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MSD Animal Health Registers AQUAVAC Strep Sa and NORVAX Strep Si Vaccines in Viet Nam

Health Economics +2 more

VIET NAM - MSD Animal Health (known as Merck Animal Health in the USA and Canada) has announced the registration of the AQUAVAC Strep Sa and NORVAX Strep Si vaccines in Viet Nam.

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The vaccines protect against the two most significant strains of streptococcus, a highly prevalent disease affecting warm water fish.

“We are pleased that we have obtained the registration for AQUAVAC Strep Sa and NORVAX Strep Si in Vietnam. Once available, these products will help producers protect their fish against streptococcus,” said Norman Lim, MSD Animal Health.

“These important vaccines reflect MSD Animal Health’s commitment to supporting producers with effective vaccination and control programs, such as the ‘Strep Control: Your Tilapia Health’ program for tilapia producers.”

Streptococcus affects warm water fish in both marine and freshwater environments and can result in mortality rates in fish as high as 70 per cent.

MSD Animal Health conducted extensive sampling of farms in the world’s most important tilapia-producing regions and found that streptococcus accounted for 70 per cent of all pathogens collected, making it the most prevalent disease affecting tilapia. The two significant species are Streptococcus agalactiae and Streptococcus iniae.


AQUAVAC Strep Sa provides protection against the biotype 2 strain of S. agalactiae, a strain found in Vietnam. In a large-scale field trial in an environment challenged by S. agalactiae biotype 2, AQUAVAC Strep Sa vaccinated tilapia saw a significant improvement in mortality, increased biomass of 15.6 per cent, and feed conversion efficiency was improved by 10 per cent when compared with unvaccinated control fish. In a laboratory test, AQUAVAC Strep Sa protected 85 per cent of fish for over 30 weeks.

AQUAVAC Strep Sa provides specific protection against the biotype 2 strain of S. agalactiae, the main cause of streptococcosis in tilapia in Viet Nam. Fish vaccinated with AQUAVAC Strep Sa are safe for human consumption.

The MSD Animal Health ‘Strep Control Your Tilapia Health’ program, put in place to support farmers with their health management, will help producers confirm the strain and biotype present on their farm, help them develop a specific vaccination and health program and give them access to a variety of tools, equipment and expert advice to put in place a best practice approach and demonstrate performance of the health program.

Producers can consult their MSD Animal Health representative or a fish health professional to learn about MSD Animal Health’s ‘Strep Control Your Tilapia Health’ program and AQUAVAC Strep Sa.

NORVAX® Strep Si

NORVAX Strep Si induces protective immunity in warm water fish against streptococcus caused by S. iniae. NORVAX Strep Si can be administered through a bath immersion for fish 3 grams and above and through injection for fish larger than 20 grams. The vaccine is registered for use in barramundi.

The vaccine has been proven to offer protection for at least 12 weeks in laboratory studies and 34 weeks in field trials.

In a field trial, Asian sea bass injected with NORVAX Strep Si had survival rates of 100 per cent after being challenged with S. iniae, while a control group had survival rates of 37.5 percent. In Asian sea bass receiving an immersion vaccination with NORVAX Strep Si, survival rates were 75 per cent following challenge with S. iniae, compared to a survival rate of 22.5 per cent in the control group.

For more information about AQUAVAC Strep Sa and NORVAX Strep Si, producers can consult their MSD Animal Health representative or a fish health professional.