Conjugate vaccines are available for the prevention of invasive disease caused by all of the following except

Conjugate vaccine is now available where polysaccharide antigen is conjugated to diphtheria toxoid which makes the vaccine immunogenic to children below 2 years. Monovalent and polyvalent vaccines containing capsular polysaccharide of Meningococci group A, C, W-135 and Y are available. Induces good immunity after a single dose in older children and adults Little value in children below the age of two years as polysaccharide antigen is T cell independent. Immunity is group specific. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 233