... fighting infections, have three main types; macrophages, B-lymphocytes and T-lymphocytes. Macrophages are cells that engulf and break down the invading bacteria or virus, leaving behind antigens which are sections of the disease-causing organism. These antigens are still registered as harmful to the body and so the ... effective during which it enters your body (11). Although there are many chemicals used in vaccines, they serve a purpose in the protection they give and the vaccines are tested many times to ensure the safety (14). As an example, formaldehyde is present in vaccines. Howe...

• Word Count: 6040
• Approx Pages: 24
• Has Bibliography
• Grade Level: Undergraduate