Time of vaccination influences development of adhesions, growth and spinal deformities in Atlantic salmon Salmo salar

Abstract

In August 1998, 3000 Atlantic salmon Salmo salar L. parr were divided into 7 groups with 2 replicates. Every 6 wk until March of the following year 1 group was vaccinated. One group was held as an unvaccinated control. The fish were transferred to seawater in May 1999, and slaughtered in February 2000. Temperature, fish size and photoperiod at vaccination, and the time between vaccination and sea transfer thus varied among the groups. In all vaccinated groups, growth was reduced for 1 to 2 mo following vaccination. Intra-abdominal lesions developed faster, and stabilised at a higher level in the groups vaccinated early at the highest temperature and the smallest fish size. Growth in seawater was influenced by the time of vaccination. At the end of the experiment, the group vaccinated last (MAR) was the heaviest of the vaccinated groups (4.0 kg), and the group vaccinated first, i.e. in August (AUG) was smallest (3.2 kg). Growth rate in seawater differed only in the summer when specific growth rate was above 1.45 in all groups. There was a correlation between adhesion, condition factor and number of weeks from vaccination to sea transfer. The AUG group had the highest condition factor, with a top level of 1.64 in autumn, and this group also displayed the highest incidence of deformed vertebra. The experiment shows that side effects of vaccination can be significantly reduced when planning the vaccination strategy, by taking environmental factors and fish biology into consideration.

Collagen type XI α1 may be involved in the structural plasticity of the vertebral column in Atlantic salmon (Salmo salar L.)

“…in the anterior and posterior parts (Berg et al, 2006;Witten et al, 2005). This malformation seem to develop late in ontogeny (Berg et al, 2006;Witten et al, 2006;Fjelldal et al, 2007b), and has been associated with factors such as mineral malnutrition , and vaccination (Berg et al, 2006). Compressed vertebrae have been characterized morphologically (Kvellestad et al, 2000;Witten et al, 2005;Fjelldal et al, 2007a;Fjelldal et al, 2007b), however, the molecular pathways underlying the pathogenesis have yet to be identified.…”

“…In a deformed vertebra this angle increases to approximately 90 deg. in the anterior and posterior parts (Berg et al, 2006;Witten et al, 2005). This malformation seem to develop late in ontogeny (Berg et al, 2006;Witten et al, 2006;Fjelldal et al, 2007b), and has been associated with factors such as mineral malnutrition , and vaccination (Berg et al, 2006).…”

“…Low mineral content and mechanical strength of the vertebrae have been associated with the development of vertebral anterior-posterior compression Fjelldal et al, 2007b;Fjelldal et al, 2009), which is the most common deformity in farmed Atlantic salmon and is usually restricted to the tail region of the vertebral column (Witten et al, 2005;Berg et al, 2006;Fjelldal et al, 2008). A compressed vertebra has a normal central part where the angle between the wall of the cone of the vertebra and the anterior-posterior axis is approximately 45 deg.…”

Aeromonas salmonicida Binds Differentially to Mucins Isolated from Skin and Intestinal Regions of Atlantic Salmon in an N -Acetylneuraminic Acid-Dependent Manner

“…Vaccinations are usually successful, but the protection is not absolute, and vaccinations often lead to reduced welfare through injuries and behavioral changes. Pathological changes after intraperitoneal vaccinations include peritonitis (8), soft tissue adhesions (9,10), and deposition of melanin (11) but also skeletal deformities (12,13). Further, the behavior of the fish is affected; intraperitoneal vaccination, using oil-based adjuvants, has been shown to reduce food intake and interest in feed, as well as swimming activity (8).…”

Vaccination-Induced Systemic Autoimmunity in Farmed Atlantic Salmon

“…The vaccines commonly used contain an oil-based adjuvant (4), such as mineral hydrocarbon oil and emulsifier (same as IFA, containing mineral oil Bayol F and emulsifier) or animal/vegetable oil that contains pristane (2,6,10,14-tetramethylpentadecane) (5) or squalene (6). A number of undesirable side effects have been attributed to the vaccination of salmon, including retarded growth, chronic peritonitis with pigmentation and adhesion of internal organs (7)(8)(9), granulomatous uveitis (10), and spinal deformities (11).…”