Guillen is currently Biomedical Research Director at the Center for Genetic Engineering and Biotechnology (CIGB) in Havana. He received his Bachelor in Science degree in Chemistry and his Master in Chemistry in 1986 in Odessa I.I. Mechnikov National University, and his PhD degree in Biological Sciences in 1995 from Havana University. He joined the CIGB in 1986. For more than 25 years, he was supervisor of several projects related to prophylactic and therapeutic vaccine developments on hepatitis, dengue, meningitis, pertussis, cancer and COVID as well as drug development against infectious diseases, cancer, cardio protection, neuro-protection and wound healing. Guillen is a Senior Researcher at CIGB, Full Professor at the Havana University and Latino American School of Medicine, Distinguished Professor-at-Large at the University of Science and Technology of China and has been a Member of the Cuban Academy of Science since 2012. He is also member of several scientific societies, editorial boards and advisory committees. He has published 226 scientific papers and holds 56 patents. He has been honored with 52 National Awards for Scientific Results from the Cuban Academy of Sciences.