ABSTRACT

Prophylactic vaccination is the most effective strategy to control any infectious disease epidemic. It has served to eradicate smallpox and significantly reduce morbidity and mortality due to countless other childhood diseases including polio, pertussis, and measles. Infectious pathogens which induce a latent phase, such as Mycobacterium tuberculosis, will be considerably more difficult to eradicate. Bacille Calmette–Guerin (BCG) is a live attenuated vaccine that was developed at the Institut Pasteur in Lille, France by Albert Calmette and Camille Guerin. BCG remains one of the most widely used vaccines globally, having been administered to over 4 billion people. It has a very well-established safety profile with correct intradermal administration on the upper arm generally resulting in a local reaction of a small pustule followed by a small scar. BCG lymphadenitis is characterized by enlarged ipsilateral axillary nodes, and is most frequently observed in children under the age of 6 months.