Immunizations are vital for improving public health and decreasing healthcare costs.

• The details of vaccine science or all vaccine-preventable diseases are beyond the scope of this chapter.

​Influenza (Flu)
Influenza, also called the flu, is a common but sometimes serious viral infection of your lungs and airways. It can cause congestion, fever, body aches, and other symptoms.

Meningitis

• Bacteria first attach themselves to pharyngeal epithelial cells, then are phagocyte into host’s bloodstream.
• CNS bacterial pathogens have extensive polyacrylamide capsule resistant to eutrophic phagocytes and complement optimization.

​Typhoid
Incidence of typhoid and paratyphoid among UK travellers visiting friends and relatives in the Indian subcontinent is increasing, according to the Health Protection Agency.