This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
Vaccine for post splenectomy infection is given against all except : 
Select and explain. 
A. Streptococcus pneumonia, B. Haemophilia influenza, C. Neisseria meningitides, D. E.coli
D: E.coli
Answer: D: E.coli 
Explanation: Splenectomy : Most serious sequela is overwhelming postsplenectomy infection (OPSI), with meningitis, pneumonia, or bacteraemia OPSI is typically caused by polysaccharide-encapsulated organisms, such as Streptococcus pneumoniae, Neisseria meningitidis & Hemophilus influenzae When elective splenectomy us planned, vaccination against encapsulated bacteria should be given atleast 2 weeks before surgery If spleen is removed in emergency, vaccination should be given as soon as possible Vaccines should be given for Streptococcus pneumoniae, Hemophilus influenza type B & Meningococcus In addition to above given 3 vaccines, annual influenza immunization is also advised as influenza has been implicated as a risk factor for secondary bacterial infections Booster injections of pneumococcal vaccine should be given every 5-6 years Harrison says "Routine Chemoprophylaxis with oral penicillin can result in the emergence of drug-resistant strains and is not recommended" Ref: Sabiston 20th edition Pgno : 1564