Sinovac Biotech’s experimental COVID19 vaccine has shown promising results in the early trial. The vaccine has been able to activate a quick immune response. However, the level of antibodies triggered by the vaccine has been less than in people who have recovered from the disease. Experts have said that the early mid-stage trial has not been conducted to test the efficacy of the vaccine called CoronaVac. They have said that as compared to other vaccines and data from preclinical studies with macaques, this vaccine might offer enough protection. The findings of this study have been released after drug companies from the US Pfizer and Moderna have declared that their vaccines have been proved to be 90 percent effective in the large and late-stage trials. Four other vaccines along with CoronaVac, which are being developed by China, are in the late-stage trials, which will test their safety and efficiency.
The early mid-stage findings have been derived from phase 1 and phase two clinical trials, which have been conducted in China. These trials have enrolled around 700 participants. The lead author of the study, Dr. Zhu Fengcai has claimed that the findings of the trials show that two doses of the vaccine at a 14 days gap will trigger a quick immune response within four weeks of vaccination. Dr. Zhu has said that this vaccine might be appropriate for emergency use amidst the pandemic. However, there have been certain limitations in the phase two trial. Experts have noted that the phase two trial has included only healthy individuals. It has not enrolled people from a group, which is more susceptible to COVID19. Phase two trial has not involved people above 60 years and those who have been dealing with underlying health issues.
The phase two trial of the CoronaVac vaccine has not been able to test the T-cells response, which will be included in certain parts of the phase three trial, which is being conducted in Brazil. Phase three trial of this vaccine is under process in Indonesia and Brazil. These countries as well have reported most COVID19 cases after the US and India. Several experts from around the world have said that the findings of this early mid-stage trial must be treated with caution until the results of the phase three trial are out. The other two vaccines developed by China as well have shown positive responses in the early mid-stage trials. The finding of the early mid-stage trial of CoronaVac has been released in the medical journal The Lancet Infectious Disease.