## 5 Current Licensed Vaccines for Viral Diseases  
In comparison to bacterial infections, viral disease outbreaks are more difficult to control due to a lack of anti-viral therapeutics and information regarding the mechanism of viruses, specifically, how they impact the organism. Several research trials have been conducted on the latter and have provided crucial information that has allowed companies and academic organizations alike to develop effective vaccines. Table 3 displays a list of available licensed viral vaccines for fish. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Virus** & \begin{tabular}{c} **Type of** \\ **(RNA/DNA)** \\ \end{tabular} & **Fish Host** & \begin{tabular}{c} **Trade Name** \\ **(If Applicable)** \\ \end{tabular} & \begin{tabular}{c} **Type of** \\ **Vaccine** \\ \end{tabular} & \begin{tabular}{c} **Delivery** \\ **Method** \\ \end{tabular} & \begin{tabular}{c} **Licensed for** \\ **Use in the** \\ **Following** \\ **Countings** \\ \end{tabular} & **Description** \\ \hline SAV & RNA & Atlantic salmon & Norvax Compact PD & Inactivated & Intraperitoneal & Norvay & A monovalent vaccine which \\  & & & & Injection & Chile & contains an inactivated strain of \\  & & & & & UK & SAV subtype 1. \\ \hline SAV & RNA & Atlantic salmon & Aquavac PD7 & Inactivated & Intraperitoneal & Norvay & \begin{tabular}{c} A polyvalent vaccine which \\ contains seven strains to protect \\ against \\ pancreatic disease, infectious \\ pancreatic necrosis, furunculosis, \\ voltriters. Specifically, to protect \\ against SAV, it contains an inactivated strain of SAV subtype 1. \\ \hline SAV & RNA & Atlantic salmon & Aquavac PD3 & Inactivated & Intraperitoneal & UK & \begin{tabular}{c} A polyvalent vaccine which \\ contains an inactivated strain of \\ SAV subtype 1, as well as infectious \\ pancreatic necrosis \\ and furunculosis. \\ \end{tabular} \\ \hline SAV & RNA & Atlantic salmon & Alphaject Micro 1 PD & Inactivated & Intraperitoneal & UK & \begin{tabular}{c} A monovalent vaccine which \\ contains the inactivated SAV \\ subtype 3, the SAV strain most \\ dominant in Norway. \\ \end{tabular} \\ \hline IPNV & RNA & \
\begin{tabular}{c} Atlantic salmon, \\ rainbow trout \\ \end{tabular} & Alphaject 1000 & Inactivated & Intraperitoneal & Chile & A monovalent vaccine containing \\  & & & Injection & Norway UK & an inactivated form of the virus. \\ \hline IPNV & RNA &
\begin{tabular}{c} Atlantic salmon \\ salmon \\ \end{tabular} & Birnagen Forte & Inactivated & Intraperitoneal & Canada & A monovalent vaccine containing \\  & & & Injection & UK & inactivated bacterins and virulins. \\ \hline \hline \end{tabular}
\end{table} 
Table 3: List of worldwide licensed viral vaccines. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
Koi Herpes Virus (KHV)  
The koi herpes virus causes significant mortality in common carp types. It is a double-stranded DNA virus that belongs to the family _Alloherpresviridae_. The virus is replicated within a host organism and induces mucosal sloughing and necrosis [117]. Autogenous, inactivated vaccines have been developed and administered to protect carp in countries such as Germany and Indonesia [118]. DNA vaccines are being tested and developed, and _Arthrosipira platensis_ is being explored as an alternative to prevent an outbreak of KHV and reduce its transmission rate [118; 119; 120; 121]. Infectious hematopoietic necrosis virus (IHNV)  
\begin{table}
\begin{tabular}{p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt}} \hline \hline
**Virus** & \ \begin{tabular}{} \end{tabular}  & **Fish Host** & \begin{tabular}{} \end{tabular}  & **Type of** \\
Infectious hematopoietic necrosis virus is a single-stranded RNA virus belonging to the family _Rhabdoviridae_ and the genus _Novihabdovirus_. The virus can be isolated into three genogroups (U, M, and L), with the M genogroup containing a higher genetic diversity and a higher mortality (CFSPH) [122].