This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
All the following are conjugate vaccines Except 
Select and explain. 
A. Haemophilus influenzae type b, B. Pneumococcal, C. Neisseria meningitidis, D. Hepatitis A
D: Hepatitis A
Answer: D: Hepatitis A 
Explanation: Subunit Vaccines* Haemophilus--purified capsular polysaccharide conjugated to protein* Neisseria meningitidis--capsular polysaccharides, pediatric version is conjugated to protein* Pneumococcal--capsular polysaccharide (7 and 23 serotypes) (pediatric version is conjugated to protein) Ref : Ananthanarayana textbook of Microbiology 9th edition Pgno : 83