Vestibular Neuritis (Labyrinthitis): This condition is characterized by sudden onset vertigo, often following a viral respiratory infection, and can include hearing loss. The absence of evidence for right middle ear infection supports this diagnosis, as it typically involves the inner ear.

Meniere's Disease: Although it typically presents with episodic vertigo, hearing loss, and tinnitus, the recent onset and combination of symptoms could initially suggest Meniere's, especially if the vertigo is constant and there's a history of similar episodes.
Acute Otosclerosis: This condition can cause vertigo and hearing loss, but it's less likely given the sudden onset and recent respiratory infection.

Stroke (Lateral Medullary Syndrome or Cerebellar Infarct): Although less likely, a stroke can present with sudden vertigo and must be ruled out due to its severe consequences. The presence of other neurological deficits would increase suspicion.
Multiple Sclerosis: This condition can cause vertigo among other neurological symptoms, and while less common, its diagnosis is critical due to its long-term implications.

Autoimmune Inner Ear Disease: A rare condition that can cause sudden hearing loss and vertigo, often bilateral, and may be associated with systemic autoimmune disorders.
Syphilis (Otosyphilis): A rare cause of hearing loss and vertigo, especially in the context of congenital syphilis or late-stage acquired syphilis.
Cogan Syndrome: A rare disorder characterized by recurrent corneal inflammation and vestibular-auditory symptoms, which could present with vertigo and hearing loss.