Vaccination Decisions

Transcription

1 INFECTION CONTROL Understanding Those Valuable Vaccines 1 Miranda Spindel, DVM, MS Director of Veterinary Outreach Vaccination Decisions Why? Who? What? When? Where? Other 2 1

2 Vaccination plays a very valuable role in the prevention and control of major infectious diseases in cats and dogs The Veterinary Products Committee Working Group Report on Vaccines 3 Interact with us! You can change the color of your checkmark 4 The arrow or pointer tool displays your name Click next to the rectangle to find a Click next to the eraser to remove your pointer or checkmarks 2

3 Mythbusters. In most shelters, fosters, rescues TRUE FALSE 1. Injured or sick animals should generally be vaccinated 2. Vaccinating after stray holding times is effective 3. Vaccines are going to cause disease in some animals 4. The risk of side effects from vaccinating outweighs the benefits 5. Immunity can begin developing within hours of receiving a vaccine 5 Why Vaccinate? Critical part of any wellness program Primes the immune system for a future rapid response May prevent life-threatening disease Can benefit population health and welfare 6 3

4 Why Vaccinate? Prevent some fatal diseases Rabies Canine Parvo Virus Feline Panleukopenia Canine Distemper Virus Clinical rabies 7 Why Vaccinate? Prevent or limit the effects of other diseases Calici C i virus Bordetella bronchiseptica Feline Herpes Virus Chlamydophila felis Clinical URI 8 4

5 How Do Vaccines Work? Innate Immunity Primitive Pi ii No memory Fast response Multiple Components Anatomic barriers Physiologic y g barriers Chemical factors Endocytosis/phagocytosis 9 How Do Vaccines Work? Acquired Immunity SophisticatedS i d It remembers Takes time for response Two arms B cells (antibody mediated) T cells (cell mediated) Continually develops 10 5

6 How Do Vaccines Work? Antigens Material that causes immune response Bacteria, viruses, pollens, allergens Antibodies Proteins that form after the body s first exposure to an antigen Bind to antigens so they can be identified by the immune system as foreign Stay in the body for a long time This is the body s memory for disease 11 How Do Vaccines Work? Natural infection & recovery strong acquired immunity Vaccination stimulates acquired immune system never as strong as natural exposure 12 6

7 How Do Vaccines Work? Vaccines are not guaranteed disease protection Good husbandry is equally important!!! Must be used with other wellness measures Sanitation Population control Sometimes vaccines fail 13 How Do Vaccines Work? Why might a vaccine fail? Animal s immune system does not respond Improper handling, timing, administration etc. Already infected when vaccinated Vaccine not protective against disease encountered 14 7

8 Vaccines Are NOT instant immunity for every animal NOT antibodies NOT guaranteed disease protection 15 Vaccines Are Agents that trigger protective immune responses Able to prevent some diseases Able to limit severity of other diseases Ways to limit overall disease and severity in a population One of the MOST important wellness tools for homeless animal & community health 16 8

9 17 Canine and Feline Vaccine Guidelines American Association of Feline Practitioners (AAFP) American Animal Hospital Association (AAHA) Perhaps the most noteworthy addition is a separate set of recommendations created for shelter facilities 18 9

10 Definition of Shelter An animal shelter is a holding facility for homeless animals, usually awaiting adoption, rescue or reclaim by owners. In general, animal shelters are characterized by a random source population with a largely unknown vaccination history, high population turnover, and a significant potential for infectious disease risk. AAHA Guidelines 19 Vaccination Decisions Vaccination decisions must always be made on an individual basis, based on risk and lifestyle factors AAHA Guidelines 20 10

11 Vaccination Decisions Goals Vaccinate the greatest number of at risk animals Vaccinate no more frequently than necessary Vaccinate against only infectious agents for which risk of exposure is real Vaccinate only when benefits of procedure outweigh risks Vaccinate appropriately for public health protection 21 Vaccination Decisions Similar goals, but different risks and lifestyles 22 11

12 Vaccination Decisions Owned Animals Homeless Animals Many animals will be vaccinated lifelong Disease risk is lifestyle dependent Goal is to minimize frequency and risk of side effects while ensuring immunity Many animals naïve Disease exposure risk is usually high Goal is rapid onset of adequate immunity to minimize risk of infectious disease developing 23 Let s Get to Know Each Other 24 12

13 Vaccination Decisions Shelters are unique high risk environments Considerations are different than for owned pets There is no universal protocol for every situation Vaccination is a medical decision and procedure Risk:benefit for each animal and the population must be weighed in every protocol 25 Vaccination Risks Liability issues know the law where you are In animals not owned by shelter Vaccinating by shelter staff Resource allocation/financial investment Vaccines can cause signs of illness Improper administration Adverse events undesirable occurrences 26 13

14 Adverse Events Local reaction injection site sore Fever Anorexia Lethargy Immune reaction type I-IV vomiting/diarrhea anaphylaxis hives/swelling/itching anemias etc Although not common every shelter should have a plan ready for managing vaccine associated adverse events. 27 Who Weighing the Risk:Benefit Ratio ALL animals over 4 weeks of age few exceptions Risk of vaccinating Already vaccinated Vaccine failure Adverse event Benefit of vaccinating Prevent/limit disease Individual Population 28 14

15 Who Vaccinating All Animals Over 4 Weeks Concept of herd immunity It is more difficult to maintain infection when large numbers of a population are immune Factors that affect vaccine response Age maternal antibody Health Status sick, injured, stressed Genetics some animals don t respond 29 Age Factors Overcoming Maternal Antibody Antibodies A passively passed in mother s milk (first 24 hours) Levels dependent on dam s immunity and neonate s health Protect against infectious disease Maternal antibodies neutralize vaccines Maternal antibody wanes by around 3 months of age (most susceptible time) Exact time that levels drop is different in every animal It s a race between vaccine response and disease 30 15

16 Age Factors Window of susceptibility to disease Window of Susceptibility Maternal Antibody Full Immune Competence Birth (18-20 weeks) 4 wks Vx every 2-3 weeks 16 wks 31 Medical Factors Nursing? Pregnant? Sick? Injured? No additional risk in nursing Pregnant Risk may outweigh benefit Many shelters vaccinate & spay Case by case w/ DVM Sick In general, vaccinate Temperature > may fail Injured In general, vaccinate Risk of vaccinating Already vaccinated Vaccine failure Adverse event Benefit of vaccinating Prevent/limit disease Individual Population 32 16

17 Animal Status What about waiting to vaccinate until after stray period? Not recommended Exposure likely prior to vaccination What about just vaccinating adoptables? Not recommended Only viable if populations are strictly isolated Risky Cost savings may not be worth it Risk of vaccinating Already vaccinated Vaccine failure Adverse event COST Benefit of vaccinating Prevent/limit disease Individual Population Expense of outbreak/illness 33 Which Animal to Vaccinate? 4 month old Injured, stray 1 year old Feral 8 weeks old Friendly, healthy years old Friendly 1-2 years old Friendly, nursing 8 weeks old URI 17

18 Ideally. Isolate me! Isolate me! 4 month old Injured, stray 1 year old Feral 8 weeks old Friendly, healthy Isolate me! years old Friendly 1-2 years old Friendly, nursing 8 weeks old URI What Weighing the Risk:Benefit Ratio Vaccinate against diseases of greatest significance core vaccines Risk in using non-core: Cost Adverse events Benefit of core: Rapid immunity Lifesavingg 36 18

19 Shelter Vaccine Choices Types of Vaccines & Routes of Administration Modified Live Vaccines Subcutaneous Topical (intranasal) Killed Vaccines Recombinant 37 Shelter Vaccine Choices Modified Live Vaccines One dose can provide some immunity Fast protection Overcomes maternal antibody well Can cause mild signs of disease Poor choice in pregnant, immunocompromised Can interfere with diagnostic testing Need careful storage and handling 38 19

20 Shelter Vaccine Choices Killed Vaccines Stable when stored Do not cause clinical signs More frequently associated with adverse events Require time for immunity (usually weeks) 39 Shelter Vaccine Choices Recombinant vaccines Fast F t protection ti Safe in young animals Overcome maternal antibody Do not cause clinical signs Expensive Single agent protection 40 20

21 Shelter Vaccine Choices Intranasal vaccines Always modified live Stimulates S local immunity Rapid onset of protection Safe for very young animals No maternal antibody interference Herd immunity possible Subcutaneous vaccines Ease of administration Reversion to virulence impossible 41 Shelter Vaccine Choices Intranasal vaccines Can be difficult to administer Sometimes S cause mild clinical signs Risk of inadvertent injection Packaging can minimize risk Poor panleukopenia protection Subcutaneous vaccines Slower onset of immunity it Booster required 42 21

22 Shelter Vaccine Choices Choose a Modified Live Virus vaccine: Panleukopenia Parvo virus Distemper Feline URI vaccination choices are variable Canine URI vaccination Intranasal trivalent recommended 43 Shelter Vaccine Choices CANINE 1. Recommended deemed most important for all dogs housed in shelter environments 2. Optional administered selectively based on geographic and lifestyle exposure and assessment of risk:benefit 3. Not recommended 44 22

23 Shelter Vaccine Choices CANINE 1. Recommended (for all!) Distemper Adeno-2 Parvo Parainfluenza Bordetella bronchiseptica 45 Shelter Vaccine Choices 2. Optional Rabies 3. Not recommended Lyme Lepto Adeno-1 1 Giardia Corona CANINE 46 23

24 Vaccinate Me! Lepto Canine influenza virus 47 Vaccinate Me! Lepto Canine influenza virus 48 24

25 Shelter Vaccine Choices FELINE 1. Core recommended for all cats 2. Non-core administered to cats in special risk categories 3. Not generally recommended little or no indication for use 49 Shelter Vaccine Choices FELINE Core Herpes Calici Panleukopenia Rabies (at discharge) Non-core Chlamydophila felis Bordetella bronchiseptica Not recommended FeLV FIV Giardia FIP 50 25

26 Vaccinate Me! Lepto FIV 51 Vaccinate Me! Lepto FIV 52 26

27 When Weighing the Risk:Benefit Ratio Vaccinate on or before entry into the population Risk of vaccinating Already vaccinated Adverse event Vaccine failure Cost Benefit of vaccinating Immunity begins to develop immediately 53 Vaccine Schedules Assume adults to be unvaccinated FVRCP and DA2PP Administer one dose on admission Repeat a second dose at an interval no less than 2 weeks apart (2-3 weeks later) Rabies One dose, usually on exit. Some long term facilities administer on entry

28 Vaccine Schedules Youngsters 4-20 weeks Ideally house out of a shelter population Vaccinate frequently to catch the window of susceptibility FVRCP and DA2PP Administer one dose on admission Repeat every 2-3 weeks until weeks Rabies One dose at legal age, usually on exit, sometimes during stay. 55 Vaccine Care, Handling & Administration Mishandling vaccines can cause them to fail Always read and follow manufacturer label directions Store properly until expiration date then discard Refrigerate do not freeze Protect from sunlight Rotate stocks when new shipments arrive Do not reconstitute and store Do D not leave out on icepacks all day 56 28

29 Vaccine Care, Handling & Administration Prepare and administer vaccines properly Best to use individual vials vs. multidose stocks Mix with proper diluent for batch Do not split doses or mix vaccines Give by proper route Use sterile technique Vaccinating should be a two person task Administer i i t a full dose Clean up any spills with bleach or alcohol Report mistakes 57 Vaccine Care, Handling & Administration Document vaccination Type of vaccine Date Who administered Anatomical location Manufacturer Dose volume Expiration date Serial Number Peel label and place on medical record 58 29

30 Where? Administer in standard anatomical location Risk of random site: Adverse event hard to identify Benefit of known site: Documentation of adverse event possible 59 Where? Da2PP/FVRCP right forelimb Rrrabies rrright rrrear Llleukemia (cats) llleft rear 60 30

31 Other Important Considerations Immunity in the community is very important Work with your regular DVM to vaccinate your animals Encourage adopters to seek post-adoption follow-up 61 Summary 62 Why? Vaccination plays a very valuable role in the prevention and control of major infectious diseases in cats and dogs Who? ALL animals over 4 weeks of age few exceptions What? Vaccinate against diseases of greatest significance core vaccines When? Vaccinate on or before entry into the population and provide boosters Where? Administer in standard anatomical location, using proper care and handling Other 31

32 Discussion 63 Resources American Association of Feline Practitioners (AAFP) American Animal Hospital Association (AAHA) ASPCApro Website Shelter Medicine Shelter Medicine Guide pp

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