The South Korean government has prepared standards in putting together a plan to clinically compare the efficacy and safety of locally developed and previously approved COVID-19 vaccines.

The Ministry of Food and Drug Safety on Monday put forth three types of standards, one for first- and second-phase clinical studies, another for third-phase clinical studies and the last for comparative third-phase clinical studies.

This is a part of efforts to support local pharmaceutical companies in vaccine development, as it would be difficult to find a placebo control group for clinical studies while nationwide vaccinations are under way.

Instead, approved vaccines and those in development would be compared in accordance with standards for immunogenicity with the same types of neutralizing antibodies.

National Institute of Food and Drug Safety Evaluation Director General Seo Kyung-won said a minimum of three-thousand subjects would be required for the comparative study.

Seo added that the government plans to persuade the World Health Organization to exercise flexibility in recognizing the scientific feasibility of such clinical studies.