This resource was fully reviewed and updatedA member of The Open Sanctuary Project’s staff has given this resource a full review and provided updates where necessary. in preparation for veterinary review. It was originally published on September 11, 2020.

When it comes to keeping our residents healthy, we have many tools in our toolkit. From the diet and living spaces we provide to the daily care they receive, each tool plays an important role in promoting health and protecting them from disease. In addition to these tools, for some diseases, vaccination plays a crucial role in prevention. When creating a vaccination program for your residents, we always recommend working with your veterinarian to determine what is most appropriate for your residents.

Vaccines Are Just One Part Of The Equation
While this resource focuses on the role vaccinations play in protecting residents from disease, we’d be remiss if we didn’t stress the importance of creating a comprehensive biosecurityMerck Veterinary Manual defines biosecurity as ”the implementation of measures that reduce the risk of the introduction and spread of disease agents [pathogens].” plan with your veterinarian. In addition to considering the role of vaccination in protecting residents from disease, a biosecurity plan will include numerous additional measures that work together to offer more complete protection. Check out our biosecurity series here.

Understanding Vaccines

Before working with your veterinarian to create a vaccination program for your residents, it’s helpful to have a basic understanding of how vaccines work and the different types of vaccines and products available.

How Do Vaccines Protect Residents From Disease?

Vaccines teach the immune system to recognize and respond to specific pathogens (viruses or bacteria) or, in some cases, toxins produced by a pathogen. This is accomplished by introducing a harmless version or small piece of the disease-causing agent, which triggers an immune response without causing disease. Immune cells are activated, and antibodies are produced to fight off the threat. This process takes time and sometimes requires an additional dose (or “booster”) of the vaccine – immunity is not immediate following vaccination. If an individual is exposed to the disease-causing agent too soon after vaccination, they will not yet be protected from the disease.

However, when a fully vaccinated individual is exposed to the disease-causing agent in the future, their immune system will recognize and remember the threat and will be able to mount a faster response than if they had not been vaccinated. In some cases, their immune system will be able to destroy the disease-causing agent before it has the chance to cause disease. Other times, vaccination may lessen the severity of the disease. In addition to the direct benefit to your residents by either preventing or lessening the severity of disease, an appropriate vaccination program can also reduce the need for antimicrobial treatment, thereby slowing the rate of developing antimicrobial resistance.

The Main Types Of Vaccines

According to the American Society For Microbiology, there are four main vaccine types used in veterinary medicine: live-attenuated, inactivated, toxoid, and recombinant vaccines. 

Live-Attenuated Vaccines

Live-attenuated vaccines (also called live, modified live, or attenuated vaccines) contain live, intact pathogens that have been weakened (attenuated). Live-attenuated vaccines are carefully created and tested to stimulate a strong immune response without causing disease. For safety reasons, some viruses cannot be given as live-attenuated vaccines because of the risk of the intact pathogen causing disease and the risk of infecting humans with the live-attenuated vaccine. 

Protective immunity for live-attenuated vaccines lasts longer than other vaccine types and is often achieved with just one dose. Some live-attenuated vaccines may cause a brief period of pathogen shedding in individuals following vaccination. If not everyone in a group will be vaccinated, your veterinarian may recommend separating vaccinated residents from non-vaccinated residents for a few weeks following administration to prevent possible disease spread.

Live-attenuated vaccines may not be recommended for individuals who have a weakened immune system. This may include individuals with certain health conditions, individuals on certain medications, and individuals who are pregnant. Always consult with your veterinarian for specific guidance.

Because the level of attenuation is critical to ensure proper immunity without risk of disease, live-attenuated vaccines should only be used in species for which they have been tested and approved. The level of attenuation required to produce adequate immunity in one species may not be appropriate for another. Overattenuation could fail to stimulate a sufficient immune response, and underattenuation could result in disease.

Live-attenuated vaccines must be stored and handled very carefully and discarded soon after opening or reconstitution. Always follow label instructions. 

Inactivated Vaccines

Unlike live-attenuated vaccines that contain live pathogens, inactivated vaccines (also called killed vaccines) contain whole pathogens that have been killed or inactivated, rendering them incapable of causing disease or spreading between individuals. Because inactivated pathogens do not trigger the same immune response as attenuated pathogens, inactivated vaccines often rely on adjuvants (substances within the vaccine formula which will enhance the immune response) to increase their efficacy. The level of immunity produced by these vaccines is weaker and not as long-lasting as live-attenuated vaccines. As a result, initial vaccination often requires multiple doses, and subsequent boosters are necessary to provide ongoing protection. 

Because of the addition of adjuvants and the need for multiple or higher doses of antigen, inactivated vaccines may carry a higher risk of localized inflammation and hypersensitivity. 

While all vaccines must be stored and handled properly to ensure their efficacy, inactivated vaccines are generally more stable than live-attenuated vaccines.

Toxoid Vaccines

Whereas most vaccines protect against specific pathogens, toxoid vaccines provide protection against the toxins produced by pathogens, rather than against the pathogen itself. To do this, they include inactivated toxins to stimulate an immune response to that toxin. Compared to other types of vaccines, toxoids typically offer the shortest duration of protection.

Recombinant Vaccines

Recombinant vaccines are made by inserting a small piece of a pathogen’s DNA into manufacturing cells, which then create large quantities of antigens. These antigens are then purified and used in the vaccine. Recombinant vaccines cannot cause disease because they only use a piece of the pathogen’s DNA rather than the whole pathogen. They are also less likely to cause systemic or localized reactions compared to live-attenuated or inactivated vaccines.

Types Of Vaccine Products

In addition to different types of vaccine technology (described above), there are also different types of vaccine products. Vaccines offer targeted protection – some vaccines are designed to protect against one specific strain of a pathogen (monovalent), others protect against two or more strains of the same pathogen, and some vaccines offer protection against two or more different pathogens or diseases (bi- or multivalent). Depending on the pathogen/disease you need to vaccinate for, you may find that there are different types of products available (e.g., there may be a monovalent vaccine that only offers protection against that specific pathogen strain, as well as one or more combination products that protect against that and other diseases). Combination products are especially useful when individuals need to be vaccinated against multiple pathogens. 

Importance Of Proper Storage And Handling

Improper storage and handling can have an adverse effect on the safety and efficacy of vaccines, so be sure to adhere to each product’s specific label instructions. Failing to maintain proper storage conditions regarding temperature and protection from sunlight, administering vaccines incorrectly, and using products past their expiration date or too long after reconstitution can reduce efficacy, lead to vaccine failure, and increase the risk of adverse reactions. Similarly, failing to use aseptic technique when handling and administering vaccines can increase the risk of adverse reactions.

Creating A Vaccination Program For Your Residents

Regardless of the species you care for, it is crucial to work with an experienced veterinarian in your area when creating a vaccination program for your residents. They can help determine which vaccinations your residents should receive based on a number of factors, including their risk of disease, the consequences of disease, and the safety and efficacy of available vaccines. They can also make recommendations about which specific products to use, the most appropriate vaccination schedule for your residents, and steps you can take to reduce the risk of adverse reactions.

Core vs. Risk-Based Vaccinations

When determining what vaccinations your residents should receive, one consideration (among many) is whether the vaccination is considered a core vaccination or not. Core vaccinations are universally recommended for a particular species unless there is a medical reason not to vaccinate someone. Risk-based vaccinations (or non-core vaccinations) are just that: vaccinations that are recommended based on risk factors specific to the individual (and in some cases, based on the risk of your residents spreading zoonotic diseaseAny disease or illness that can be spread between nonhuman animals and humans. to the humans they come into contact with). Your veterinarian will consider a wide range of factors when determining if they should recommend a risk-based vaccination. These factors include your region, climate, physical location, setup, resident population, and the activities your sanctuary participates in. You can read more about some of the factors that can impact your residents’ risk here. Because the risk of some diseases varies from region to region, it’s essential to work with a veterinarian in your area to determine which vaccinations your residents should receive. 

As mentioned above, the activities your sanctuary participates in can impact whether or not a particular risk-based vaccination is recommended for your residents. For example, vaccinations that prevent reproductive issues such as abortion and stillbirths may be universally recommended to breeders and farmers in your area, but may be deemed unnecessary for your residents (because sanctuary residents should not be allowed to breed). Similarly, certain risk-based vaccines may be recommended if your sanctuary engages in rescue activities or otherwise welcomes new residents regularly (which could be a source of infectious disease introduction to other residents). There may also be risk-based vaccinations that are strongly recommended if your sanctuary regularly welcomes visitors or otherwise engages in activities where residents come into contact with humans other than their caregivers. 

You can learn more about vaccinations that may be recommended for specific species by following the links below:

• Cows
• Horses
• Donkeys
• Llamas
• Alpacas
• Pigs
• Sheep
• Goats
• Rabbits

What About Vaccinations For Farmed Bird Species?
Compared to the mammalian species typically cared for at farmed animal sanctuariesAnimal sanctuaries that primarily care for rescued animals that were farmed by humans., avian species are less routinely vaccinated, but that’s not to say that vaccination is never recommended or appropriate for avian sanctuary residents. We plan to discuss the topic of vaccinations for avian residents in a future resource, so stay tuned! As with creating vaccination programs for mammalian species, veterinary involvement is crucial when determining which, if any, vaccinations your avian residents should receive.

Make Sure You Understand Your Veterinarian’s Recommendations

As mentioned throughout this resource, we encourage folks to work with their veterinarian to determine which, if any, vaccinations their residents should receive, but it’s equally important to make sure you understand the reasoning behind their recommendations. This will allow for further conversation, if needed, and will allow you to raise any concerns you may have. When discussing specific vaccinations with your veterinarian, you may need to ask some or all of the following questions:

• What disease or disease-causing agent does vaccination protect against?
• Is this a core or risk-based vaccination for the species in question?
• What types(s) of vaccine(s) is/are available (e.g., live-attenuated, inactive, etc.)?
  • If more than one is available, which type does your veterinarian recommend and why?
• Is there a product labeled for use in the species in question, or would it require extra-labelExtra-label use means that a drug is used in a way other than what is described on the label or package insert. If a drug is used in a different species than what it has been approved for, this is extra-label use. Other examples include using a drug to treat a different condition than it is approved for or administering it in a different way than the directions describe. Extra-label drug use can only occur within the confines of a valid veterinarian-client-patient relationship. use?
  • If extra-label use is required, what evidence is there about safety and efficacy?
• What are the benefits of vaccination?
• What risks would residents face if they are not vaccinated?
• What risks are associated with vaccination (and with the specific product recommended)?
  • What types of adverse reactions are common? 
  • What is the likelihood of more severe reactions? Are there medications we should have on hand to respond in the event of a severe reaction (e.g., epinephrine)?
  • Are certain individuals more at risk of adverse reactions?
  • What can we do to reduce the chance of adverse reactions?
  • Can vaccination cause disease or expose others to disease?
  • Will vaccination interfere with disease screening tests? What would be the implications of a vaccinated individual testing positive for the disease in question?

Create A Vaccination Schedule And Written Vaccination Protocols

Once you’ve worked with your veterinarian to identify which vaccinations, if any, your residents should receive, you’ll want to also work with them to create a vaccination schedule for your residents and accompanying written vaccination protocols for each species you care for. If non-veterinarian sanctuary personnel will be responsible for administering vaccinations, your protocols will need to contain all the pertinent information necessary to do so. Please note that some vaccines can only be administered by a licensed veterinarian. 

Your written protocols should include:

• Which product is used (including the manufacturer of the vaccine, as some manufacturers produce vaccines via different methods than others)
• The timing and frequency of vaccinations (for the initial vaccination series as well as revaccination)
• Any age restrictions or other restrictions
• Whether or not veterinary assessment is recommended before administration for everyone, or only for individuals who are currently dealing with or recovering from a health challenge
• Steps to take to reduce the risk of adverse reactions
• Signs of adverse reactions to watch for following vaccination, and what to do if noted
• Human safety considerations

Vaccination Recordkeeping
Be sure to keep thorough records of all vaccines administered. You can download our Resident Vaccination Log here!

The right vaccination program can play an important role in protecting your residents from certain diseases. If you have not already done so, be sure to have a conversation with your veterinarian about the best vaccination strategy for your residents!

SOURCES:

Vaccine Overview And Types | American Animal Hospital Association

Types Of Vaccines For Animals | Merck Veterinary Manual

Types Of Vaccine | University Of Oxford

Vaccine Storage And Handling | American Association Of Equine Practitioners 

Animal Vaccine FAQs: Protecting PetsAnimals who spend regular time with humans in their home and life for companionship or human pleasure. Typically a small subset of animal species are considered to be pets by the general public., LivestockAnother term for farmed animals; different regions of the world specify different species of farmed animals as “livestock”. and Wildlife | American Society For Microbiology (Non-Compassionate Source)

Animal Vaccines – Principles, Types, and Important Points to Know | University Of Florida IFAS Extension (Non-Compassionate Source)

Non-Compassionate Source?
If a source includes the (Non-Compassionate Source) tag, it means that we do not endorse that particular source’s views about animals, even if some of their insights are valuable from a care perspective. See a more detailed explanation here.