Vaccines for Finfish Aquaculture

Description of impact

Research undertaken by the Fish Pathology Unit (FPU), Institute of Life & Earth Sciences, Heriot-Watt University demonstrated the utility of an existing MSD Animal Health bivalent fish vaccine in conferring immunity to a wide range of novel variants of the targeted disease.
This led to increased uptake of this vaccine in the face of growing prevalence of these new disease strains across Europe. This has resulted, since 2014, in protection of almost one third of EU rainbow trout production (approximately 142,000,000 fish p.a., valued at over EUR167,000,000 p.a.) against these diseases.

Who is affected

Europe/Fish

Narrative

Prior to the present impact, the development of the novel bivalent AquaVac Relera™ vaccine, based on the original research at HWU FPU, protected ~16% of EU trout production. The subsequent research into cross-protection of the AquaVac Relera™ vaccine against newly emergent disease strains provided clinical efficacy evidence that directly resulted in increased demand for this vaccine in the market, amounting to an average of 142,500,000 doses p.a. between 2014 and 2020 (approximate doubling of supply from the previous period).

This represented protection of some 29.3% of European trout in 2016 (most recent available data), despite European trout production numbers remaining stable over the same period [our estimate of 2016 EU trout production = 196,593 tonnes (FEAP, 2017; http://feap.info/wp-content/uploads/2018/05/production-report-2017_web.pdf), comprising 63 239 tonnes of 1.5 kg fish = 42,200,000 fish and 133,354 tonnes of 0.3 kg fish = 444,500,000 fish; total = 486,700,000 fish, cf. 2012 calculation above; % protected = (142.5/486.7)*100 = 29.3%).

Thus, the proportion of European trout protected by this vaccine effectively doubled during the present Case Study period (2014-2020) in response to increasing emergence of variant Y. ruckeri strains during the same period (Calvez et al., 2014; Hjeltnes et al., 2019).

The AquaVac Relera™ bivalent vaccine is not only a result of HWU FPU research, but the HWU FPU is also responsible for the batch-release regulatory testing of all batches of the AquaVac Relera™ bivalent vaccine to GMP standards (overseen by the UK Veterinary Medicines Directorate as the releasing authority). This makes HWU FPU directly responsible for the supply of all doses of AquaVac Relera™ vaccine to market.

Beneficiaries of this work include the vaccine production company MSD Animal Health, subsidiary of Merck & Co, Inc, USA (one of the top 3 global pharmaceutical companies). FPU research led to the development of the (MSDAH) ReleraTM vaccine against enteric red-mouth (ERM) disease of farmed trout. In particular, a study of cross protection undertaken by FPU examining the efficacy of this vaccine against novel emerging strains of the disease opened up new market opportunities for the company, across Europe between 2014 and 2020. Other beneficiaries also include European trout producers (representing 23.5% of global production in 2016, worth EUR700,000,000; FAO, 2020; European Commission, 2020), European trout processors (reliant on steady fish supply), retailers and consumers (security of food supply).

The farmed fish also gain benefit in terms of their welfare and wellbeing in not being subject to disease and mortality, as do neighbouring wild fish populations resulting from reduced exposure to Y. ruckeri originating from farms. There is also a human and environmental benefit from the use of this effective preventative vaccine due to the reduction of antibiotic use to control infections, since in many areas there is limited resistance of Y. ruckeri to antibiotics (Calvez et al., 2014), which, in the absence of effective vaccine like AquaVac Relera™, could encourage their increased use with the observed increase in novel variant infections. However, greater recourse to antibiotics in turn increases the risk of antibiotic resistance arising in natural bacterial populations and subsequent horizontal transfer of such resistance to medically relevant microbes (Cabello, 2006). Previous evidence shows that effective vaccination can practically eliminate the use of antibiotics in finfish aquaculture (WHO, 2015; RUMA, 2017).

Impact status	Achieved
Impact date	1 Jan 2014 → 30 Apr 2020
Category of impact	Environmental, Economic, Health
Impact level	European