Which organism is prevented by the Hib vaccine and commonly causes meningitis in young children?

• A. Haemophilus influenzae
• B. Neisseria meningitidis
• C. Streptococcus pneumoniae
• D. Streptococcus pyogenes

Answer: (A)

Preventing meningitis in young children is a major goal of vaccination. The Hib vaccine targets Haemophilus influenzae type b, a bacterium that used to be a leading cause of bacterial meningitis in kids under five. By provoking antibodies against the type b capsule, the vaccine blocks Hib infections, including meningitis, making Haemophilus influenzae the organism the Hib vaccine is designed to prevent. Other pathogens listed can cause meningitis but are addressed by different vaccines or are less commonly associated with Hib vaccination, such as Neisseria meningitidis (meningococcal vaccines) and Streptococcus pneumoniae (pneumococcal vaccines). Therefore, the organism prevented by the Hib vaccine and commonly causing meningitis in young children is Haemophilus influenzae.