 In 1997 Fiers retired and became Professor Emeritus, the following year he retired from his position as director of the Laboratory of Molecular Biology.Together with Xavier Saelens and their team, he continued his research, to find a universal influenza vaccine, based on the M2 protein on the surface of the influenza A virus.The ectodomain of the M2 protein remains unchanged in all human influenza viruses known, including the strains that caused the pandemics in the last century, which makes it eligible for a universal influenza A vaccine.