Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
immunogenic is an adjective meaning "possessing the ability to elicit an immune response". It carries one recorded sense.
possessing the ability to elicit an immune response
Definitions, synonyms and semantic relations for immunogenic come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.