Candidate vaccine announced for Schmallenberg

A candidate vaccine that could be used to protect livestock against the deadly Schmallenberg virus has been announced.

Scientists at MSD Animal Health are confident that the vaccine could be developed for production by the end of the year – 12 months earlier than anticipated.

The vaccine is based on a wild-type Schmallenberg strain that has been inactivated and contains an adjuvant that stimulates immunity.

The safety and efficacy of the vaccine has been demonstrated in tests in calves, lambs and pregnant ewes.

Scientists from MSD Animal Health presented the results of the vaccination trials during the 6th Annual Meeting of EPIZONE (an international network of veterinary research institutes working on epizootic animal disease) at Brighton in June.

Veronique Moulin, research scientist at the virological R&D department at MSD Animal Health, said the trials were promising.

“In our studies we looked at the serological response as well as viremia and we have now reported that all vaccinated animals responded with formation of virus neutralizing antibodies,” she added.

“During the trials, all vaccinated animals were protected against Schmallenberg virus infection (complete blockage of viremia), whereas all controls developed viremia after challenge. Moreover, we found a good correlation between antibody titers and viremia.”

Rene Aerts, vice-president Global Biologicals R&D Animal Health, said he saw a potential role for the vaccine in the protection of young breeding stock on infected farms and protection of non-infected farms in risk areas.

“Using our experience gained a few years ago during the fast-track development of the first vaccine against bluetongue 8 virus in just 21 months, we are now on track to develop a vaccine against Schmallenberg virus in an even shorter time,” added Dr Aerts.

“After we isolated the virus last December, we have diligently worked in an integrated and interdisciplinary team at BioSciences Center Boxmeer (The Netherlands) and our manufacturing site in Burgwedel (Germany) to develop this vaccine.

“We anticipate, pending regulatory approvals, to have a vaccine available for our customers by the end of this year.”

The Schmallenberg virus first emerged in Germany last August and then in The Netherlands before spreading to neighbouring countries.

In early 2012, the first cases were found in the South and East of England, diagnosed following the testing of deformed lambs. Now there are reported cases in 27 counties.

Latest figures from the Animal Health and Veterinary Laboratories Agency (AHVLA) show that there are 274 UK farms reporting the virus, including 52 in cattle and 219 in sheep.

Three premises that reported the virus in sheep earlier this season are now also reporting cases in cattle. Oxfordshire reported its first case last month.

The Schmallenberg virus causes brief, mild to moderate disease in adult cattle, and life-threatening defects in cattle, sheep and goats in utero.

The AHVLA has warned cattle farmers, in particular, to continue to watch for symptoms of the virus in adult cattle, including fever, milk yield reduction, and diarrhoea.

“MSD will have to prove that the vaccine is both safe and efficacious,” said Peter Mertens, head of vector-borne diseases at the Institute for Animal Health.

“It will be quite a tight deadline to get the vaccine licensed before the end of the year, but it’s possible.

“The virus is still circulating this year in cows near Bordeaux, in south-west France, so it hasn’t gone away. But we don’t know yet whether it will return to the UK this autumn.”

Prof Mertens said the vaccine would need to be “up and running” quickly to tackle the disease in livestock this autumn, or it would not be ready to protect sheep and calves next spring.

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