Dr. Gang Zeng who is one of the authors of the study, from Sinovac Biotech said that the CoronaVac is one of many Covid-19 vaccine candidates that is explored in parallel. There are a multitude of different vaccine technologies under investigation, each with its own advantages and disadvantages. CoronaVac could be an attractive option among the many vaccines. This is because of its storage ability in a standard refrigerator between 2 and 8 degrees centigrade. This is typical for many existing vaccines, including flu. The vaccine may also remain stable for up to three years in storage. This will offer some advantages for distribution to regions where access to refrigeration is challenging. But data from phase 3 studies will be crucial before any recommendations about the potential uses of CoronaVac can be made.