MERV-14 filters are rated for 75% efficacy in that range: https://www.nafahq.org/understanding-merv-nafa-users-guide-to-ansi-ashrae-52-2/ https://www.nafahq.org

MERV-14 filters are rated for 75% efficacy in that range: https://www.nafahq.org/understanding-merv-nafa-users-guide-to-ansi-ashrae-52-2/ https://www.nafahq.org/understanding-merv-nafa-users-guide-t... The respiratory particles that transmit covid are a range of sizes, but likely mostly a bit larger than that: https://www.jefftk.com/p/how-big-are-covid-particles https://www.jefftk.com/p/how-big-are-covid-particles