title: Reply to Kerkhove et al and Oh.
authors.affiliation: Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine.
authors.forename: Sung-Han
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Architectural Engineering, Sejong University, Seoul.
authors.forename: Minki
authors.initials: M
authors.lastname: Sung
authors.affiliation: Respiratory Viruses Research Laboratory, Institut Pasteur Korea, Seongnam-si, Gyeonggi, Republic of Korea.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Min