New vaccine boosts sheep health

A new vaccine being developed against ovine enzootic abortion by scientists at the Moredun Research Institute has shown very promising results in laboratory trials, being able to protect against abortion caused by the bacteria Chlamydia abortus without the risk of causing infection in the animal.

One of the main causes of infectious abortion in sheep in the UK, ovine enzootic abortion (also known as chlamydial abortion) is caused by the bacteria chlamydia abortus which invades the placenta during pregnancy.

The disease also represents life-threatening illness and abortion in humans, with pregnant women advised not to work at lambing when the disease is known to be present.

In the sheep population, infected lambs, placentas and excretions provide a source of infection to other susceptible ewes.

The animal health institute said that a high level of environmental contamination from infected ewes in lambing pens or fields played a significant role in the spread of the disease, with a more effective vaccine promising better biosecurity.

Professor Julie Fitzpatrick, Scientific Director, Moredun Research Institute said, “Ovine enzootic abortion is a very serious disease for the sheep industry, and we are hopeful that this new research may lead to a new safe and effective vaccine. In the meantime, we would strongly advise all livestock producers to keep vaccinating their flocks with the currently available vaccines and take advice from their farm vets to reduce the risk from Chlamydia abortus”.

Dr David Dr Longbottom who led the team investigating control measures at Moredun said that the newly developed vaccine was akin to the live variation, but without the ability to grow and cause infections in the host animal stating that this provided an important step towards tackling the transmission of the disease.