"Treatment for influenza and its complications was mostly supportive care. Palliatives from pharmacies and vendors were encouraged, if not presented as cures. No antivirals or antibiotics were available; penicillin was not discovered until 1928. One potentially effective therapy for reducing the risk of death was use of convalescent sera collected from patients after their infection and administered to patients with current infection. Many more physicians, however, attempted to treat patients with “vaccines”. At the time, Haemophilus influenzae was the presumed etiologic agent for influenza, referred to as Pfeiffer’s bacillus. Vaccines were made from culture of the bacillus and may have been effective at reducing some secondary bacterial coinfections."