Some people give a shot of antibiotics when they bring "stressed" cattle home from a sale barn.
I don't believe in giving antibiotics unless they need it.
I would recommend giving the OPEN cattle Modified Live Vaccines - IBR, BVD, PI3, BRSV (BoviShield Gold or Vista) You really need to check with a vet to see what is recommended for your area, or with the local extension office. MLV do not need boosters except possibly the BRSV (BoviShield Gold BRSV - but Vista does not need a booster) But, I would give a 2nd shot of MLV about 4 weeks later to make sure they all have 100% coverage (only about 80% get full coverage with 1 shot). MLV is CHEAPER than KILLED, and it gives (at least) 1 full year protection (possibly life).
For anything you purchase BRED, you can only give them a KILLED vaccine. Killed vaccines must have a booster within a specific time period (usually 2-4 weeks). If you don't give the booster, you might as well not give anything. Killed vaccines do not give very good coverage, and generally only good for 6 months. AFTER CALVING, I would give all cows a MLV shot PRIOR to getting rebred. Then, calves can receive a MLV while they are still nursing dam.
BE SURE TO READ LABELS - this info varies with different vaccines.
We vaccinate calves for:
IBR, PI3, BVD, BRSV, Pasturella, Lepto 5 (one shot) Vista
Clostridials, Homopholus Somnus - BarVac 7 Som