539
compared to heat-killed products (Kusuda et al. 1978b ; Itami and Kusuda 1980 ).
The potential of LPS as an immunogen was clearly demonstrated by Salati et al.
( 1989b ). These workers injected i.p. crude LPS (0.05–0.5 mg) into ayu. Following
challenge, mortalities among the vaccinates and controls were 0 % and 86.7 %,
respectively. Similarly, O-antigen preparations induced an immune response following injection in a wide range of fi sh species, including ayu, carp, Japanese eel,
Japanese fl ounder, rainbow trout and red sea bream (Nakamura et al. 1990 ).
Incorporating purifi ed 43 kDa OMP of Aer. hydrophila in FCA and a booster 3
weeks later (without FCA) led to a demonstrable immune response and protection
against challenge by V. anguillarum in blue gourami (Trichogaster trichopterus)
(Fang et al. 2000 ). The ompK gene was cloned and sequenced, and recombinant
protein was overexpressed, purifi ed, and purifi ed protein, ompK, administered to
Indian major carp ( Labeo rohita ), which were protected from challenge (Hamod
et al. 2012 ). Development of live attenuated vaccines have been tried, with some
success (Norquist et al. 1989 ; 1994 ). A fi eld trial with an attenuated live V. anguillarum vaccine [VAN1000] involved bathing 10 g rainbow trout in a dose equivalent
to 1 × 10
6 cells/ml for 60 min at 9 °C in brackish water. Following a natural challenge, 68 % of the unvaccinated controls succumbed compared to 14 % of the vaccinates (Norquist et al. 1994 ). Interestingly, these workers considered that the live
vaccine protected against both furunculosis and vibriosis. However, there may be
problems with regulatory authorities regarding licensing for fi sheries use.
To date, most of the vaccine development programmes have concentrated on
bivalent products, containing cells of V. anguillarum a nd V. ordalii (e.g. Nakai et al.
1989 ). At various times, these have been applied to fi sh by injection (of dubious
practicality for masses of fi sh), on food (oral administration), by bathing/immersion, by spraying, and by anal and oral intubation. The evidence has shown that oral
application, perhaps the most convenient method, fares least successfully. Indeed,
comparative vaccine trials have produced a wealth of information. For example,
Baudin-Laurençin and Tangtrongpiros ( 1980 ) reported cumulative percentage mortalities among experimental groups of fi sh, as follows:
unvaccinated controls 33.8 %
oral-vaccinated fi sh 31.7 %
immersion vaccinated group 2.1 %
group vaccinated by injection 1.4 %
Similar fi ndings, although generally more favourable for orally administered
vaccines, were published by Amend and Johnson ( 1981 ) and Horne et al. ( 1982 ).
Thus, Amend and Johnson ( 1981 ) revealed the following mortalities in vaccinated
salmonids:
unvaccinated controls 52 %
oral-vaccinated fi sh 27 %
immersion vaccinated group 4 %
spray vaccinated fi sh 1 %
group vaccinated by injection 0 %
Vibrio anguillarum
compared to heat-killed products (Kusuda et al. 1978b ; Itami and Kusuda 1980 ).
The potential of LPS as an immunogen was clearly demonstrated by Salati et al.
( 1989b ). These workers injected i.p. crude LPS (0.05–0.5 mg) into ayu. Following
challenge, mortalities among the vaccinates and controls were 0 % and 86.7 %,
respectively. Similarly, O-antigen preparations induced an immune response following injection in a wide range of fi sh species, including ayu, carp, Japanese eel,
Japanese fl ounder, rainbow trout and red sea bream (Nakamura et al. 1990 ).
Incorporating purifi ed 43 kDa OMP of Aer. hydrophila in FCA and a booster 3
weeks later (without FCA) led to a demonstrable immune response and protection
against challenge by V. anguillarum in blue gourami (Trichogaster trichopterus)
(Fang et al. 2000 ). The ompK gene was cloned and sequenced, and recombinant
protein was overexpressed, purifi ed, and purifi ed protein, ompK, administered to
Indian major carp ( Labeo rohita ), which were protected from challenge (Hamod
et al. 2012 ). Development of live attenuated vaccines have been tried, with some
success (Norquist et al. 1989 ; 1994 ). A fi eld trial with an attenuated live V. anguillarum vaccine [VAN1000] involved bathing 10 g rainbow trout in a dose equivalent
to 1 × 10
6 cells/ml for 60 min at 9 °C in brackish water. Following a natural challenge, 68 % of the unvaccinated controls succumbed compared to 14 % of the vaccinates (Norquist et al. 1994 ). Interestingly, these workers considered that the live
vaccine protected against both furunculosis and vibriosis. However, there may be
problems with regulatory authorities regarding licensing for fi sheries use.
To date, most of the vaccine development programmes have concentrated on
bivalent products, containing cells of V. anguillarum a nd V. ordalii (e.g. Nakai et al.
1989 ). At various times, these have been applied to fi sh by injection (of dubious
practicality for masses of fi sh), on food (oral administration), by bathing/immersion, by spraying, and by anal and oral intubation. The evidence has shown that oral
application, perhaps the most convenient method, fares least successfully. Indeed,
comparative vaccine trials have produced a wealth of information. For example,
Baudin-Laurençin and Tangtrongpiros ( 1980 ) reported cumulative percentage mortalities among experimental groups of fi sh, as follows:
unvaccinated controls 33.8 %
oral-vaccinated fi sh 31.7 %
immersion vaccinated group 2.1 %
group vaccinated by injection 1.4 %
Similar fi ndings, although generally more favourable for orally administered
vaccines, were published by Amend and Johnson ( 1981 ) and Horne et al. ( 1982 ).
Thus, Amend and Johnson ( 1981 ) revealed the following mortalities in vaccinated
salmonids:
unvaccinated controls 52 %
oral-vaccinated fi sh 27 %
immersion vaccinated group 4 %
spray vaccinated fi sh 1 %
group vaccinated by injection 0 %
Vibrio anguillarum