We have been vaccinating our calves for pinkeye, seems like it was working past several years. 

This summer have our fall calves in two groups in separate pastures 30 miles apart.  Both groups vaccinated in May then weaned in June.  Group A in a pasture with significant more flies, and trees/brush than group B.  Group B in pasture with running creek and pond for water, group A pond for water.  Group B did not consume any mineral in week before and several weeks after second dose of vaccines.  This was due to a salt water leak from oil production that was running into creek that cattle were drinking out of. These calves did consume some mineral during fenceline weaning when there only source of water was pond.  Around mid July calves in group B starting getting pink eye and treatment was started.  At least 60% of calves in this group have had and been treated for pink eye.  Group A has had no pinkeye issues.