The efficacy of immersion as opposed to oral vaccination of Penaeus indicus larvae against Vibrio harveyi

Significant levels of protection were conferred to Penaeus indicus larvae for at least 48 h when either fresh or freeze-dried Vibrio harveyi vaccines were administered by immersion, but not when such vaccines were administered orally. The degree of protection offered increased with the virulence of the pathogen from which the vaccine was made. Vaccination of larvae also induced cross-protection against challenge by other V. harveyi strains. (C) 1999 Elsevier Science B.V. All rights reserved.