Vaccines, wormers and their effect on immunity aginst lungworm

Combining vaccination and worming is an effective means to prevent husk in cattle.

The problem

For every 1000 farmers who started vaccinating last year in response to an outbreak or a perceived threat, 1450 thought the risk so small that they were prepared to stop instead! In some areas of very high dairy cow density, such as Cumbria, the number of animals in which vaccination is being discontinued is almost identical to those having to start afresh. Both groups are very large – amounting to a quarter of all vaccinated stock. Clearly farmers are confused.

We can only assume that many of the lapsing users have interpreted the claims of some wormers that they "allow natural immunity to develop" as a claim, in itself, to "create immunity" – something which of course only a vaccine or a (risky) natural challenge can do. In current financial circumstances, the invitation to stop using any medicine is attractive. Meanwhile, we experience an ever-growing epidemic.

The solution – Wormers and vaccination

Wormers, of course, are a vital part of modern cattle farming, and will remain a fact of life. As they become increasingly varied and sophisticated, vets must now show how wormers can work alongside vaccination to reduce the growing problem of husk.MSD Animal Health, as the only supplier of both vaccine and sophisticated wormers, is uniquely placed to help advise.

Ultimately we must help the farmer to devise comprehensive ‘wholefarm’ strategies for parasite control, that are both cost-effective and sufficiently protective in the longer term. To achieve this, we have to investigate how the various wormers permit natural challenge; and how these ‘windows of opportunity’ for parasitic infection tie in with the lifecycle of the lungworm itself.

Mature lungworms in the trachea and lungs of a cow