Recent progress in the development of vaccines for infants and children.

Infectious agents do not respect national or international boundaries. Attempts to prevent their spread, and the diseases which they cause, involve implementing vaccination as widely and as appropriately as possible. The principles of vaccination against infectious agents are now being applied to cancer and other non-infectious conditions. In order to understand where modern vaccinology is heading, it is necessary to first examine individual components. This brief overview examines the following: Streptococcus pneumoniae, Neisseria meningitidis, varicella zoster, measles, rotavirus, HIV, influenza, "emerging" viral infections and cancer.