An absorbent article such as a sanitary napkin, panty liner, incontinence protector, diaper, includes an absorbent structure (4) with a first and a second side, a moisture sensitive additive (8), such as a bacterial composition, and a carrier member (10). The carrier member (10) includes a first and a second water-vapour impermeable material layer (12, 13), the material layers are sealed together by a sealing (11) to form a water-vapour impermeable volume (9) there between holding the moisture sensitive additive (8). The carrier member (10) is located on the first or the second side of the absorbent structure (4).