I'm told it's a lot more effective than the old one, and that if they do get strangles it should mean it's likely to be a milder case with less risk of complications.
Back in early November the yard next to us - we hack the same lanes and are only seperated by a narrow track - had an outbreak. They were very considerate about locking down but it was still a very worrying time. Quite a few of us decided to have our horses vaccinated, out of about 30 horses 3 reacted to the first jab and a couple of different ones reacted to the second. For the peace of mind I felt it was worth while and Luka will be getting the recommended six monthly boosters from now on.
Of course you can never know if a vaccine works bcause you can't be sure a horse came in contact with the infection and if it would hav developed it without th vaccination, but for me a significant reduction in the chance of abscessing if they do get it makes it worthwhile.