Source: CORNELL UNIVERSITY submitted to
PREVENTING LYME DISEASE IN HORSES
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1001073
Grant No.
(N/A)
Project No.
NYC-478401
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2013
Project End Date
Sep 30, 2015
Grant Year
(N/A)
Project Director
Wagner, BE, .
Recipient Organization
CORNELL UNIVERSITY
(N/A)
ITHACA,NY 14853
Performing Department
Vet Population Medicine & Diagnostic Science
Non Technical Summary
What is the current issue or problem that the research addresses and why does it need to be researched? Lyme disease is the most commonly reported vector-borne disease in the US. Lyme disease is caused by the spirochete Borrelia burgdorferi. It is a zoonotic disease affecting humans, dogs, and horses. Bacteria are transmitted to hosts by infected Ixodes ticks. B. burgdorferi causes persistent infection that is believed to last life-long in untreated animals or people. Clinical signs of Lyme disease appear usually several months or even years after infection with B. burgdorferi. Antibiotic treatment of Lyme disease is often successful early after infection but becomes less effective as the infection persists. We used the new Lyme Multiplex Assay available at the Animal Health Diagnostic Center (AHDC) at Cornell University (http://ahdc.vet.cornell.edu/sects/Serol/) to determine the incidence of new infection in horses in 2011 in NY State. Results suggested that B. burgdorferi infected ticks are spreading from their original endemic focus in the northeastern state to a broader area. We also observed an increased public interest in Lyme disease during the past 1.5 years. The AHDC receives about 6000 phone calls from veterinarians on Lyme disease per year and had several requests to provide information about Lyme to newspapers, lay journals and scientific media. Equine veterinarians and clients frequently raised questions about better prevention against infection with B. burgdorferi. Lyme vaccines for horses are not available. Equine veterinarians in Lyme endemic areas often use Lyme vaccines approved for dogs. It is unknown how well these vaccines work in horses and if they induce protective antibodies. What basic methods and approaches will be used to collect and produce data/results and subsequently inform target audiences? We will determine antibody induction by Lyme vaccines in horses. Serum antibodies (vaccination markers) to B. burgdorferi will be evaluated by a new serological assay, the Lyme Multiplex Assay available at the Animal Health Diagnostic Center at Cornell University. We will also test whether commercial Lyme vaccines protect horses from infection with B. burgdorferi. Serum antibodies (infection markers) will be evaluated in horses that are naturally infected after vaccination. Through the methods mentioned above, what ultimate goals does the project hope to achieve? Most importantly, this project will improve equine health and well-being. The outcomes will provide veterinarians, horse breeders, owners and stakeholders in Lyme endemic areas with scientific information about the best available vaccination strategy for horses. In areas where Lyme disease is newly emerging, the work can outline options for disease prevention.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
3113810109050%
3113810110050%
Knowledge Area
311 - Animal Diseases;

Subject Of Investigation
3810 - Horses, ponies, and mules;

Field Of Science
1090 - Immunology; 1100 - Bacteriology;
Goals / Objectives
Objective 1: to determine antibody induction by Lyme vaccines in horses. Serum antibodies (vaccination markers) to B. burgdorferi will be evaluated by the Lyme Multiplex Assay at the AHDC. Objective 2: to test whether commercial Lyme vaccines protect horses from infection with B. burgdorferi. Serum antibodies (infection markers) will be evaluated in horses that are naturally infected after vaccination.
Project Methods
Objective 1: To determine antibody induction by Lyme vaccines in horses, we will vaccinate 3 groups of horses (n=7 per group) with the 3 commercial Lyme vaccines for dogs (1 vaccine per group). Non-vaccinated horses (n=7) will serve as controls. Vaccines and boosters will be given based on the vaccine supplier's recommendation (see below for additional comments). Serum samples will be obtained before (day-7, day -1) and after vaccination (days 5, 8, 14, 21, 28, and then monthly until 1 year post vaccination). Serum samples will be measured using the Lyme Multiplex assay. Objective 2: To test whether commercial Lyme vaccines protect horses from infection with B. burgdorferi, horses will be naturally infected with B. burgdorferi around 5-6 months after vaccination was started. If the vaccine does not prevent infection, we expect OspC antibodies to appear/increase 2-3 weeks and antibodies to OspF 4-6 weeks post infection (p.i.). In addition to the samples above, samples for antibody testing will be taken bi-weekly for the last 7 months of the project to determine if infection occurred. This will be done by detection of antibodies (infection markers) using Lyme Multiplex testing. Infection can be determined based on antibody values alone. The lack of development of clinical disease is not required to determine protection from infection. However, horses will be evaluated for clinical signs at each sampling time point.

Progress 10/01/13 to 09/30/15

Outputs
Target Audience:This project will improve equine health and well-being by providing veterinarians, horse breeders, owners and stakeholders in Lyme endemic areas with scientific information about the best available vaccination strategy for horses. Approved Lyme vaccines for horses are not available. Due to the lack of an equine vaccine, veterinarians often use Lyme vaccines for dogs to vaccinate horses. The safety and efficiency of these dog vaccines in horses was unknown at the beginning of this project. In the past two years, we have performed two vaccination studies in horses using three available canine Lyme vaccines. The resulting data will help veterinarians to make informed decisions on the use of these vaccines in horses and to advice horse owners, breeders and stakeholders with realistic expectations about the protective effects and how to best use these vaccines in horses. Changes/Problems:Because of the results of the first vaccination study, especially the rapid decline of antibodies to vaccination, a second vaccination dose study was performed during this project to extend the data and results from the project beyond the original objectives. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?The results of this study are communicated to veterinarians through the Veterinary Support Service at the Animal Health Diagnostic Center at Cornell University. Two manuscripts are in preparation. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Both objectives were accomplished. Two vaccination studies were performed. To evaluate the effect of vaccination on the immune response of horses the ability of the vaccines to induce antibodies to Borrelia burgdorferi, the pathogen causing Lyme disease, was analyzed. Antibodies were measured in serum before and after vaccination using the Equine Lyme Multiplex assay. This A2LA accredited diagnostic assay is available through the Animal Health Diagnostic Center at Cornell University since 2011 and is frequently used by veterinarians. The assay measures antibodies against three outer surface proteins (Osp) of B. burgdorferi: OspA, OspC and OspF. Antibodies against OspA have been correlated previously with protection from infection in laboratory rodents, dogs and horses. Antibodies against OspC and OspF are indicators of natural infection in non-vaccinated horses. The first vaccination study was performed in horses with three available Lyme vaccines that are approved for Lyme disease prevention in dogs. The ability of the three vaccines to induce antibodies to B. burgdorferi was compared. The results indicated that all three vaccines induce 'protective' OspA antibodies. However, antibody quantities were overall low and the antibody response was short-termed and transient. There was no significant difference in the three vaccines in inducing OspA antibodies. Whole bacterin vaccine also induced OspC and/or OspF antibodies. An additional vaccine boost was given after OspA antibodies declined. It induced another transient OspA antibody response. The second vaccination study compared if an increase of the vaccination dose would increase OspA antibody responses in horses. The vaccine doses of 1 ml (canine dose) and 2 ml were compared using one of the three vaccines. The results indicated that there was a small increase in median OspA antibody values when the higher vaccine dose was used. However, this increase was not significant. Overall, the results showed canine Lyme vaccine induced antibodies in horses are low and short lasting. Additional vaccination can increase the response to provide extended protection from infection with B. burgdorferi. Increasing the vaccination dose does not result in significantly higher antibody responses. Whole bacterin vaccines interfere with the diagnostic ability to detect B. burgdorferi infection in horses. Based on this project, the OspA antibody responses (correlates of protection) are best induced in horses when vaccination is performed in close proximity to the region's Lyme exposure peaks.

Publications


    Progress 10/01/13 to 09/30/14

    Outputs
    Target Audience: Most importantly, this project will improve equine health and well-being. The outcomes will provide veterinarians, horse breeders, owners and stakeholders in Lyme endemic areas with scientific information about the best available vaccination strategy for horses. During the first year of the project, vaccination experiments were performed. After analysis, the resulting data will be published to reach the target audience. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? The sampling and antibody measurements will be completed. All data will be analyzed and a manuscript will be written during the next reporting period.

    Impacts
    What was accomplished under these goals? Objective 1 has been performed. Sample collection for objective 1 is complete and antibody measurements are almost finished. Objective 2 is ongoing. Additional samples are still collected and antibody measurements will be performed afterwards.

    Publications