Vaccinating

[ChrisB]

I have some questions on giving vaccinations that I've always wondered about. But first let me preface this by saying I "almost always" follow directions on the label. My questions are about booster shots; both 3-4 weeks after initial vaccination and the yearly booster shots.

1. I have been given a couple different reasons for needing the second round of vaccinations. One reason I've been told is that the cattle need the second shot to get full protection. Another reason I've heard is that some animals for some reason or other don't respond to the first shot and the second shot is to cover the 10-15% of the animals that may have 'missed' the first time. I've also been told that the initial shot doesn't do any good at all without the second shot. Does anybody know the scientific reason for the second shot?

Like I said I usually give the double vaccinations but I have at times missed the 3-4 weekd period for the second shot and those animals never did get the second shots. I didn't have any more problems with those calves than calves that were double vaccinated. Did I just get lucky?

2. Now for the specific reason for question 1. I had never had problems with footrot in the past until last fall. I think I ended up treating 20-25% of the cows. A neighbor also had an outbreak of footrot last fall and his problem started up again right away this spring. I had switched to a medicated mineral and hadn't had any problems for months and figured the new mineral had taken care of the problem. Well, last week I treated 2 cows again and I am wondering if this fall will be similar to last fall. I have since added organic iodine in with the mineral but also have decided to vaccinate the replacement heifers before turning them out with the cows. If I would have been on the ball, I would have done this a few weeks ago but at this point I am planning on just giving a single dose and then booster them next spring. Would I be wasting money by not giving the second shot in 3-4 weeks? Would they have some limited protection? After getting the annual booster next spring would they be considered to have full immunity?

 

[backhoeboogie]

I'm not a vet.

Mine get their second shot two weeks after the first. No antibiotics or other meds of any kind are used during this period. The second shot ensures they develop the proper level an antibodies.

Innoculations are cheap insurance. It seems some folks can be penny wise and dollar foolish. My grandaddy innoculated. My dad innoculated.

Herds of cattle border me on practically every side. I cannot control what goes on across the fence. Folks have opened my gates and let a neighbor's herd in with my cows when his cows were out. Bulls have jumped fences, cattle guards, and gates to get in with my heifers or cows. I've got a long list of such situations. Having my bunch innoculated sure gives me peace of mind.

Lots of folks around never give any shot of any kind. I've been on round-ups where cattle have never seen people before (and it aint no fun). You simply have to question the mortality rate for those situations.

Knock on wood, in all the years I have been around cattle, I have never dealt with foot rot. Maybe it is the climate or maybe I have been lucky. Anyway, I can't help you with that subject.

You might pm milkmaid or someone else with some vetinary training for technical details on innoculations or foot rot. My methodology for worming and innoculations works out for me so I stick with it.

 

[redcowsrule33]

. I have been given a couple different reasons for needing the second round of vaccinations. One reason I've been told is that the cattle need the second shot to get full protection. Another reason I've heard is that some animals for some reason or other don't respond to the first shot and the second shot is to cover the 10-15% of the animals that may have 'missed' the first time. I've also been told that the initial shot doesn't do any good at all without the second shot. Does anybody know the scientific reason for the second shot?

Depending on the vaccine, all of the above could be correct.

With a modified live virus (MLV) vaccine, you are injecting virus that has been treated such that it infects a cell and stimulates the immune system to attack it like it would an actual real viral infection, but it won't replicate further so it goes into neutral and doesn't cause a real infection. So in theory an animal shouldn't require a booster (and some vaccines are labeled this way) for at least a year after administration. The reason they minght tell you to booster an MLV vaccine if the animals were less than 6 months old is twofold. 1) maternal antibodies may be interfering in a small percentage and 2) the immune systems aren't fully "mature" until after they are 6 months old, so the response may have been poorer to the first vaccine.

Killed virus, killed bacterial , or bacterial toxoid vaccines do not cause a "fake" infection, but just presents the corpses to the immune system. It responds less aggressively if they are dead; it basically makes a note of what it just saw and moves on. However, if you re-present the corpses again, the immune system says "hey, I've seen this before, it must be a problem, let's react a bit more shall we" and you get the need level of response for protection. Because of this it tends to "forget" more quickly so the protection you get lasts for a shorter period. You also tend to get more reactions with this type of vaccines as it takes more virus/bacteria to get a response at all (you are injecting far larger amounts of foreign material than an MLV) and it reacts to the entire viral/bacterial cell, not just the few proteins on the outside that in a normal situation would be what the immune system looks for. This is why in most cases an MLV vaccine is superior to killed. However, in some cases they are not available or are not safe (such as pregnant animals)

Recombinant vaccines are very neat and safe, they cause a MLV-like reaction but without using any of the actual virus. To my knowledge, these are not yet available for food animals (no guess why, it would be far more convenient) but have been in the horse and pet markets for years.

Like I said I usually give the double vaccinations but I have at times missed the 3-4 weekd period for the second shot and those animals never did get the second shots. I didn't have any more problems with those calves than calves that were double vaccinated. Did I just get lucky?

If you used an MLV vaccine you were probably okay, otherwise just lucky. You do get some immune response to the first shot with the others but usually not enough to be protective.

Would I be wasting money by not giving the second shot in 3-4 weeks?

Yes.

After getting the annual booster next spring would they be considered to have full immunity?

No, tehy would be starting over with the initail series.

Hope this helps. PM me if it doesn't or you want more in-depth.

 

[ChrisB]

Thanks! That was a better response than I could have hoped for. I really appreciate you taking the time to type all that out.