Early in his youth, he succeeded in developing an anti-polio medicine with locally available raw materials, which was introduced throughout the country to root out the cause of poliovirus disease.

Over the past 50 years, he has developed many kinds of vaccines, including bird flu vaccine and influenza incrassation vaccine.

In recent years, he invented a new method of tissue culture based on domestic materials and settled technical problems in establishing a new vaccine production process. The vaccines, mass-produced by this method, are well received by users as they are of high economic value and efficacious in treatment without giving adverse effect on human body.

Prof. and Dr. Ri is a winner of the title of DPRK Labor Hero and a candidate academician.