Merck ($MRK) Animal Health announced on Sept. 16 that it has launched Porcilis Ileitis, the first-ever injectable vaccine to treat the form of ileitis caused by the pathogen Lawsonia intracellularis. The vaccine can be given to pigs as young as 3 weeks of age, and it provides 20 weeks of protection versus just 13 weeks from a frequently used water-administrated formulation, according to the company. Ileitis often goes unnoticed but can hamper daily weight gain by as much as 38% and feed efficiency by 27%, Merck said in a press release. The vaccine contains an adjuvant that Merck's scientists created specifically for pigs, which extends and strengthens the immune response. Release