Duration of immunity induced by companion animal vaccines

Concerns about possible adverse effects from annual vaccination have prompted the reanalysis of vaccine protocols for cats and dogs. In the last decade, several veterinary advisory groups have published protocols that recommend extended revaccination intervals for certain 'core' vaccines. In addition, practicing veterinarians have been asked to consider vaccination as an individualized medical procedure, based on an analysis of risks and benefits for each vaccine in an individual animal. The calls for extended revaccination intervals prompted considerable debate in USA and internationally. Areas of concern include the amount of evidence to support prolonged immunity from various vaccines, the risk of poor responses in individual animals and the possible effects on population immunity. This review examines how the duration of immunity (DOI) to a vaccine is established in animals and humans. It reviews factors that can affect the DOI in an individual animal, including the types of immune defenses stimulated by the pathogen, and the vaccine, host factors such as age and the level of exposure to the pathogen. In addition, it examines DOI studies that were published for canine and feline core vaccines.     

Animal bite epidemiology and surveillance for rabies postexposure prophylaxis

OBJECTIVES: To understand the epidemiology of animal bites and exposure, evaluate the animal exposure reporting system for surveillance of rabies postexposure prophylaxis (PEP), and identify opportunities to reduce PEP. DESIGN: Period prevalence survey. STUDY POPULATION: Pennsylvania residents in 1995. PROCEDURE: Data from animal bite reports from Pennsylvania county health offices were summarized for 1995. Animal bite incidences for the state, counties, various age groups, and various population densities were calculated. Animal species, treatment, location of wounds, and PEP recommendations were evaluated for exposures. RESULTS: More than 16,000 animal-related potential rabies exposures were reported from 65 of 67 counties in Pennsylvania. The highest incidence was in children less than 5 years old (324/100,000). Of the 75% of victims requiring wound treatment, 50% received antimicrobials, 29% received a tetanus toxoid, and 19% had wounds sutured, were admitted to hospitals, or were referred for plastic surgery. Although 75% of exposures were to dogs, victims exposed to cats were 6 times as likely to receive PEP (relative risk, 6.1; 95% confidence interval, 5.1 to 7.4). Thirty percent of 556 PEP were given for exposures to dogs, 44% for cats, 7% for raccoons, 4% for bats, 2.5% for squirrels, 2.1% for groundhogs, 2% for foxes, and 8% for exposures to other species. Fifty-nine percent of owned dogs were up-to-date on rabies vaccinations compared with 41% of owned cats. CONCLUSION: Interventions, such as dog bite prevention education, vaccination of pets against rabies, appropriate use of PEP, and reduction of feral cat populations, should be instituted, enhanced, or better enforced in communities.     

Exposure circumstances and outcomes of 48 households with 57 cats exposed to toxic lily species

Ingestion of Lilium or Hemerocallis spp. by cats can result in renal failure. The objectives of this study were to determine the foreknowledge of lily toxicity of owners of cats that were exposed to lilies and to obtain historical, clinical and outcome information on the exposures. A survey was done of cat owners reporting indoor exposures to lilies to the Animal Poison Control Center (APCC) during April 2009. Forty eight individuals, (57 cats) were included. Sixty nine percent of cat owners said they could recognize a lily and 27% knew that lilies were toxic prior to their cats' exposures. Most lilies were obtained from grocery or other stores, and were purchased by the owners or as gifts to the cat owners. Owners who were unaware of lily toxicity frequently left the flowers where the cats had access to them, whereas in households where the toxicity was known the cats actively sought out the flowers. Of the cats in this study 93% received prompt veterinary care, and 87% either developed no signs or had brief signs that resolved. Five percent had evidence of renal insufficiency at final follow-up and another 5 percent of cats were euthanized due to renal failure.     

Vaccine-associated adverse events.

Although vaccination plays a vital role in maintaining animal health, there are risks associated with this medical procedure. Veterinarians are beginning to reexamine dogmatic vaccine protocols and consider both risks and benefits of vaccination, with special emphasis on adverse event information generated by practitioner experience. The current status of postmarketing surveillance for commercially available veterinary vaccines is presented, along with a discussion of the strengths and limitations of surveillance programs. An overview of adverse events commonly reported by veterinarians is included, along with practical information on how veterinarians can share their observations and learn about adverse events reported by their colleagues.     

Effectiveness of vaccines and vaccination programs for the control of foot-and-mouth disease in Uganda, 2001–2010

Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals. In Uganda, FMD outbreaks are mainly controlled by ring vaccination and restriction of animal movements. Vaccination stimulates immunity and prevents animals from developing clinical signs which include lameness, inappetence, and decreased production. Ring vaccination and restriction of animal movements have, however, not successfully controlled FMD in Uganda and outbreaks reoccur annually. The objective of this study was to review the use of FMD virus (FMDV) vaccines and assess the effectiveness of vaccination programs for controlling FMD in Uganda (2001–2010), using retrospective data. FMD vaccine distribution patterns in Uganda (2001–2010) matched occurrence of outbreaks with districts reporting the highest number of outbreaks also receiving the largest quantity of vaccines. This was possibly due to “fire brigade” response of vaccinating animals after outbreaks have been reported. On average, only 10.3 % of cattle within districts that reported outbreaks during the study period were vaccinated. The average minimum time between onset of outbreaks and vaccination was 7.5 weeks, while the annual cost of FMDV vaccines used ranged from US $58,000 to 1,088,820. Between 2001 and 2010, serotyping of FMD virus was done in only 9/121 FMD outbreaks, and there is no evidence that vaccine matching or vaccine potency tests have been done in Uganda. The probability of FMDV vaccine and outbreak mismatch, the delayed response to outbreaks through vaccination, and the high costs associated with importation of FMDV vaccines could be reduced if virus serotyping and subtyping as well as vaccine matching were regularly done, and the results were considered for vaccine manufacture.     

Immunogenic and protective antigens of Brucella as vaccine candidates

Brucella is an intracellular pathogen that causes abortion in domestic animals and undulant fever in humans. Due to the lack of a human vaccine against brucellosis, animal vaccines play an important role in the management of animal and human brucellosis for decades. Strain 19, RB51 and Rev1 are the approved Brucella spp. vaccine strains that are most commonly used to protect livestock against infection and abortion. However, due to some disadvantages of these vaccines, numerous studies have been conducted for the development of effective vaccines that could also be used in other susceptible animals. In this review, we compare different aspects of immunogenic antigens that have been a candidate for the brucellosis vaccine.     

Invoices and farmer interviews for vaccine-exposure measurement in turkey-broiler production

Exposure measurement in pharmaco-epidemiological studies can be based on various sources that do not always concur. However, reliability is an important criterion when selecting the method used to assess exposure and interpreting the results obtained. An analysis based on invoices might be more informative and more accurate to assess vaccines exposure (yes/no) in turkey broiler production than a questionnaire administered to farmers, which is nevertheless more feasible and less time-consuming. We compared the two methods to assess vaccination exposure in 239 turkey broiler flocks reared in 129 farms in 2000–2001. The agreement (crude agreement and kappa) was calculated, and association between discrepancy and farm and flock characteristics was investigated.

Marek's-disease vaccine, Newcastle-disease vaccine, turkey haemorrhagic-enteritis vaccine and turkey-rhinotracheitis vaccine exposures were reported on the questionnaire for 2.1, 27.6, 93.0, and 98.3% of flocks, respectively, and for 2.1, 29.3, 89.4, and 86.6%, of invoices for the flocks studied, respectively. A discrepancy was observed in 24.9% of flocks. A discrepancy was observed more frequently in specialised farms without any other animal production (OR = 3.6; CI = 1.5, 8.9) and when the farmer did not know whether vaccination had been performed in the hatchery (OR = 7.1; CI = 2.6, 19.7).     

Comparative vaccine-specific and other injectable-specific risks of injection-site sarcomas in cats

Objective-To compare associations between vaccine types and other injectable drugs with development of injection-site sarcomas in cats. Design-Case-control study. Animals-181 cats with soft tissue sarcomas (cases), 96 cats with tumors at non-vaccine regions (control group I), and 159 cats with basal cell tumors (control group II). Procedures-Subjects were prospectively obtained from a large pathology database. Demographic, sarcoma location, basal cell tumor, and vaccine and other injectable history data were documented by use of a questionnaire and used to define case, control, and exposure status. Three control groups were included: cats with sarcomas at non-vaccine sites, cats with basal cell tumors, and a combined group of cats with sarcomas at non-vaccine sites and cats with basal cell tumors. χ(2) tests, marginal homogeneity tests, and exact logistic regression were performed. Results-In the broad interscapular region, the frequency of administration of long-acting corticosteroid injections (dexamethasone, methylprednisolone, and triamcinolone) was significantly higher in cases than in controls. In the broad rear limb region, case cats were significantly less likely to have received recombinant vaccines than inactivated vaccines; ORs from logistic regression analyses equaled 0.1, with 95% confidence intervals ranging from 0 to 0.4 and 0 to 0.7, depending on control group and time period of exposure used. Conclusions and Clinical Relevance-This case-control study measuring temporal and spatial exposures efficiently detected associations between administrations of various types of vaccines (recombinant vs inactivated rabies) and other injectable products (ie, long-acting corticosteroids) with sarcoma development without the need to directly measure incidence. These findings nevertheless also indicated that no vaccines were risk free. The study is informative in allowing practitioners to weigh the relative merits and risks of commonly used pharmaceutical products.     

Efficacy of a killed gpX deleted pseudorabies virus vaccine.

Ten inactivated vaccines containing one of four adjuvants and varying concentrations of pseudorabies virus (PRV) antigens were compared in order to select a vaccine suitable for commercial production. A genetically engineered strain of PRV lacking the gene coding for glycoprotein X (gpX) was used in these vaccines. Vaccinated pigs were challenged intranasally with virulent PRV to determine the efficacy of vaccines. Vaccination of pigs with one dose of experimental vaccines adjuvanted with 50% Montanide ISA 50 or 20% Syntrogen induced a protective immunity at least equal to that induced by two commercially available killed PRV vaccines also evaluated. An experimental vaccine containing 20% Syntrogen was selected and further evaluated according to United States Department of Agriculture licensing requirements. None of the pigs vaccinated with this vaccine produced gpX antibodies detectable by the HerdChek: Anti-PRV-gpX assay. Therefore, this assay could differentiate PRV vaccine induced antibodies from antibodies induced by natural exposure when used in conjunction with this killed gpX deleted PRV vaccine.     

新型动物疫苗佐剂的研究进展

疫苗佐剂是使疫苗免疫原性充分发挥的工具,目前动物疫苗佐剂主要以铝盐佐剂和油乳佐剂为主。近年来基因重组疫苗和亚单位疫苗发展迅猛,而这些新型疫苗与传统疫苗相比免疫原性较弱,这就对佐剂提出了更高的要求。当前针对佐剂的研究层出不穷,部分佐剂如MF59、AS01、AS03等已经在人用疫苗中成功应用,但应用于动物疫苗还有技术难题需要攻破。蜂胶佐剂目前在动物疫苗中应用较广,且已经占有了一定的市场份额。为充分比较现有新型疫苗佐剂的优缺点,为后续疫苗佐剂的研究提供参考,就目前广泛研究的新型动物疫苗佐剂进行综述。     

5-Fluorouracil Toxicosis in the Dog

Twenty-six cases of accidental 5-fluorouracil (5-FU) ingestions by dogs were reviewed from phone calls to the Illinois Animal Poison Information Center. Cases were collected from January 1, 1987 to December 31, 1988. Of the 26 calls involving 5-FU exposures, 12 were classified as "toxicosis," 13 as "suspected toxicosis," and one as "exposure." Dogs were the only species involved in 5-FU cases received during this time. Accurate estimates of the amount of 5-FU ingested by dogs could be made in 17 cases. Ingestion of more than 20 mg/kg of 5-FU was associated with the development of toxicosis. None of the 12 dogs that ingested oral doses in excess of 43 mg/kg (estimated) survived. Clinical signs associated with 5-FU poisoning in the dog were death, seizures, vomiting (with and without blood), tremors, diarrhea (with and without blood), ataxia, and depression. Clinical signs generally developed within 45 to 60 minutes after exposure, and deaths occurred 6 to 16 hours after ingestion.     

布鲁氏菌疫苗的研究现状

Brucellosis caused by Brucella is a zoonotic infectious disease, and not only the serious influence to the healthy development of animal husbandry, but also to human health and public health security that exist a lot of threats.To the current prevention and control measures for animal vaccination, domestic and foreign existing multiple weak vaccines, each vaccine has its advantages and disadvantages, there is no vaccine for human currently, the laboratorys have used genetic engineering and other technical means to actively develop new vaccines, such as recombinant attenuated vaccines and marker vaccines, DNA vaccines and so on, this paper introduces the research status of new vaccines.     

犊牛腹泻大肠杆菌疫苗的研制与应用

根据南京地区犊牛大肠杆菌腹泻流行病学调查结果,用分离鉴定的犊牛腹泻菌株O78、O26、O15大肠杆菌作菌种,制备油乳灭活疫苗,接种初生犊牛预防犊牛大肠杆菌腹泻。结果表明制备的大肠杆菌油乳灭活疫苗接种初生犊牛能产生良好的免疫保护。     

Veterinary Products Committee working group report on feline and canine vaccination

* The working group was set up by the Veterinary Products Committee in response to current concern in both the public domain and in the scientific community about possible health risks related to the routine vaccination of cats and dogs. The working group concluded that vaccination plays a very valuable role in the prevention and control of the major infectious diseases in cats and dogs. Although adverse reactions to vaccination, including lack of efficacy, occasionally occur, the working group concluded that the overall risk/benefit analysis strongly supports their continued use. * Although for some diseases there is evidence of a longer duration of immunity following vaccination than the one year which is typically recommended on the product literature, there is currently insufficient information to propose revaccination intervals other than those proposed by the manufacturer and approved by the regulatory process. * Notwithstanding this, in view of the occasional occurrence of adverse reactions, the working group recommends that the product literature indicates that the regime for booster vaccinations is based on a minimum duration of immunity rather than a maximum. The working group further recommends that the product literature should state that a risk/benefit assessment should be made for each individual animal by the veterinary surgeon in consultation with the owner with respect to the necessity for each vaccine and the frequency of its use. * The evidence suggests that cats appear to be susceptible to the occasional development of sarcomas at sites of injection and there is some further evidence to suggest that, although other products may be involved, this may be more associated with the use of vaccines containing aluminium-based adjuvants. The working group therefore recommends that a generic warning to this effect should appear on the product literature for all feline vaccines administered by injection. The working group also highlighted the need for professional and educational bodies in the UK to bring to the attention of veterinary practitioners appropriate methods for prevention, diagnosis and treatment of this serious condition. * The working group considered in depth the monitoring of adverse reactions, including the advantages and disadvantages of surveillance schemes. A range of options for carrying out further epidemiological (analytical) studies was also considered. However, the working group emphasised that surveillance schemes, and the UK Veterinary Medicines Directorate (VMD) Suspected Adverse Reaction (SAR) Surveillance Scheme in particular, provided a very valuable resource. The large database within the VMD scheme (collected since 1985) was analysed as part of this report. Figures were derived in terms of incidence (reporting rate) of certain clinical signs per 10,000 doses, and risk factors as identified by statistical analysis. However, due to a number of constraints, the analysis was not fully comprehensive and the interaction of possible risk factors was not determined. * Product-related control charts were developed in order to detect changes in incidence rates of adverse reactions (per 10,000 doses sold) both within and between different vaccines. Such charts provide a powerful way to detect changing trends in incidence and, when used in conjunction with product characteristics, they may identify possible causes. In general, the data showed that the incidence of adverse reactions to cat and dog vaccines per 10,000 doses of product sold was relatively low. Although under-reporting is a feature of such surveillance schemes, it does appear that, overall, vaccination of cats and dogs should be considered safe and effective. * Finally, the working group was conscious, while preparing this report, of the extensive media coverage that has been given to the issue of the safety of human vaccines, in particular the mumps, measles and rubella (MMR) vaccine. The working group emphasises that the conclusions and recommendations included in this report relate only to the vaccines used in cats and dogs. The issues identified are specific to the diseases and species examined and no attempt should be made to draw analogous conclusions in relation to vaccines administered to humans.     

Animal poisoning in Italy: 10 years of epidemiological data from the Poison Control Centre of Milan

From 2000 to 2010, the Poison Control Centre of Milan (CAV), in collaboration with the University of Milan, Faculty of Veterinary Medicine, Department of Veterinary Sciences and Technologies for Food Safety, Toxicology Section, collected epidemiological information related to animal poisoning and classified it in an organised and computerised data bank. Data recorded were predominantly related to small animals and to some extent to horses, ruminants and other food-production animals. Few calls were registered involving exotics and no information was recorded on wildlife. The dog was reported to be the most common species involved in animal poisoning, and pesticides constituted the primary group of toxicants. In the case of pets, 'drugs' including veterinary parasiticide and drugs for human use constituted the second class of toxicants responsible for poisoning followed by household products, plants, zootoxins and metals. With regard to horses and farm animals, the second group consisted of phytotoxins, even if only episodically. In Italy, published data on this subject are scarce but this information is crucial for better management of the poisoning of domestic animals in an effort to reduce mortality.     

Use of a public telephone hotline to detect urban plague cases

Current methods for vector‐borne disease surveillance are limited by time and cost. To avoid human infections from emerging zoonotic diseases, it is important that the United States develop cost‐effective surveillance systems for these diseases. This study examines the methodology used in the surveillance of a plague epizootic involving tree squirrels (Sciurus niger) in Denver Colorado, during the summer of 2007. A call‐in centre for the public to report dead squirrels was used to direct animal carcass sampling. Staff used these reports to collect squirrel carcasses for the analysis of Yersinia pestis infection. This sampling protocol was analysed at the census tract level using Poisson regression to determine the relationship between higher call volumes in a census tract and the risk of a carcass in that tract testing positive for plague. Over‐sampling owing to call volume‐directed collection was accounted for by including the number of animals collected as the denominator in the model. The risk of finding an additional plague‐positive animal increased as the call volume per census tract increased. The risk in the census tracts with >3 calls a month was significantly higher than that with three or less calls in a month. For tracts with 4–5 calls, the relative risk (RR) of an additional plague‐positive carcass was 10.08 (95% CI 5.46–18.61); for tracts with 6–8 calls, the RR = 5.20 (2.93–9.20); for tracts with 9–11 calls, the RR = 12.80 (5.85–28.03) and tracts with >11 calls had RR = 35.41 (18.60–67.40). Overall, the call‐in centre directed sampling increased the probability of locating plague‐infected carcasses in the known Denver epizootic. Further studies are needed to determine the effectiveness of this methodology at monitoring large‐scale zoonotic disease occurrence in the absence of a recognized epizootic.     

Exposure to rabies - an occupational hazard for veterinarians

Interviews to solicit information about animal bites and rabies vaccinations were completed on 1165 of 1175 non-military veterinarians in Illinois in 1968. Two hundred and sixty-one veterinarians reported 380 exposure incidents that precipitated the administration of rabies vaccine; 72 veterinarians had received two or more series of vaccine. Vaccine was administered after exposure from: examination of a patient (n = 230), bite (n = 79), necropsy (n = 17), other causes (n = 13) and unstated (n = 41). Eighty-six percent of the exposures were to dogs or cattle. In 231 veterinarians receiving postexposure vaccinations, where year of first vaccination and year of graduation from veterinary school were known, 97 (42%) were exposed in the six years spanning one year before graduation and four years after graduation. There were 296 veterinarians, including 12 receiving postexposure vaccination, who had received their first series of vaccine as preexposure prophylaxis. Twenty-one percent of all vaccinees (pre- and postexposure) reported reactions to the rabies vaccine. Seventy-two veterinarians reported they had been treated for an animal bite in the previous year.     

Survey of veterinary conference attendees for evidence of zoonotic infection by feline retroviruses

OBJECTIVE: To examine exposure risks, possibility of zoonosis, and potential disease associations for feline retroviruses among a group of occupationally exposed individuals. DESIGN: Unlinked voluntary cross-sectional epidemiologic survey. SAMPLE POPULATION: 204 veterinarians, laboratory scientists, and other occupationally exposed individuals who attended a veterinary conference on feline geriatric medicine. PROCEDURE: Blood was collected from participants who also completed a 13-question survey requesting demographic, occupational, exposure, and health information. Blood specimens were fractionated into plasma and mononuclear cell components. Plasma was tested for antibodies against feline immunodeficiency virus (FIV) and feline foamy virus (FeFV), as well as p27 antigen of FeLV. Mononuclear cell lysates were tested for FeLV provirus. RESULTS: Subjects reported extensive duration of work with cats (mean, 17.3 years) and multiple high-risk exposures (eg, cat bites, scratches, and injuries with sharp instruments) per year. However, neither serologic nor molecular evidence of zoonosis with any of the 3 feline retroviruses was detected. CONCLUSIONS AND CLINICAL RELEVANCE: Veterinarians encounter occupational exposures to animal material that place them at high risk for zoonoses. For feline retroviruses, the risk of zoonosis among healthy adult humans appears to be extremely small. However, potential for retroviral zoonosis, especially for viruses such as FeLV and FeFV that can replicate in human cells, cannot be eliminated, and universal precautions to reduce potential exposures should be used when handling sick cats.     

Use of monoclonal antibodies to confirm vaccine-induced rabies in ten dogs, two cats, and one fox

A panel of 8 monoclonal antibodies to rabies glycoprotein antigen was used to characterize the modified-live virus vaccines marketed in the United States during the last 10 years. Thirteen of 14 rabies virus isolates from 11 dogs, 2 cats, and 1 fox suspected of developing vaccine-induced rabies were shown to have reactivity patterns that were identical to the vaccine administered. Reactivity patterns for 20 rabies isolates from human beings, wild animals, or domestic animals with no history of recent vaccination with modified-live virus rabies vaccine were different from those obtained for vaccines.