Which vaccine is not recommended for children over age 5 years?

The Haemophilus influenzae type b (Hib) vaccine is typically not recommended for children over the age of 5 years because the risk of Hib disease after this age is significantly lower. The Hib vaccine is primarily designed to prevent infections caused by the Hib bacteria in young children, particularly those under the age of 5, who are at a greater risk of serious illnesses, such as meningitis and pneumonia, caused by this organism.

As children grow older, their immune systems develop and the likelihood of contracting serious Hib infections decreases. Current vaccination guidelines recommend administering the Hib vaccine in early childhood, typically in a series of doses starting at 2 months of age and completing the series by the time the child is 15 months old. After 5 years of age, children usually have developed sufficient immunity, making further vaccinations unnecessary.

In contrast, the vaccines for diphtheria, pertussis, tetanus (DTaP), inactivated poliovirus (IPV), and hepatitis B continue to be important for children beyond the age of 5, as they protect against diseases that can still be contracted during older childhood and adolescence. Thus, focusing on Hib as the vaccine not recommended for children over age 5 is rooted in the understanding