Field safety study of VANGUARD®crLyme: A vaccine for the prevention of Lyme disease in dogs

Here we report the results of a large-scale pre-license safety study in which two serials of VANGUARD®crLyme, a vaccine for canine Lyme disease, were tested in its target population (dogs) under the conditions of its intended use. Six-hundred and twenty dogs, from three distinct geographic regions of the United States were enrolled in this study with each receiving two doses of vaccine by subcutaneous injection 3 to 4 weeks apart. Approximately one-third of the dogs were of minimum age (≤8 weeks of age) to meet regulatory requirements. Safety was evaluated by observation of local and systemic reactions for at least 10 days after each vaccination. Abnormal health events (AHEs) occurred at low frequencies and no serious AHEs were observed. The results demonstrated that VANGUARD®crLyme is safe for use in healthy dogs 8 weeks of age or older.

VANGUARD®crLyme: A next generation Lyme disease vaccine that prevents B. burgdorferi infection in dogs

Lyme disease, a public health threat of significance to both veterinary and human medicine, is caused by the tick (Ixodes) transmitted spirochete, Borreliella burgdorferi. Here we report on the immunogenicity and efficacy of VANGUARD®crLyme (Zoetis), the most recent canine Lyme disease vaccine to be approved by the United States Department of Agriculture. VANGUARD®crLyme is a subunit vaccine consisting of outer surface protein A (OspA) and a recombinant outer surface protein C (OspC) based-chimeric epitope protein (chimeritope) that consists of at least 14 different linear epitopes derived from diverse OspC proteins. The combination of OspA and the OspC chimeritope (Ch14) in the vaccine formulation allows for the development of humoral immune responses that work synergistically to target spirochetes in both ticks and in mammals. Immunogenicity was assessed in purpose-bred dogs. A two-dose vaccination protocol resulted in high antibody titers to OspA and Ch14 and vaccinal antibody reacted with 25 different recombinant OspC variants. Efficacy was demonstrated using an Ixodes scapularis -purpose bred dog challenge model. Vaccination with VANGUARD®crLyme provided protection against infection and prevented the development of clinical manifestations and histopathological changes associated with Lyme disease.

Restriction-fragment-length polymorphism analysis of small-subunit rRNA genes of Blastocystis hominis isolates from geographically diverse human hosts

Genomic diversity among 14 isolates of Blastocystis hominis from 4 different geographic locations was examined by small-subunit rRNA (ssu rRNA) restriction-fragment-length polymorphisms (RFLP) using 5 different restriction endonucleases. On the basis of the observed RFLP patterns among the isolates, a total of 12 genotypes were identified, with 7 isolates exhibiting mixed RFLP genotypes. There was no correlation between B. hominis geographic origin and RFLP banding pattern or genotype.

Restriction-fragment-length polymorphism analysis of small-subunit rRNA genes of Blastocystis isolates from animal hosts

The anaerobic enteric protozoan organism Blastocystis sp. has been identified from mammalian, avian, reptilian, and arthropod hosts. Eight Blastocystis isolates from five animal host species (cow, goat, sheep, guinea pig, and rhea) were compared by small-subunit ribosomal RNA (ssu rRNA) restriction-fragment-length polymorphism (RFLP) analyses using five restriction endonucleases. The isolates sorted into five genotypes. Multiple genotypes were found in isolates from a single animal host species, and multiple host species shared a single genotype. A molecular method such as RFLP analysis of ssu rRNA genes facilitates the characterization of Blastocystis isolates from various host species.

Measuring crackles

Crackles heard on auscultation can be represented graphically as a time-amplitude plot of the associated waveform. To assess the relative merits of several measures which might be considered for machine implementation in diagnostic instruments, we compared the reproducibility of those based on the initial voltage deflection which begins a crackle with those based on the largest deflection. The latter group showed less interobserver and less intraobserver variability when the same crackles were measured twice by each of two observers. Crackles from a teaching tape, categorized as fine and coarse, were used in this study. The ability of the various measures tested to distinguish between fine and coarse crackles on an individual basis was assessed and found to favor the measures based on the largest deflection. They showed an average of 9.96 percent incorrectly classified crackles, as opposed to 19.53 percent for the two measures based on the initial deflection.