IBR is a highly infectious respiratory disease and while it affects animal health and productivity, it can also affect the trade of animals, semen and embryos. IBR is common worldwide, including in Ireland. However, a number of European countries have managed to eradicate the disease from their herds. In Ireland, an IBR Implementation Group is currently considering the merits of a national IBR programme.

Once an animal becomes infected with IBR, it remains infected for life, despite developing immunity.

Carrier animals play a central role in maintaining IBR in infected herds, where they act as a reservoir of infection

Although these latently infected carrier animals do not continuously shed the virus, at times of stress, such as transport, calving, mixing stock, etc, the virus may be reactivated and can begin to multiply and spread, leading to new infections.

These carrier animals play a central role in maintaining IBR in infected herds, where they act as a reservoir of infection and can introduce infection to previously disease-free herds.

Why vaccinate?

IBR-vaccinated animals will:

  • Show milder clinical signs during primary infection.
  • Shed less virus after initial infection and following reactivation.
  • Be much less likely to reactivate the virus.
  • IBR vaccines are commonly used:

  • In the face of an outbreak, to reduce the impact of IBR in a herd. Live vaccines given intra-nasally offer fast protection. In these circumstances, it may be possible to only vaccinate the group currently experiencing an outbreak.
  • As part of a herd IBR control programme, vaccination can be used to reduce the reactivation and spread of the virus. The vaccine makes it less likely that a carrier animal will reactivate and shed the virus, and that a newly infected animal will become ill and spread the virus. As a result, the number of carrier animals is reduced over time to zero, due to the natural turnover of animals in a herd. To achieve this, a complete and regular herd vaccination will be required.
  • To protect IBR-free herds against infection. Due to the infectious nature of this disease, free herds may decide to vaccinate to reduce the potential impact of an outbreak. A complete and regular herd vaccination programme will be required.
  • To prevent outbreaks of IBR in store and finishing herds. When animals, including weanlings, are bought from multiple sources, there is a high risk of purchasing one or more carrier animals. Weaning, trading and mixing stock are all stressful, and may result in carrier animals shedding the virus.
  • Prevent clinical disease in weaned calves in suckler herds. Where weanlings are kept, some farmers decide to only vaccinate the young stock. While this is beneficial, it will not play a part in the long-term control of IBR in the herd. The most likely source of the virus for these calves is older carrier animals in the herd. Therefore, if we want to prevent older animals being the source of infection for younger stock, they must be included in a vaccination programme.
  • IBR control in a suckler herd

    Remember that vaccinated animals can still be infected when exposed to IBR – therefore, biosecurity is key in IBR control to prevent the virus getting into the herd.

    Another benefit of vaccination is in preventing the incidence of disease at farm level and thereby reducing the need to use antibiotics.

    IBR vaccination may be carried as part of a vaccination programme for respiratory diseases in suckler calves under the Beef Environmental Efficiency Programme (BEEP).

    Top tips

    A vaccination programme for your herd should be made in consultation with your veterinary practitioner.

  • Always read the data sheet provided with the vaccine to make sure it is stored and used correctly.
  • Vaccine storage: vaccines are fragile and must be stored in the fridge (from 2°C to 7°C). Note that prolonged exposure to higher temperatures and/or direct sunlight may adversely affect the vaccine. Do not freeze.
  • Vaccine mixing: Live vaccines require preparation involving mixing a liquid (dilutant) with a powder (the freeze-dried vaccine). Once this is done, the vaccine must be used within a matter of hours (as detailed on the data sheet).
  • Use the correct route of administration: This may be up the nose (intranasal), into the muscle (intramuscular), or under the skin (subcutaneous).
  • Vaccinate the correct animals: Check the age of the animals that you will be vaccinating.
  • Do not vaccinate animals destined to enter a semen collection centre or bull testing station, as they will test positive and be excluded. Use of live vaccines in herds containing such animals must be done with care to avoid accidental exposure.
  • Ensure you are using the correct regime, including two shots for a primary course where required, and correct application and timing of booster vaccinations.