Denis Kainov received his PhD in Genetics from the University of Helsinki (UH), Finland for his work in assembling cystoviruses from purified RNA and proteins. He completed first postdoctoral training at IGBMC, France where he deciphered molecular mechanism of rare neurodevelopmental repair syndrome known as group A trichothiodystrophy. He completed his second postdoctoral training at CRP-Sante, Luxembourg, where he discovered that the anticancer agent saliphenylhalamide suppressed the replication of the influenza virus in vitro and in vivo. This led to his first independent position at the UH, where he continued to repurpose drugs for viral diseases. His lab has shown that many repurposed agents have broad-spectrum antiviral activities. Furthermore, he has shown that some combinations of antiviral agents suppressed viral replication at lower concentrations than monotherapies, reducing side effects. The results of his research allowed him to take a professor position at NTNU, Norway, and visiting research positions at UH, Finland and TUIT, Estonia, and prepare well for the SARS-CoV-2 pandemic. During the pandemic, he showed that broad-spectrum antivirals and their combinations can be used for the treatment of SARS-CoV-2, its immune-evading and drug-resistant variants, and viral co-infections. He published and patented his results (78 papers and 2 patent applications).