It was clear that virology research was becoming increasingly important within IPO, among other things due to the growing understanding in international science of how viruses worked and their impact on plant, animal, and human health. In 1956, it was therefore decided to establish a separate virology laboratory and convert Thung’s chair by special appointment into a ‘regular’ chair.

Thung was officially appointed Professor of Virology at the Agricultural College and had to leave IPO. His IPO-colleagues did not let this farewell go by unnoticed; they presented him a beautiful illustrated album amicorum.