Dr. Manish Sadarangani, the Sauder Chair in Pediatric Infectious Diseases at the University of British Columbia: "at least 90-95% of the population need to be vaccinated" (https://www.ovg.ox.ac.uk/news/herd-immunity-how-does-it-work)

Sebastian Funk, Associate Professor at the Centre for the Mathematical Modelling of Infectious Diseases at the London School of Hygiene & Tropical Medicine: "to achieve [termination of measles transmission,] the population immune needs to be 93-95%, the herd immunity threshold." (https://www.who.int/immunization/sage/meetings/2017/october/...)