WordNet records no synonym and no antonym for airborne transmission. It is the only member of its synset, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a transmission mechanism in the which the infectious agent is spread as an aerosol and usually enters a person through the respiratory tract
Synonyms, antonyms and the broader and narrower relations for airborne transmission come from Princeton University’s WordNet. Full sources and licences.