By Badal yadav M. F. SC. (Fish nutrition and feed technology) Kufos

1. SUBJECT:-AQUATIC ANIMAL HEALTH MANAGEMENT (AAH503)(2+1)
TOPIC:- VACCINES AND ADJUVENTS USED IN AQUACULTURE
SUBMITTED BY
BADAL YADAV
M.F.Sc. (FNFT)
ROLL NO.~ AQC-2021-21-03

2. INTRODUCTION
Disease is one of the most important limiting factors in aquaculture.
However, all facilities are vulnerable to disease outbreaks because many pathogenic
(disease causing) organisms (e.g., bacteria, viruses, fungi, and parasites) are
opportunistic and present in the environment, or may be found on some fish that are
not showing signs of disease (carriers).
Two approaches to disease prevention that historically have been used in other
animal industries are vaccines and immunostimulants.
The use of vaccine has entered in the field of aquaculture recently because of the
intensive culture system , many industries have resorted to the routine use of
vaccines which confer a high degree of protection when correctly used.

4. What is a vaccine?
A vaccine is any biologically based preparation intended to establish or to
improve immunity to a particular disease or group of diseases.
Vaccines work by exposing the immune system of an animal to an
"antigen"—a piece of a pathogen or the entire pathogen—and then allowing
time for the immune system to develop a response and a "memory" to
accelerate this response in later infections by the targeted disease-causing
organism.

5. The Properties of the ideal vaccine
The ideal vaccine:
 It is safe for the fish, the persons vaccinating the fish, and the consumer.
 Its protects against a broad strain or pathogen type and gives 100% protection.
 It provides long-lasting protection, at least as long as the production cycle.
 It is easily applied.
 It is effective in a number of fish species.
 It is cost effective.
 It is readily licensed and registered .

6. ADJUVANTS
Adjuvants are pharmacological or immunological agents capable of modifying the effect
of other agents, such as drugs or vaccines.
Adjuvants are virtually useless if given alone, but can serve to make a vaccine much
more effective.
When given together with a vaccine, the adjuvant will stimulate the immune system and
increase its response to the vaccine.
Exactly how adjuvants work remains unknown. Aluminium salt, virosomes and certain
oils are all commonly used as adjuvants for vaccines.
FUNCTION
(i) increasing the immunogenicity of weak antigens.
(ii) enhancing the speed and duration of the immune response,
(iii) modulating antibody avidity, specificity or subclass distribution.

7. Types of vaccines
Killed whole cell vaccines
Killed whole cell vaccine is the suspension of host or chemically killed pathogens that are
able to induce specific protective immune response against those pathogens when
administered into the host.
These have been great use in controlling some of the important fish bacterial pathogens such
as Vibrio anguillarum, V. salmonicida etc.
Live attenuated vaccines
Live, attenuated vaccines are comprised of live micro-organisms (bacteria, viruses) that have
been grown in culture and no longer have the properties that cause significant disease. Live
attenuated vaccines will stimulate additional parts of the immune system (i.e., a cell
mediated, as well as a humoral [antibody] response).

8. Recombinant DNA - based vaccines
Recombinant DNA technology is defined as formation of new combinations of
genetic material by insertion of nucleic acid molecules produced outside the cell ,
via a vector system .
It also termed as ' recombinant DNA - based vaccines ' or ' new generation
vaccines '.
Four different types of vaccines based on recombinant DNA technology have
been developed so far which include:
(i) Recombinant immunogenic protein vaccines or epitopes purified from
vectors carrying the gene of interest produced in prokaryotic or eukaryotic
expression systems,
(ii) Peptide Vaccines
(iii) Live Vaccines
(iv) DNA Vaccines

10.  Inactivated vaccine
 Toxoid vaccine
 Subunit vaccine
 Conjugate vaccine
 Monovalent and multivalent vaccines

11. MODE OF VACCINE ADMINISTRATION
There are three methods of vaccination in fish.
INJECTION DELIVERY SYSTEM

12. ADVANTAGES
 Long duration of protection almost for over a year.
 Every fish in the population has received the vaccine and at the correct dose.
 Multiple antigens can be combined in a single vaccine and therefore can be done
in a single administration.
 Superior to any other methods, however from a practical point of view , it can be
applied for a fish of 10g or more.
DISADVANTAGES
 Unsuitable for small fish.
 Needs sophisticated machinery or large skilled workforce.
 Significant handling stress and risk of post vaccination fungal infections.

13. IMMERSION VACCINATION
DIP VACCINATION

14. BATH VACCINATION

15. ADVANTAGES AND DISADVANTAGES OF IMMERSION
VACCINATION
 Suitable for mass vaccination of all sizes of fish.
 Reduced stress for fish.
 Lower labour costs.
 Less risk to vaccination team.
 Major disadvantages are the large amount of vaccine required and lower
level of protection and duration of immunity.

16. ORAL DELIVERY SYSTEM OR ORAL VACCINATION
ADVANTAGES AND DISADVANTAGES OF ORAL VACCINATION
Advantages:
easiest method for mass vaccination of all sizes of fish.
Saves labour and avoid stress
Disadvantages:
Protection generally weak and for short duration.
Large quantities of antigen required.

17. MAIN DISEASES CONTROLLED WITH VACCINATION

20. CONCLUSION
 Aquaculture continues to expand , disease problems will increase.
Therefore, disease research and the implementation of new disease control
concepts are important to maintain sustainability.
The development of an effective vaccine is a complex process. One of the
prerequisites understanding of basic epidemiology of disease and the immune
system of the target species is required.
 A number of vaccines have been is used by the salmonid industry for
decades, however , commercial vaccine development for other aquaculture
sectors , including warm water fish, is still quite limited.

21. REFERENCES
https://www.ncbi.nlm.nih.gov/pubmed/9890041
https://www.hpra.ie/docs/default-source/default-document-library/fish-
vaccine-overview.pdf?sfvrsn=0
Fish Vaccination: A Health Management Tool for Aquaculture
Arun Sudhagar S1, Ferose Khan2 and Linga Prabu D2 -
http://aquafind.com/articles/Vaccination.php
Fish vaccines – Alexandra Adams
https://www.pharmaq.no/products/vaccination-of-fish/