15 - Vaccines and their use

Question 1

What is immunocastration? Who it is used for

Answer 1

Vx for pigs against GnRH (gonadotropin released hormone)
Contains GnRH linked to a carrier to stimulate an immune reaction
antibodies bind to animals GnRH, block its activity, so no FSH or LH prod to stim the testes
two doses, starting at 12 weeks
accidental injection to self (no risk for first occasion)

Question 2

What four things make a core vaccine, a core one?

Answer 2

Going to be effective, small adverse reaction risk, for severe common dz’s, and does the benefit of vx’s very likely to exceed risks?

Question 3

What are examples of core vaccines in dogs?

Answer 3

DA2PP
Rabies

Question 4

What are some optional core vaccines? What does use depend on? Examples in dogs?

Answer 4

use depends on Location and spikes in dz prevalence
Dogs ex: bordetella bronchiseptica, canine enteric coronavirus, borrelia vaccine

Question 5

What are the 4 common routes of vaccine administration?

Answer 5

IM, SQ, IN, orally

Question 6

What are the advantages, disadvantages and precautions of systemic vaccine administration?

Answer 6

IM and SQ
advan: reliable administration + systemic (IgG) immunity
Disad: need a needle, no (little) IgA immunity
Precaution: clean bottle cap, new needle/syring/per animal

Question 7

What are the advantages and disadvantages of mucosal vaccination?

Answer 7

IN - orally (buccal)
advantages - Local and systemic immunity (IgA and IgG) and no needle
disadvantages - head restraint, variable vx administration
usually need a MLV

Question 8

What is the difference between single and multiple antigen vaccines?

Answer 8

convenient and not usually an issue, less pokes

Question 9

What might determine vaccination schedules?

Answer 9

priming dose, then 2nd 21-28days layer for a max immunity about 2-3wks later
live vx’s or depo vx’s may only require one injection
revax (booster) 1-3yrs

Question 10

In terms of vx schedules, what follows after the priming dose?

Answer 10

initially no Ab -antigen has to be phagocytosed by dendritic cells and presented to lymphocytes -? lymphocytes then multiple and make memory cells/become plasma cells to prod IgM

Question 11

How might maternal immunity and vaccination affect neonates?

Answer 11

passive Ab very successful vx of neonates. Maternal Ab’s degrade 50% every 2wks. neonates given multiple priming vx’s (puppies @ 8, 12 and 16wks) which allows u to catch patient when Ab status low + vx effective.
OR delay until Ab gone (in puppies/kittens, colostral immunoglobulin gone by 12wks, rabies given after 12wks) in foals/calves >6mo

Question 11

Why might a vaccination fail?

Answer 11

incorrect storage or administration
inability to respond - colostral antibody neutralizes vx, genetic differences, immune suppression (parasites, malnourished, viral infections), vx at time of neuter does not alter response in kittens

Question 12

What are high antibody levels associated with in terms of response to vaccination

Answer 12

strongly antigenic vx’s
sm dogs
first vx as a younger adult (3-4yrs of age)
certain breeds

Question 12

What percent of dogs have adverse vx reactions? What makes this risk higher?

Answer 12

0.4% risk
Higher if small, multiple vx’s given, repeated vaccination and if they are neutered

Question 13

What are some common adverse reactions of vaccinations?

Answer 13

Lethargy/fever, inflammation at injection site, inappetence, pruritis, GI signs - vomiting and diarrhea, hives or facial swelling

Question 14

What are some signs of pain at time of injection?

Answer 14

Mild discomfort is expected but is a problem if its severe
May bite vaccinator, discomfort when being pet, struggling may increase tissue destruction and increase pain and inflam, reduce by considerate handling, environment, rewards, distraction

Question 15

When might inflammation following vaccination occur, what are the signs?

Answer 15

1-7 days after vx
Warmth, swelling, edema, fever, usually subside but use NSAIDs on severe cases, may abscess, and has a possibility of abortion

Question 16

What are some hypersensitivity reactions that might occur following vaccinations?

Answer 16

Anaphylaxis rare but serious
associated w/ repeated vaccination - Killed (bc of repeated injection of Ag)
Type I occurs within minutes - hx of asthma/allergy inc risk in people, mediator (histamine from mast cells IgE), signs are weakness, V/D, increased RR
Type III - Ag-Ab complexes deposit in tissues, 2-3wks after infection/vx, signs: intense local inflam, purpura, blue eye, alopecia
Type IV: T-cells and macrophages, granuloma at injection site (may abscess, more common w/ depot (oil) vx’s, takes 12-72 hrs to develop

Question 17

Why might vx induced autoimmune dz occur?

Answer 17

Rare
when the vx has grown on cell line of the same species plus adjuvant

Question 18

What is vx induced hypertrophic osteodystrophy?

Answer 18

Rare condition - lg and giant breed puppies vx’d w/ MLV distemper vx (weimaraner)
starts within 10d, treat w/ corticosteroids, pre-existing immunodeficiency
May need to only use killed vx’s for them

Question 19

What are injection site carcomas in cats?

Answer 19

can occur following any injection in cats
Some vx’s have a higher association rate
Rate: 1/10,000 vx’s
Multiple vx administration
vx’s w/ strong adjuvants
middle aged to older cats often at site of injection
challenging to treat - very invasive tumor

Question 20

What are some adverse consequences of vaccination?

Answer 20

errors in vx manufacture - poor attenuation of vx or contamination (some original sheep vx’s were contam w/ scrapies)
Teratogenic - live bluetongue vx’s - fetal abnormalities in sheep
Some vx’s are mildly immunosuppressive - some parvovirus vx’s/polyvalent vx’s will cause lymphocyte #’s to dec temporarily

Question 21

What can we do to prevent adverse vaccine reactions?

Answer 21

Always obtain a history - Any previous problems, can you switch types of vaccines (previous lumps associated with vaccines (usually rabies vx’s)
document details of vx reactions on patient’s file
pre-treatment w/ diphenhydramine or NSAID prior to vx in animals with a known hx or vx reactions
don’t over vaccinate
recommend close monitoring for 20 min following vaccination - to detect anaphylaxis

Question 22

What should we do to treat anaphylaxis, fever and soreness, and pruritis/GI signs/facial swelling and hives?

Answer 22

Anaphylaxis - emergent, typically epinephrine (mayne antihistamines, corticosteroids and IV fluids)
Fever and soreness - NSAIDs
Pruritis, GI signs, facial swelling and hives - diphenhydramine

Question 23

What is vaccine approval?

Answer 23

a vaccine must be liscensed by CFIA (vet biologics branch)
must be made in appropriate facilities, meet safety and potency standards, efficacy (challenge studies 80:80 - *0% protection in vaccinates: 80% dz in non-vaccinates), may only need to show an Ab response, has not always been forced

Question 24

What is the problem in vaccinating very young animals?

Answer 24

Passive protection from colostrum can inactive vx

Question 25

How can we avoid passive protection from colostrum inactivating vaccines in neonates?

Answer 25

eiher vx young animals repeatedly to catch them when they are susceptible or wait until they are old enough so that all antibody from colostrum has disappeared

Question 26

Who is at greatest risk of a vaccine reaction

Answer 26

Sm dogs
animals receiving several vaccines at same time
neutered dogs