Bluetongue vaccine might 'not be enough' to control outbreaks - expert
With the suspected case of bluetongue being reported recently in Northern Ireland, many farmers will be concerned about how they can protect their herds if the disease spreads.
While a bluetongue serotype 3 (BTV-3) vaccine is available to NI farmers upon being granted a licence, there is currently no vaccine in place for farmers in the Republic.
Dr. Gerald Barry, assistant professor of virology and deputy director of the One Health Centre at University College Dublin (UCD), told Agriland's AgriFocus podcast that a vaccine alone might not be enough to control bluetongue outbreaks.
He stressed the importance of robust surveillance to detect the disease among herds before it can spread.
Vaccine
When an animal is suspected to be infected with bluetongue, Dr. Barry stated that there is no direct, antiviral treatment that can be administered, and farmers are recommended to remove the animal from the herd to prevent further spread.
He explained: "Because bluetongue is a notifiable virus, the animals would be removed from the herd and they can go directly to abattoirs as there isn't a food safety concern."
"There would not really be a treatment used against this virus - it is more about control, cull, and eradicate."
With the expectation of bluetongue vaccination to be introduced across the entire island of Ireland if the virus continues to spread, Dr. Barry has warned that the current vaccine is not "perfect".
He outlined that while the vaccine can reduce the amount of bluetongue virus within an animal, it does not block infection and infected animals can still transmit the virus to others through midges.
Surveillance
Dr. Barry said: "The challenge here is that you can't use a vaccine alone to control an outbreak - because if you do, you are never really going to stamp it out because the vaccine allows onwards transmission from animal to animal."
He added that when bluetongue previously arrived in other countries, such as France, vaccinations were found to be not enough to control a outbreak, with some countries now not even recommending the use of vaccines in certain cases.
Directing attention towards surveillance should be a priority, according to Dr. Barry.
He noted: "Really at the moment, the focus should be on rapid and aggressive surveillance for early detection of cases to try and limit its impact on a particular herd, but also limit its potential spread to other herds."
