There are many difficult decisions to be made when changing the brand or manufacturer of a vaccine line. The real comparisons can be made when you know what specific diseases you need to vaccinate for in your herd, whether to use a modified live, killed, or combined program and rate the effectiveness of your original program. Knowing this will help your herd veterinarian determine where to come in with different products. This is all assuming the previous vaccines were purchased, stored, handled administered properly and timely in the past to all necessary cattle in your herd.
If it is a case where your herd health veterinarian is changing lines it could be for several reasons, only one of which might be the efficacy of the product. Other reasons are availability, cost, dosage formulation, number of doses per bottle and even service provided by the pharmaceutical company.
I have known clinics changing trade names simply based on route of administration. If two vaccines are equal and one is approved to give subcutaneously that may be a more desirable route and supports the Beef Quality Assurance program. Sometimes newer products may protect against a broader range of bacteria or viruses, making them more desirable. Vaccines that provide greater protection in fewer shots may be favoured as well. More shots simply mean more labour and stress (another needle poke) on the calves. The intranasal route eliminates the needle but may have a shorter duration. These are all decisions you and your veterinarian need to make.
Read the fine print
Knowing which vaccines do what requires essentially reading the fine print and you will find most pharmaceutical companies have pretty good spreadsheets indicating which vaccines protect against which diseases. Pay close attention, as vaccines can be very close in protection yet one organism’s protection may be missing. This is where it best to consult with your veterinarian in case there are any differences in coverage.
Once you’ve determined control of all the diseases are the same, then there is the question of whether you can carry on boosting the same way you have in the past. Just because you have changed vaccines does not necessarily mean you need to start a vaccine program all over again — in fact the opposite is the case.
Vaccines in general stimulate the body to produce antibodies or protection against a specific disease. If you come in with a different vaccine — as long as immunity is there and the diseases are the same in the new vaccine — it should booster the previous vaccine response. This is much the same principal as if a natural viral infection came through it would essentially stimulate the immune system the same way.
Follow label directions and if the previous vaccination program has worked well and you trust the protection it provided, then boostering with a comparable product should work fine.
My only caution is if killed vaccines were previously given at the recommended rate, then modified live vaccines or different killed products can be followed up with. My personal preference is using modified live vaccines for the longer duration of immunity but some vaccines such as the footrot vaccine only come as a killed product.
Reasons to change
Starting over with a new line may be recommended in several instances such as the acquisition of new stock with a sketchy vaccination history or if a year has been missed meaning now it is two years between vaccinations. Vaccinations can be missed because cattle escaped the chute, dosage was not calculated or automatic syringes were not working properly. Whatever the reason treatment was missed, it is important to start the vaccination program over again. If an additional organism (virus or bacteria) has been added into the program it is highly likely it will need to be boostered the first time.
The bottom line is if you are changing vaccines and your previous one gave protection and all the antigens (organisms) are the same you should be protected with using the new vaccine. If new protection has been added it may need to be boostered, but these are all good questions to pose to your veterinarian so gaps are not created in the new vaccination program.
As we all know, vaccination is common and it is far better to prevent disease than treat it. It also allows more cost savings in using antimicrobials as well. Sparing usage helps prevents antimicrobial resistance from building as quickly.
These are all good reasons to work with your veterinarian yearly on the most updated, least stressful most comprehensive and efficacious vaccination program necessary for your farm and management style. Pharmaceutical companies will continue to improve vaccines making them more efficacious, broad spectrum and less reactive, coupled with in some cases easier means of administration. The future looks promising to use vaccination to improve the health of our cattle herds and reduce antimicrobial usage.