Vaccines against streptococcosis in tilapia have been developed
previously with sceptical protection to control the disease. Evans
et al. [6] had produced a whole cell killed vaccine of S. agalactiae
that confer excellent protection against S. agalactiae. The vaccine is
recommended to be given intraperitoneal (IP) to 30 g Red hybrid
tilapia. Another available vaccine is AquavacGarvetil, which was
produced by Schering-Plough Animal Health Corporation against
Lactococcus and S. iniae via immersion dip administration. The
subproduct for this vaccine was AquavacGarvetil Oral which was
also applied by mixing the vaccine with the feed. However, this
vaccine only works with S. iniae and not for S. agalactiae. The latest
vaccine that was produce against streptococcosis was adjuvanted
whole cell vaccine incorporated in the pellet for oral administration
[7]. This vaccine contained whole cell killed S. agalactiae and provided
satisfactory protection against the infection. Following Firdaus’s
study [7], we developed a similar vaccine using a
recombinant gene of cell wall surface anchor family protein of
S. agalactiae and incorporated it into the feed. We evaluated the
efficacy of this vaccine in tilapia for a period of 3 months and followed
by a challenge study associated with heat-stress. *