Q; 53 years old male is recovering in ICU from severe dengue virus infection after his trip to Columbia. He asked for possible vaccination against Dengue virus (DENV). Infection from Dengue virus automatically provide lifelong immunity against it and doesn't require protection, and should only be administrated to people with no history or laboratory evidence of the previous infection.
Contrary to expectations, administration of Dengue vaccine to people without any previous exposure can do more harm than benefit. But it should be administrated to people with previous experience of DENV, as the chances of severity go up in the second infection.
Treatment is mostly preventive, and if acquired, supportive with fluid resuscitation.
http://www.who.int/immunization/diseases/dengue/q_and_a_dengue_vaccine_dengvaxia/en/ (World Health Organization)