Viruses versus vaccines: the economics of herd immunity
Towards the end of 2011 some farmers in Northern Europe reported reduced milk yields and some animals not making the expected weight at slaughter. The impact had been notable but not dramatic and the reason was unknown. With the coming of spring 2012, the farming community was looking forward to lambing and calving season. But on a small number of farms, a potentially devastating situation began to unfold. Healthy, pregnant animals unexpectedly had abortions or had stillborn offspring with fused limbs, malformed bodies, and misshapen heads. The culprit: Schmallenberg virus (SBV).