Narrow-band far-ultraviolet C (λ = 200-230 nm) light-emitting diodes (far-UVC LEDs) are strongly detrimental to airborne pathogen like bacteria and viruses while minimally invasive to human health so they can be used as a disinfectant to suppress the outbreak of infectious diseases with minimum safety concerns. Herein, we investigate a design of AlGaN/AlN nanowire structure in combination with a bandpass filter for a narrow band far-UVC LED at 222 nm center wavelength. The LED achieves an ultra-narrow full width at half maximum (FWHM) of ~12 nm after introducing a metal-dielectric Fabry-Perot optical bandpass interference filter with three periods of Al/MgF2/Al layers. The electrical and optical properties of the nanowire LEDs show the high performances with an internal quantum efficiency (IQE) up to 80% and the maximum power exceeding 10 mW at a current injection of 60 mA. This narrow-band far-UVC LED is a promising candidate for airborne and surface disinfection in occupied spaces to prevent the spread of contagious diseases.