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2018 Vaccines and Vaccination: Updates and insights

By Richard B. Ford, DVM, MS

Diplomate ACVIM and ACVPM (Hon)

North Carolina State University;  Raleigh, North Carolina

The vaccine “environment” in veterinary medicine is particularly dynamic.  In the coming years, new vaccines will certainly be introduced, information regarding the use and selection of existing vaccines will be revised and updated, and new questions regarding vaccination protocols will surface.  For these reasons, the 2017 AAHA Canine Vaccination Guidelines have been published as an Online Educational Resource (or, OER).  This web-based, mobile-ready format represents a completely new approach to distributing Vaccination Guidelines. The “menu-driven” website enables fast access to the most current information on companion animal vaccines.  In addition, the online format enables “real-time” updates as new information and new vaccines become available. 

AAFP Feline Vaccination Guidelines (last published in 2013) are still in effect, although they are in need of review and update.  Feline vaccination recommendations, and new information pertaining to the use and selection of vaccines for cats, will be addressed during the presentation.

A Reminder…Vaccination Guidelines for the Dog and Cat are recommendations only, not requirements. Protocols for individual animals may vary.  The reader is reminded, however, in States/jurisdictions/provinces where rabies immunization laws are in place, veterinarians are expected to know the law and must follow a vaccination protocol that is consistent with applicable statutes.

NOTE:  Published vaccination recommendations for the dog and cat are based, whenever possible, on the results of current scientific studies.  However, scientific studies are not always available to support all recommendations.  In this lecture and in the Guidelines, recommendations are based on credible science, expert opinion, as well as current knowledge of immunology and infectious disease.  In addition, readers may notice variances between recommendations put forward by vaccine manufacturers and published Guidelines.  Any such variances included in TABLES 1 & 2 have been reviewed by all vaccine manufacturers; recommendations outlined are considered to be safe, effective, and consistent with best immunization practices today.

TABLE 1:   INITIAL VACCINATION of PUPPIES/DOGS

 

CORE Vaccines Administration Booster Recommendations

Combination product administered as:

 

MLV or Recombinant
Canine Distemper  Virus

+ MLV Parvovirus

+ MLV Adenovirus-2

 

OPTION:  May also include MLV Canine Parainfluenza Virus.

Beginning as early as 6 weeks of age, administer sequential doses of a combination vaccine at an intervals of 2 to 4 weeks until at least 16 weeks of age. 

 


Example:  8 weeks; and 12 weeks; 16 weeks, AND, a final dose at 18 to 20 weeks of age as indicated where the risk of exposure is high.  (NEW)

Administer a single dose (of a combination product) not later than 1 year following the last dose in the initial series.

 

NOTE:  a minimum interval of 2 weeks between any 2 doses of vaccine is recommended.

 

Administer subsequent boosters every 3 years (or longer).

Rabies Virus (killed)

 

1-Year & 3-Year vaccines are available.

 

See:  www.rabiesaware.org

A single dose of rabies vaccine is usually administered 12 or 16 weeks of age.

 

 

(State/Local/Provincial law applies)

Schedule a second dose to be administered not later than 1 year following administration of the 1st dose, regardless of the dog’s age at the time the initial dose is given.

 

Then…every 3 years thereafter.

 

(State/Local/Provincial law applies)

NON-CORE VACCINES Administration Booster Recommendations

B. bronchiseptica

 

+ canine parainfluenza (CPiV) (intranasal only)

 

(some IN products may also contain CAV-2 antigen)

Single intranasal (IN) dose at 12 or 16 weeks of age. (optional: some authors recommend 2 doses at 12 and 16 weeks of age).

 

IN vaccine may be administered as early as 3 to 4 weeks of age.

Where risk of exposure is sustained, administer a single dose 1 year following the last dose administered then annually thereafter. 

 

IN vaccine with B. bronchiseptica + CPiV is preferred:  rapid onset, 12 month + DOI; induces mucosal immunity (site of infection).

B. bronchiseptica only (monovalent)

 

Three (3)  options are available:

:
> Parenteral (killed-bacterin)   –or- 

> Intranasal (avirulent live)  -or-

> Intraoral (avirulent live).

Parenteral (SQ):  Two doses are required, 2 to 4 weeks apart.

Intranasal (IN):  The manufacturer recommends a single initial dose.

Intraoral:  The manufacturer recommends a single initial dose.
Where risk of exposure is sustained, administer a single dose 1 year following the last dose administered, then annually thereafter.

Leptospira spp.
(killed) 4-serovar

 

NOTE: routine use of a 2-serovar Leptospirosis vaccine is not recommended.

2 initial doses, 2 to 4 weeks, are required regardless of the dog’s age.

 

NOTE:  Small Breed Dogs (< 20 pounds):  consider delaying initial doses until the CORE vaccine series has been completed.
Where risk of exposure is sustained, administer a single dose 1 year following completion of the initial     2-dose series, then every year thereafter.

Borellia burgdorferi                  (Lyme Disease)

 

Available as:

 

-  Recombinant, or

-  Chimeric/Recombinant, or

-  Killed, whole-cell

2 initial doses, 2 to 4 weeks, are required regardless of the dog’s age and regardless of the type of vaccine selected.

 

NOTE:  Small Breed Dogs (<20 pounds):  consider delaying initial doses until the CORE vaccine series has been completed.

Where risk of exposure is sustained, administer a single dose 1 year following completion of the initial     2-dose series, then every year thereafter.

Canine Influenza Virus (H3N8)
(killed)

 

-and-

 

Canine Influenza Virus (H3N2)(killed)

2 initial doses, 2 to 4 weeks apart are required.

Where risk of exposure is sustained, administer a single dose 1 year following completion of the initial     2-dose series, then every year thereafter.

 

NOTE:  Canine coronavirus vaccination is not recommended.

NOTE:  Crotalus atrox (Western Diamondback rattlesnake) vaccine should only be used in dogs with a defined risk for exposure. Follow the manufacturer’s recommendations for dosing.

NOTE:  An attenuated (MLV) Measles Virus (MV) vaccine is available for administration to young dogs (not less than 8 weeks of age nor older than 12 weeks of age) to protect young dogs against canine distemper virus (CDV).  MV vaccine must be administered by the IM route. 

Overdue for vaccination

NOTE:  Studies focused on dogs that are overdue for routine vaccination have not been published.  Vaccine manufacturers, therefore, have stipulated that the “overdue” patient should receive 2 sequential doses of inactivated vaccine (Leptospira, Lyme, CIV, injectable B. bronchiseptica) regardless of the time elapsed since the patient became overdue. 

HOWEVER, the following recommendations represent expert opinion and are intended to provide a practical approach to immunizing dogs when conventional vaccination guidelines have not been followed:

Overdue during the initial vaccine series:  While most practices administer the initial core vaccine series to young dogs at intervals of 3 to 4 weeks, dogs exceeding a 6-week interval between any of the initial doses should receive at least 2 additional doses, 3 to 4 weeks apart.

The same is true during the initial 2-dose series recommended for dogs receiving non-core vaccines.  If the interval between doses exceeds 6 weeks, 2 additional doses, 3 to 4 weeks apart should be administered.

Overdue for CORE vaccine booster:  administer a single dose of a combination core vaccine regardless of the number of years that have lapsed. 

Overdue for RABIES booster:  requirements for re-vaccination of dogs that are overdue for a rabies booster vary from State to State, and may vary within an individual State.  Many States follow recommendations published in the 2016 Rabies Compendium that states:  administer a single dose, after which the dog will be considered immediately “currently vaccinated”  (ie, immunized).  NOTE:  the Rabies Compendium, as published by the Natl Assoc. of State Public Health Veterinarians, Inc., is NOT a legal document.  Veterinarians must be familiar with rabies immunization requirements and laws within the State, local jurisdiction, or Province in which they practice. (see:  www.rabiesaware.org)

Overdue for Leptospirosis, Lyme and/or parenteral Bordetella booster: dogs that are within 2 years of a previous dose may receive a single dose.  Dogs exceeding a 2-year interval should re-start the initial 2-dose series. 

Overdue for intranasal or intraoral Bordetella booster:  administer a single dose regardless of the number of years that have lapsed.

Overdue for Canine Influenza Virus booster:   dogs that are within 2 years of a previous dose may receive a single dose.  Dogs exceeding a 3-year interval should re-start the initial 2-dose series.

TABLE 2:   INITIAL VACCINATION of CATS/KITTENS

 

CORE Vaccines
Administration
Booster Recommendations

MLV Panleukopenia +

MLV Herpesvirus +

MLV Calicivirus

 

NOTE:  2015 WSAVA and the European Advisory Board on Cat Diseases (2015) recommend avoiding use of killed (adjuvant-containing) vaccines when implementing vaccination protocols for cats.

3 doses are recommended between 8 and 16 weeks of age.

 

Example:

8 weeks; and 12 weeks; and 16 weeks of age… an additional dose at 20 weeks of age may be recommended where risk of exposure is high.

Administer a single dose (of a combination product) not later than 1 year following the last dose in the initial series.

 

Administer subsequent boosters every 3 years.

-  Recombinant Rabies  [adjuvanted-free]
Available as 1-Year & 3-Year products.

 


                      -or-

 

-  Killed Rabies  [adjuvanted]
Available as 1-Year & 3-Year products.

 

See:  www.rabiesaware.org

Single dose is usually administered at 12 or 16 weeks or age.

 

 

 

(State/Local/Provincial law applies)

Schedule a second dose to be administered not later than 1 year following administration of the 1st dose, regardless of the cat’s age at the time the initial dose is given.

 

Then…every 3 years thereafter.

 

(State/Local/Provincial law applies)
NON-CORE VACCINES Administration Booster Recommendations

-  Recombinant Feline Leukemia Virus (rFeLV)
[adjuvant-free]

 

-or-

 

-  Killed Feline Leukemia Virus

[adjuvanted]

Recommended for all kittens:  Administer 1 dose as early as 8 weeks of age followed by a 2nd dose 3-4 weeks later.  Booster 1 year later.

 

The Au recommends 2 doses at 12 and 16 weeks of age followed by a booster 1 year after completion of the initial series.

Where risk of exposure exists…administer a single dose annually thereafter. 

 

(some authors recommend revaccination every 2 or 3 years for cats considered to be at “low risk” for exposure).

Chlamydia felis
(formerly:  Chlamydophila felis and Chlamydia psittaci)

 

(both adjuvant-free and adjuvanted products are available)

2 initial doses 3 to 4 weeks apart, if indicated.

Booster annually where exposure risk is sustained. 

 

Indications for use of this vaccine are limited.

Feline Bordetella bronchiseptica

 

Avirulent Live Intranasal ONLY

(non-adjuvanted)

A single intranasal (IN only) dose administered as early as 4 weeks of age, if indicated.

Booster annually where the risk of exposure is present.

 

NOTE:  indications for use of this vaccine are limited.

Virulent Systemic (VS) Calicivirus

 

 

Killed-adjuvanted

 

2 initial doses 2 to 4 weeks apart, if indicated

The manufacturer recommends annual vaccination where exposure risk is sustained.

 

Disease prevalence is considered low, even within high-density housing environments (eg, shelters).

 

Indications for use of this vaccine are limited.

FELINE VACCINATION (notes)

NOTE:  Unless specifically indicated for intranasal administration, all feline vaccines should be administered by the SQ route.

NOTE:  The Feline Infectious Peritonitis (FIP) vaccine has been re-categorized as NON-Core, but is still not recommended by most authors due to limited or no known efficacy.  The World Small Animal Veterinary Association (Vaccine Guidelines Group) does not recommend administration of either the FIP vaccine on grounds of low to no demonstrated efficacy.

NOTE:  The FIV Vaccine has been discontinued in the US and Canadian markets.

NOTE:  Inactivated (killed), adjuvanted vaccines are recommended for administration to:
           

1.  Pregnant queens, and
           

2.  Retrovirus (FeLV or FIV) infected cats (no studies have been published that define the risk of administering MLV         or recombinant vaccines to retrovirus + cats).

Overdue for vaccination

Studies focused on cats that are overdue for routine vaccination have not been published.  The following recommendations represent expert opinion and are intended to provide a practical approach to immunizing cats when conventional vaccination guidelines have not been followed:

Overdue during the initial vaccine series:  While most practices administer the initial core vaccine series to kittens at intervals of 3 to 4 weeks, cats exceeding a 6-week interval between any of the initial doses should receive 2 additional doses, 3 to 4 weeks apart.

The same is true during the initial 2-dose series recommended for cats receiving non-core vaccines.  If the interval between doses exceeds 6 weeks, 2 additional doses, 3 to 4 weeks apart should be administered.

Overdue for CORE vaccine booster:  ASSUMING USE OF A MODIFIED-LIVE VIRUS VACCINE, administer a single dose of a combination core vaccine regardless of the number of years that have lapsed. 

Overdue for RABIES booster:  requirements for re-vaccination of cats that are overdue for a rabies booster vary from State to State, and may vary within an individual State.  Many States follow recommendations published in the 2016.  Rabies Compendium that states:  administer a single dose, after which the cat will be considered immediately immunized.  NOTE:  the Rabies Compendium, as published by the Natl Assoc. of State Public Health Veterinarians, Inc., is NOT a legal document.  Veterinarians must be familiar with rabies immunization requirements and laws within the State, local jurisdiction, or Province in which they practice.  See:  www.rabiesaware.org

Overdue for Feline Leukemia booster: this is complicated…compared to kittens, adult cats are significantly more resistant to developing progressive disease associated with FeLV infection.  For this reason, significant differences of opinion exist with respect to conventional intervals (annual, biennial, triennial recommendations exist).  It would be reasonable to recommend that the initial 2-dose series should be restarted in the event a cat is more than 3 years overdue for vaccination. 

 

2018 VACCINES & VACCINATION:  20 Questions (and…the “Must Know” Answers)

1. Why administer 3 initial doses of D-A2-P, but only 1 dose of Rabies?

3 initial doses of a D-A2-P (distemper-adenovirus-parvovirus) vaccine are recommended to assure at least 1 dose is administered to the young dog at a time when interfering levels of maternal antibody are no longer circulating.  In the absence of maternal antibody (eg, orphan pups), a single dose of D-A2-P is expected to protect.  Because maternal antibody levels can wane at different times, and we don’t ‘measure’ those levels, the point behind 3 doses is to be there when maternal antibody isn’t.

Rabies vaccine administration is different…primarily because State/local statutes dictate the species and the dosing regimen…which usually, but not always, follows recommendations outlined in the Rabies Compendium.  (NOTE:  In CANADA, Ontario is the only province that requires rabies vaccination of dogs/cats)

But, there’s more…in immunology, administration of the first (initial) dose of any killed (inactivated) vaccine merely “primes” the immune response…it does not immunize a patient.  In the case of rabies, 1 initial dose (administered NOT earlier than 12 weeks of age) is considered “protective” for a year…REASON:  if a vaccinated (first-dose only) dog/cat is actually exposed to rabies virus, the exposure serves as the second, or immunizing, “dose”.  It’s a race between the virus (exposure) and the immune response (antibody).  Because rabies virus is slow to invade the nervous system (several weeks to months), the secondary immune response (occurring within 2 weeks) wins, and the patient is protected.

And…another point…after administration of the initial rabies vaccine dose…regardless of the patient’s age…most (but not all) States stipulate that the patient is not “currently vaccinated” until 28 days following the initial dose.  That’s because it does take a few weeks for the “priming” effect to occur. 

 

2. Why the optional D-A2-P dose at 18 to 20 weeks of age?

Recent serological surveys of young dogs from practices throughout the US (U of Wisconsin) have shown that maternal antibody interference can occur in some dogs that are 16 weeks of age, and even older.  In some practice locations, veterinarians are diagnosing canine parvovirus or distemper infections in dogs that have been vaccinated (and usually in a lot of dogs that are NOT vaccinated).  These “high virus pressure” environments typically occur where vaccination compliance in young dogs is poor…and exposure risk is high.  In these practice locations, veterinarians are encouraged to consider administering an additional dose of a combination D-A2-P vaccine at 18 to 20 weeks to further ensure protection in the young dog. 

3. Does a half-dose of vaccine (0.5 mL) immunize a “small” dog?
(The bigger question:  “what’s the justification behind dose-reduction?”)

In a word…arbitrarily reducing the dose of vaccine on the basis of the size/weight of the patient is not recommended…WHY?  …doing so is off-label, doing so may not immunize the patient (regardless of size), and if something does go wrong (eg, the dog gets the disease it was vaccinated against), there’s the liability issue (think rabies). 

But, there’s another issue...a prominent reason behind the decision to reduce the volume of vaccine administered to a ‘small’ dog is generally based on the assumption that smaller dogs are more likely to have a reaction if a full (1.0 mL) is administered.  Despite individual experiences, there are no studies that support the assumption…and, if the reaction is truly ‘allergic’, reducing the dose is not likely to alter the reaction risk in a hypersensitive patient.

Killed (inactivated) vaccines are more often linked to adverse reactions than modified-live or recombinant vaccines.  But this point is still debated in the literature.  On the other hand, it has been shown that giving multiple doses of vaccine to a small breed dog (≤ 10 kg body weight) at the same appointment is associated with a higher risk for adverse reaction. (See the next question)
 

4. Vaccination protocols for small breed dogs?

Current Guidelines do suggest that limiting the number of doses administered to small breed dogs (≤ 10 kg body weight) may reduce the risk of an adverse reaction.  Further, it is recommended that during the initial vaccination series, the core vaccines be given priority and, when appropriate, delay (by 2 or more weeks) administration of the non-core vaccine doses (eg, leptospira and Lyme disease).  This does mean the owner is subjected to additional visits.  Yet, veterinarians who recommend separating the core and non-core administration schedule report high owner compliance, particularly when this is positioned as a safety issue.

 

5. What are the indications for Antibody Testing (vaccine) in practice?

Among the most common reasons (probably THE most common reason) for performing antibody testing (for vaccine-associated antibody) in practice is “owner requested”.  Antibody testing in practice is, at least now, largely client-driven.  The 2017 AAHA Guidelines include a new section that addresses specific indications for testing, and offers a patient management algorithm for each…ie, what to do if the test result is POS vs. NEG.  Consider a few of the indications:

Assess immunity following completion of the initial series.
Assess immunity rather than administer a booster.
Assess immunity when overdue for a booster.
Assess immunity when there is no reliable vaccination history.
Identification of ‘genetic non-responders’ (parvovirus).
Pre-breeding assessment of immunity (controversial).

 

6. Does a “positive” antibody test result for D-A2-P correlate with protection?

Yes…whether using a quantitative test (commercially available antibody titer) or a qualitative test (in-clinic test kit), results indicating the patient is POSITIVE for antibody to distemper virus, parvovirus, and adenovirus do correlate with protection.

7. Does a “positive” rabies antibody titer (RVNA) correlate with protection?

From an immunologic perspective, ongoing studies suggest that a POSITIVE RVNA likely does correlate with protection against rabies. 

From a legal perspective, however, throughout the US and Canada, a POSITIVE RVNA is interpreted as evidence of prior rabies vaccination…and is not a legal index of immunity.  That’s why a POSITIVE RVNA cannot be substituted for rabies vaccination.

8. What’s the point of a rabies antibody titer when exporting a dog/cat?

The importing region/country uses a POSITIVE RVNA as evidence of prior vaccination…not proof of protection.

9. Why does AAFP list feline rabies vaccination as NON-CORE?

Current AAFP Guidelines (2013) were written by an Advisory Board comprised of veterinarians from the US, Canada, Europe, and the UK.  Because the UK is rabies-free, and rabies vaccination is not routinely administered to dogs/cats, rabies vaccination was listed as “non-core”.  It should be noted, however, that the US and Canadian representatives on that Board do, in fact, recommend rabies vaccination of all cats and dogs, whether or not an individual State or Province mandates vaccination.  

10. Why isn’t Leptospira vaccine “core”?

Despite being listed in Guidelines as a non-core vaccine, many practices throughout North America do recommend Leptospira vaccine as core.  And, there is justification for doing so:  leptospirosis is zoonotic, infection in unvaccinated dogs can be lethal, L. grippotyphosa has emerged as the predominant infecting serovar in the US (that why a 4-way vaccine is recommended over the 2-way vaccine), infections tend to occur in clusters or localized outbreaks, but occurrence is not predictable.  Risk factors for exposure and infection have changed…(see the next question)

 

11. Risk Factors for leptospirosis infection?

Risk factors for leptospirosis have conventionally focused on the large-breed dog living in a rural farm/ranch setting that has access to free-standing water.  Today, the risk profile has changed considerably.  Small-breed dogs living in urban settings now have the highest risk for infection.  Infection risk should not necessarily be excluded because the dog lives in an arid region (re:  the 2017 outbreak in Maricopa County [Phoenix] AZ).

12. 3 formulations of Bordetella bronchiseptica vaccine…how do they compare?

Head-to-head studies comparing intranasal, oral, and parenteral B. bronchiseptica vaccine are limited.  Conclusions reached by the AAHA Canine Vaccination Task Force, based on a comprehensive literature review led to the following recommendations.

All 3 types of vaccine containing B. bronchiseptica antigen are effective at reducing clinical signs associated with a controlled challenge.

Intranasal (IN) B. bronchiseptica + CPiV (± CAV2) provides rapid onset (2-3 days), sustained protection (12-14 months) against B. bronchiseptica, and likely CPiV as well, following a single dose.  For these reasons, the AAHA Canine Guidelines preferentially recommends IN vaccination against B. bronchiseptica and CPiV.

Oral B. bronchiseptica vaccine likely provides rapid onset, sustained protection as well.  The duration of immunity of the oral vaccines is not known.  NOTE: none of the oral vaccines contain CPiV antigen, an important pathogen in the infectious respiratory disease complex. 

The parenteral B. bronchiseptica vaccine is an inactivated product that requires 2 sequential doses to induce an immune response.  The duration of immunity induced by the parenteral vaccine is unknown.  The parenteral vaccine provides no mucosal immunity (secretory IgA).

 

13. Should Bordetella bronchiseptica vaccine be CORE?

It is reasonable to vaccinate all dogs with a product containing B. bronchiseptica…although Guidelines currently list B. bronchiseptica-containing vaccine as non-core, the option to recommend it as core is left to the discretion of the individual veterinarian who is best able to assess risk factors in the individual patient. 

14. Canine Influenza Virus….Canine Parainfluenza Virus…How real the risk?

Both strains of CIV (H3N8 & H3N2) as well as CPiV pose a risk to dogs if exposed.  Alone, any of these viruses can cause mild, self-limiting disease lasting 3 to 4 weeks.  Although highly contagious, healthy dogs that become infected may not manifest clinical signs of cough/nasal discharge.  The clinical consequences of infection may be most significant in dogs with underlying chronic respiratory disease (eg, chronic bronchial disease) or in dogs co-infected with another respiratory pathogen (eg, B. bronchiseptica).

Despite the media attention given to CIV throughout North America, exposure risk has been essentially limited to dogs living in the US.  Only recently (2018), a small number of dogs were confirmed to have CIV (H3N2) in southern Ontario. Despite the availability of CIV vaccine in Canada, administration should be limited to dogs that are frequently co-mingled with other dogs and/or travel (especially to participate in dog shows in the US)….which supports the recommendation for B. bronchiseptica as core.

15. Initial vaccination protocol against canine Lyme Disease? 

In Canada, as well as the US, canine Lyme disease continues to spread, largely resulting from the movement of migratory, ground feeding birds transporting infected ticks.  In Canada, canine Lyme disease risk is significant throughout most of southern Ontario and Quebec, including Quebec City, parts of New Brunswick and Nova Scotia. 

Conventional initial vaccination protocol entails 2 sequential doses, 3 to 4 weeks apart, followed by annual boosters for dogs with sustained risk for exposure.  Anecdotal reports, not substantiated by clinical studies, have suggested that for dogs residing in endemic (high risk) areas may benefit from a modified initial vaccination protocol that entails 2 initial doses, 3 to 4 weeks apart, followed by a booster 6 months later and another booster 6 months after that. (The early human Lyme vaccine research did show significantly improved immunogenicity following administration of 3 initial doses vs. just 2).   Annual boosters would be indicated thereafter if the risk is sustained.  Is the modified protocol “better” than the conventional label protocol?  To date, there are no studies documenting one protocol as preferential over another. 

 

16. Lots of Canine Lyme Disease vaccines…what’s the difference?

With 4 different types of canine Lyme vaccine on the market, competition for market share is particularly intense within endemic regions of the US and Canada. 

KILLED, Whole-cell:  The original canine Lyme disease vaccine (Wyeth/Fort Dodge) consisted of a killed (inactivated), whole-cell (bacterial) adjuvanted vaccine.  Immunity is conferred through development of antibody to the outer-surface protein A (OspA). 

A second killed, whole-cell bacterial vaccine licensed as an aid in the prevention of canine Lyme disease utilizing 2 outer-surface proteins (A and C).  The marketing message being that OspA antibody targets B. burgdorferi in the midgut of the tick thereby inhibiting transmission.  OspC, on the other hand, targets B. burgdorferi in the dog.  In the event any organisms were to escape OspA antibody and are effectively transmitted, OspC antibody would target those.  However, the immunogenicity of OspC, independent of OspA, has yet to be demonstrated in clinical studies. 

RECOMBINANT vaccines:  There are 2.  One is non-adjuvanted OspA (only) vaccine…ie, there are no bacterial cells in the vaccine.  OspA antibody produced is absorbed by the tick during feeding, attaches to spirochetes in the midgut of the tick, and prevents transmission.

A second recombinant canine Lyme disease vaccine has recently been licensed that contains OspA plus a chimeric OspC. 

Immunogenicity (quality of protection) and reactogenicity (adverse reaction risk) of these vaccine types will be discussed during the presentation.

 

17. Should Lyme disease vaccine be CORE?

Vaccination (and you know this) is just part of the protection equation for canine Lyme disease.  Compliance with routine, proper administration of an oral or topical tick preventative is very important in protection against infection.  In endemic (reservoir) regions, the vaccine offers an important additional layer of protection.  For that reason, it is not unusual for veterinarians practicing in endemic regions of the US and Canada to offer canine Lyme disease vaccination as core.

 

18. Acute reaction following vaccination…steroids vs. vaccine?

Management of dogs deemed to be at risk for an acute adverse reaction (especially facial angioedema) associated with vaccination typically entails administration of either diphenhydramine (antihistamine) or a corticosteroid, administered either by injection or orally at the time of or just prior to vaccination…some veterinarians administer an antihistamine and a steroid prior to vaccination. 

At issue:  does administration of corticosteroid concurrently with a vaccine interfere with the immune response to the vaccine? 

In a word…NO.  In dogs, cats, and humans, rather large doses of corticosteroids administered over long periods (months) are necessary to alter the humoral immune response to a vaccine.  A single, or even short-term steroid administration, is not sufficient to impact the immune response to a dose of vaccine.

 

19. Should FeLV vaccine be CORE for all cats?

Current AAFP Feline Vaccination Guidelines recommend FeLV as core for ALL kittens…the reason:  the risk of infection is significantly greater in young cats (less than 6 to 8 months of age) compared to adult cats.  The relatively greater level of “protection” that adults have over kittens is likely due to the fact that adult cats have a more “mature” immune response, possibly linked to the production of one or more of the interleukins. 

2 initial doses, 2 to 4 weeks apart are recommended followed by a booster dose within one year.  Adult cats that have little to no interaction with other cats are unlikely to benefit from administration of additional booster doses.  Adult cats that do interact (fight) with other cats, justifiably should receive a booster dose every 1 to 2 years as long as the risk is sustained.
 

20. Feline Vaccination….injection-site sarcoma…current recommendations?

Still a continuing point of debate and discussion is the role of adjuvant (which is present in all inactivated feline vaccines, eg: killed rabies and killed FeLV vaccines) in causing feline injection-site sarcoma (FISS).  Several research studies and expert consensus statements do recommend against administration of adjuvanted vaccines to cats. 

Anecdotal as this may sound, I continue to hear reports from veterinarians throughout the US that indicate the incidence of feline injection-site sarcomas in their practice dropped (significantly or completely) after switching to NON-adjuvanted vaccines, exclusively. 

In the current feline vaccine market, none of the recombinant or modified-live virus (MLV) vaccines contain adjuvant…on the other hand, ALL of the killed (inactivated) vaccines do contain adjuvant.

The point:  Avoid administering killed vaccine to cats. 
 

Updated:  February 2018CV