Orf vaccination in sheep

Orf is a common skin disease mainly affecting young lambs in their first year of life. It is zoonotic and can lead to severe systemic reactions in humans.

Orf, also known as contagious pustular dermatitis, is a highly contagious skin condition caused by the orf virus.

In lambs the scabs usually appear around the mouth and nostrils, although can occur around the eyes and ears. It can spread from lambs to the ewes’ udder during suckling.

Lambs affected by orf may find feeding painful, leading to significantly reduced growth rates (Lovatt et al, 2012).

Orf-infected lesions or scabs are at risk of developing secondary bacterial infections. The virus can survive in scabs, which drop off and may persist in dry areas for years.

Vaccination can reduce the severity of orf in affected flocks but must be administered correctly by skin scarification (see product data sheet).

There is one orf vaccine marketed in the UK:

• Scabigard® is a live vaccine for the active immunisation of sheep and lambs against orf to reduce clinical signs

As it is a live vaccine it must only be used in flocks that have had orf diagnosed by a vet, otherwise the scabs formed from its use can contaminate the environment and lead to infection.

The number of doses of vaccine administered has been calculated by multiplying the number of packs sold by the number of doses per pack.

Estimates suggest approximately 50% of lambs are at risk of orf infection due to endemic infection within the flock (Fiona Lovatt expert opinion 2025, Onyago et al, 2014 and Reilly, 2025).

The common industry recommendation is to vaccinate at-risk lambs any time after birth, with vaccination of ewes recommended within at-risk flocks.

The total number of vaccine doses required to protect the national UK flock from orf has been estimated based on the assumption that 50% of lambs and 5% of all ewes receive a dose of vaccine.

The estimated uptake of vaccines to provide protection to sheep against orf has remained stable at just above 30% from 2011 to 2021.

In 2022, the estimated uptake increased to 39% before falling to 16% in 2023. This fall is likely due to a change in licence holder combined with disruption to the supply chain.

The estimated uptake increased to 24% in 2024.

Figure 1. Percentage of sheep vaccinated against orf