Investigation of the Systemic Antibody Response and Antigen Detection Following Intranasal Administration of Two Commercial Equine Herpesvirus-1 Vaccines to Adult Horses

EHV-1 vaccines are often administered intranasally during emergency situation such as outbreaks of equine herpesvirus myeloencephalopathy. However, there is currently no data available on the efficacy of such protocols, nor the diagnostic challenge when recently vaccinated horses become clinically infected and nasal secretions are collected to support a diagnosis of EHV-1 infection. Therefore, the objective of this study was to determine if two commercially available EHV-1 vaccines, a killed-adjuvanted (Calvenza) and a modified-live (Rhinomune) EHV-1 vaccine, could induce a measurable systemic antibody response postintranasal administration. A second objective was to determine the detection time of EHV-1 in nasal secretions by qPCR following the intranasal administration of the respective EHV-1 vaccines. Thirty healthy adult horses, with no recent EHV-1 vaccine administration, were randomly assigned to one of three groups: Rhinomune group, Calvenza group, and unvaccinated control group. Total Ig and isotype-specific IgG4/7 against EHV-1 measured pre- and 30-days post-vaccination were not different amongst the three study groups. Vaccine-derived EHV-1 was only detected in the two EHV-1 vaccine groups with 9/10 horses in the Rhinomune group and 8/10 horses in the Calvenza group testing qPCR-positive for EHV-1 for 1 to 3 days. There was no significant difference in number of horses testing qPCR-positive for EHV-1 and absolute quantitation of EHV-1 in nasal secretions by qPCR between the two vaccine groups. The intranasal administration of two commercial EHV-1 vaccines did not elicit a systemic immune response. Further, vaccine derived EHV-1 could be detected in the majority of the intranasally vaccinated horses, potentially impacting diagnostic interpretation of EHV-1 during outbreak situations.

Seroprevalence of SARS-CoV-2 in 1186 Equids Presented to a Veterinary Medical Teaching Hospital in California from 2020 to 2022

While some companion animals have been shown to be susceptible to SARS-CoV-2, their role in the COVID-19 pandemic has remained poorly investigated. Equids are susceptible to SARS-CoV-2 based on the similarity of the human ACE-2 receptor and reports of infection. Clinical disease and prevalence factors associated with SARS-CoV-2 infection in equids have not yet been investigated. The aim of this study was to determine the seroprevalence of SARS-CoV-2 and selected prevalence factors in 1186 equids presented for various conditions to a Veterinary Medical Teaching Hospital over a two-year period. Blood samples were tested for SARS-CoV-2 antibodies using an ELISA targeting the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. Further, selected prevalence factors (season, age, breed, sex, presenting complaint) were retrieved from the medical records. No information was available on whether the horses had come into contact with COVID-19-positive individuals. Among the study animals, 42/1186 (3.5%) horses had detectable SARS-CoV-2 antibodies. Amongst the prevalence factors investigated, only seasonality (spring) was associated with a greater frequency of seropositivity to SARS-CoV-2. Horses with medical and surgical complaints were more likely to test seropositive to SARS-CoV-2 compared to horses presented for routine health care procedures, suggesting more frequent and/or longer interactions with individuals with COVID-19. While horses can become infected with SARS-CoV-2 via the occasional spillover from COVID-19 individuals, clinical disease expression remains subclinical, making horses an unlikely contributor to the spread of SARS-CoV-2.

The 1996 Clinical Research award. Use of a pneumatonometer in burn scar assessment

The evaluation of wound outcome after burn injury is a challenging problem in the performance of clinical trials evaluating potential impact on wound healing and scar formation. The purpose of this study was to determine whether an ocular tonometer could be adapted to provide an objective measurement of scar compliance. A pneumatonometer was used to perform measurements of cutaneous compliance at 8 anatomic areas (14 separate sites) on each of 17 normal volunteers and on 59 burn scars. Comparison of different anatomic sites showed there to be significant differences in the cutaneous compliance of different areas. The aggregate compliance of the burn scars in all sites was less than that of the control sites. These results indicate that the pneumatonometer can discern differences in the compliance of normal skin and differences between normal skin and scar and suggest that it may be a useful tool in the objective assessment of scar formation.

Early assessment of pediatric burn wounds by laser Doppler flowmetry

Evaluation of burn wound depth in pediatric patients is often difficult. A Laser Doppler Flowmeter with a temperature-controlled multichannel probe was used to measure burn wound perfusion as a tool to predict wound outcome. The average perfusion levels for wounds that healed spontaneously in fewer than 21 days was significantly higher than the average perfusion levels for wounds that required excision and grafting or were not healed by day 21 after burn injury. Laser Doppler Flowmetry showed high positive predictive values for "nonhealing" wounds on postburn days 1, 2, and 3. These results suggest that Laser Doppler Flowmetry is a useful tool for burn wound assessment in pediatric patients.