Effect of size and temperature at vaccination on immunization and protection conferred by a live attenuated Francisella noatunensis immersion vaccine in red hybrid tilapia

Dynamics of piscine francisellosis differs amongst tilapia species (Oreochromis spp.) in a controlled challenge with Francisella noatunensis subsp. orientalis

“…Fish were challenged with 10 3 CFU ml −1 Fno for 1 h under static conditions following published protocols (Soto et al . ). Twenty‐one weeks post‐challenge (November 2014), 30 Fno ‐free tilapia fingerlings for each fish species were added to each tank, separated from their resident cohorts by netting.…”

“…In previous research, fish species, environmental temperature and size of fish were found to play a significant role in the outcome of infection by Fno in controlled laboratory studies, as well as in field studies (Soto et al . , ). In general, Mozambique tilapia, Oreochromis mossambicus (Peters) were found to be significantly more susceptible to francisellosis than Koilapia tilapia, also known as Wami tilapia Oreochromis urolepis hornorum (Trewavas) (Soto et al .…”

Review on Immersion Vaccines for Fish: An Update 2019

“…), francisellosis can present as an acute disease with few clinical signs and high mortality rates or as a sub-acute to chronic infection with non-specific clinical signs. The bacterium is highly infective to tilapia fingerlings [10]. Hybrid tilapia (O. niloticus x O. mosssambicus) fry of 5 g and fingerlings of 10 g were maintained in fresh water at either 25 or 30 • C. Fish were bath vaccinated in a formalin-killed suspension of 7 × 10 5 CFU mL −1 bacteria for 3 h. At four weeks post-vaccination, fish were challenged at 25 • C with 4 × 10 3 CFU mL −1 wild type Fno for 1 h. Because francisellosis does not occur naturally in tilapia at 30 • C, it was necessary to reduce water temperatures prior to challenge.…”

“…Many variables for vaccine efficacy are present and should be considered when conducting immersion vaccination trials [2]. These include vaccine (antigen) dose, duration of immersion, particulate/soluble antigen uptake during immersion immunization of fish [3], adjuvant performance [4][5][6][7][8][9], temperature [10], fish size (age) [10,11], osmolarity, prime boost strategy [1], mucosal integrity [12,13], replicative vs. non-replicative vaccines [1] and how the experimental pathogen challenges are carried out (e.g., virulence of the challenge pathogen, high or low pathogen pressure/load).…”

Immune response of flounder (Paralichthys olivaceus) was associated with the concentration of inactivated Edwardsiella tarda and immersion time

“…Previous researches demonstrated that the antigen uptake and immune efficacy would be influenced by many factors, such as temperature, fish age, nutritional status, type of vaccine, physio-chemical characteristics of vaccine solution and immersion formulation (Xu et al, 2011;Soto et al, 2014;Tatner and Horne, 1985). Among these factors, vaccine concentration and immersion time were proved to largely influence the immune efficacy.…”