- BCG vaccine is administered at inseion of deltoid on left shoulder - to allow easy identification of its scar Changes after BCG vaccination: - Intradermal injection using 26G needle raises 5-7mm wheal - It occurs by following sequence of events Bacilli multiply - form a papule - by 1 week which enlarges to 4-8 mm Ulcerates - by 5-6 weeks Heals by scarring - by 6-12 weeks Route of administration : intradermal