Schmallenberg vaccine.

greysides

There will shortly be a Schmallenberg vaccine available, Bovilis SBV. The price per dose is in the area of €3-€4. It is a POM product, only available on prescription. The only reason it is available here, while the rest of Europe is still waiting, is that the UK have the facility to provisionally license a vaccine once the vital testing has been done but before all full licensing provisions have been met. For example, those relating to the safety of it's use in male breeding animals and the duration of it's efficacy re-boosting. Irish legislation allows us to use it under special provisions as it is being used in the UK. So effectively we're piggy-backing on their use/legislation.

A meeting was held in Gorey last night with speakers from the IFA, the local regional vet lab, a Co. Tipp. vet who also farms and drug company representatives.

MSD, the manufacturers of the SBV vaccine and hosts for the evening, have been running a series of meetings explaining the disease and control measures. Their representative mentioned they were a company that had a lot of products for sheep, despite being based in the sheep-shy USA, in contrast to most other big pharmaceutical companies.

Two things were made clear during the discussions. One, that our Dept of Agriculture was tackling the situation a lot better than the UK ministry. They are continuing to do tests to monitor it's spread through bloods collected during Brucellosis testing and through lab PMs. Generally Dept interest in disease is confined to 'notifiable diseases' which have legislative implications if present. Schmallenberg disease is not notifiable. There has been difficulty in the UK getting funds to do research.

Secondly, that there are very few established facts in dealing with SBV. Quite simply, there hasn't been the passage of time necessary to do the research or have learnt from experience what the answers are.

The major question everyone wanted answered was 'Do we need to vaccinate?'

As you might have guessed, there isn't a simple answer. Up until recently you would be forgiven for assuming that if you've had the disease in your herd or flock, you have serological evidence of it's presence in your animals or, even, you know it has been through your area that you wouldn't need to vaccinate.


Major cold water has been thrown on this assumption/hope. A meeting held recently with experts from Pirbright in the UK presented evidence that in a herd/flock while many might have been exposed it was far from certain that you could assume all were exposed. This was to the extent that the vet speaking intended to vaccinate his own animals despite having had the disease this last Spring.

Midges were described as 'aerial plankton', going where the wind took them. They only stay aloft when wind speeds are slack (<10km/hour, I think) but can theoretically stay up for up to 16 hours at a time.

Hill top areas where there would be more wind movement should result in lesser exposure while the stagnant air in river valleys would allow for a greater risk to animals.

It is also assumed that exposure to the wild virus is protective for life. It is known natural exposure gives a strong immunity but animals first exposed have not been exposed for long enough yet to go any further.

The period of risk has, again, not been nailed down. Money and time being needed to run the experiments necessary. MSD is the only company to bring forward a vaccine showing the general apathy to spending money on this disease.

In rough terms, the risk period for sheep is the second month of gestation and for cattle is months three, four and five. The period of risk, essentially, runs from the time the cleaning is formed until the blood-brain barrier of the foetus becomes impenetrable to the virus.

This means that the vaccine is likely too late coming available for a lot of the cattlemen for this year but may be of value to sheep farmers. The vaccine is not licensed for use in animals already pregnant as the necessary work proving it is safe has not been done yet.

At the moment the regime is a single 2ml dose to sheep and a two dose primary course for cattle. Immunity being strong three weeks after the last injection.
There is a slight difference in vaccine claims for the two species due to regulations re-licensing in the UK and over time the sheep instructions may change to two 1ml injections and allow the sheep claim to be upgraded. The vaccine boosts any natural immunity already present.

The speakers were of the opinion that this virus while sharing many features of Akabane Disease virus is a very different virus and it's quite likely the full spectrum of its effects may turn out to be different to the those of the Akabane virus.

There was the idea expressed that this disease may 'burn out' after 4-5 years as the number of non-exposed animals and therefore susceptible animals becomes very small, meaning it runs out of hosts.
It was reported that the effects of SBV in the UK were less this year than the previous.

In regard to control measures, the alternative approach would be to prevent contact/exposure during the critical period.... while theoretical measures might prevent exposure (housing in sheds with air gaps of ,1mm), in the real world there was nothing really effective. Dipping and using PourOn was not going to be protective. Help a little perhaps but not going to be good enough to rely on. Might make the farmer feel better.


So were there any conclusions made?

Basically, NO!

The decision to vaccinate or not has to be an individual decision made after weighing up the risks.

The IFA sheep representative, who had SBV in his flock last year within the more normal 2-5% prevalence rate, had decided not to vaccinate but stressed he was aware he was taking a calculated 'gamble'.

The vet in the panel had decided to vaccinate.

You choose.

The only good news was when it was said that only female midges bite, looking for the blood meal they need in order to lay eggs. This is of great comfort to anyone being bitten in the evening by midges (only half the population are trying to bite you) but of of less comfort when it was mentioned that exposing your arm for an hour in some areas of Scotland has resulted in 30,000 strikes (I think it was 30,000 and not 3,000..... personally I wouldn't have waited for it to go above 3).

There is information available here from MSD.

Lastin

thanks Greysides I was to go but could not make it, any word on duration of immunity following vaccination? or how far in advance of breeding it must be used? Just out of interest how many turned up 7 30 was a bit early

mahoney_j

Heading to meeting in limerick re sbv.unsure as to wether ill vaccinate next year or not.see how next spring goes first!!on subject of start time,think 7.30 is perfect time.should be all wrapped up by 9.30 or10 .nothing irks me more than meetings that are meant to kick off at 8 or8.30 not starting till 9 and still having lads strolling in at 9.15 or 9.30 and asking questions on topics already covered.ifa meetings are cruel for this

greysides

Lastin wrote: »

thanks Greysides I was to go but could not make it, any word on duration of immunity following vaccination? or how far in advance of breeding it must be used? Just out of interest how many turned up 7 30 was a bit early

Lastin, duration of immunity is undetermined, not enough time has passed for it to have been determined. It needs to be completed three weeks before breeding as it hasn't yet been proven to be safe in pregnant animals.

7.30 was a bit of a rush for me too. I got a good half an hours kip in before it started. Went on until about 10.15.

By and large it a good talk. I know there wasn't a huge amount of exact answers given but everyone gave honest replies to the questions asked to the best of the available knowledge.

There were comparisons to Bluetongue in some responses. But BT doesn't spread as rapidly. It doesn't spread from the midges to their eggs to their larvae and multiply that way. Vaccines for BT were already available for other serotypes so the development of a vaccine for BT8 was much more easily done. Ring vaccine stopped BT dead in England and it hasn't cropped up there again since. We've only a vaccine now. By Feb 2013 it had already spread from the south and south-east to a line joining Dublin and Limerick. I'd say that it has spread a lot further by now.

There was mention of a 'vector-free period' at one point, in relation to midges. That was an old assumption, pre-BT. We now know that midges while most active March-November are still about the other months, about 10% activity, I think.

During the BT episode it was discovered that the southern European midge species would not enter houses/sheds. The northern European species has no such inhibitions..... maybe the reason THEY were the northern European species.......................

Hence why I say it would be interesting to know the current areas where the wave is breaking.