News Archive

5 September 2012 BOXMEER (the Netherlands)

AQUAVAC IridoV Receives First Market Authorization in Singapore

BOXMEER (The Netherlands), September 5, 2012 — Merck Animal Health (known as MSD Animal Health outside the United States and Canada) has obtained approval from the authorities in Singapore to begin marketing AQUAVAC® IridoV, a new inactivated vaccine for reducing mortality due to iridovirus disease (genus Megalocytivirus) in marine fish, tilapia and other susceptible fish.

AQUAVAC IridoV, an oil-adjuvanted vaccine, is administered intraperitonealy as a single-injection dose to fish weighing no less than 5 grams. According to Merck Animal Health, onset of immunity to iridovirus has been demonstrated 10 days after vaccination at a water temperature of 27°C. Studies have shown the vaccine’s duration of immunity to be at least 15 weeks after a single dose.

Strikes early
Iridovirus disease is an infectious disease that generally strikes fish in the nursery but may continue well into the grow-out stage. “If left uncontrolled, iridovirus has been known to cause up to 90 percent mortality in fingerlings within a month or so after stocking. In certain situations the disease can also be chronic without an obvious mortality peak,” said Neil Wendover, technical director for warmwater aquatic species at Merck Animal Health.
Fish infected with iridovirus are darkened and may be seen swimming lethargically at the sides of fish cages. Gills and internal organs, particularly the liver, turn pale. Iridovirus can also cause immunosuppression, which makes fish susceptible to other diseases. “There is no treatment for iridovirus, so vaccination - next to good husbandry - is the only option for managing this costly disease,” Wendover added.

Warmwater fish research
According to Siow Foong Chang, site manager for Merck Animal Health’s dedicated aquaculture research facility in Singapore, AQUAVAC IridoV is the second aquaculture vaccine licensed in an Asia-Pacific country this year by Merck Animal Health, the world’s largest producer of aquatic health products. In Indonesia, the company recently launched AQUAVAC Strep Sa, an inactivated vaccine that aids in the protection against Streptococcus agalactiae infections in tilapia and other susceptible fish. “The effort is part of our expanded commitment to the aquaculture industry in Asia, which produces more than 75 percent of the world’s farmed fish,” Chang commented. The company is pursuing registration of these vaccines in other Asia-Pacific markets as well.

Now in its 12th year, Merck Animal Health’s aquaculture R&D center in Singapore has made significant contributions to the identification, understanding and management of fish diseases in the region, Chang added. The laboratory has also played a pivotal role in developing the first range of oil-adjuvanted injection vaccines for yellow tail and amberjack in Japan, as well as successfully developing new vaccines for tilapia and marine fish. “Working closely with customers and our global and regional technical services teams, our R&D group continues to work on new vaccines and health products for the warmwater aquaculture industry worldwide.” he concluded.

For more information about AQUAVAC IridoV and other aquatic health products, go to, email to or contact your local Merck Animal Health representative. In the Asia-Pacific region, call +65 6397 1121.