# Sheep and goat pox: vaccines and vaccination scenarios to control the epidemics in Greece and Bulgaria in 2025

## TL;DR

This paper evaluates how vaccines and vaccination strategies can help control sheep and goat pox outbreaks in Greece and Bulgaria.

## Contribution

The study introduces a model-based evaluation of vaccination scenarios for controlling sheep and goat pox in Europe.

## Key findings

- Live attenuated vaccines provide strong protection (80%-100%) against sheep and goat pox.
- Vaccination reduces outbreak size and geographic spread more effectively than culling alone.
- A two-year vaccination campaign can lead to SGP eradication one year faster than non-vaccination strategies.

## Abstract

Sheep pox and goat pox (SGP), caused by Capripoxviruses, have re‐emerged in Europe with unprecedented intensity during 2024–2025, particularly affecting Greece and Bulgaria and posing an increasing risk to neighbouring countries. Despite established EU control measures, the scale and persistence of outbreaks may suggest certain delays in detection or reporting and a potential role of animal movements, both authorised and uncontrolled, in sustaining transmission. This assessment reviews the effectiveness and safety of commercially available SGP vaccines and evaluates the potential impact of vaccination strategies on epidemic control and eradication. A literature review and experimental data from the EURL for Capripoxviruses confirm that live attenuated SGP vaccines based on sheep pox virus strains, including RM65, Romania and Bakirköy sheep pox strains, provide strong protection (typically 80%–100%) and substantially reduce viral replication and shedding in sheep. Safety profiles are generally favourable, though mild post‐vaccination reactions may occur and adherence to recommended dosing is essential. The risk of vaccine virus transmission is minimal when standard precautions are followed. Using demographic and outbreak data from Bulgaria, a stochastic spatial kernel model was applied to simulate SGP spread and assess vaccination scenarios. Results indicate that rapid detection and culling alone can control epidemics within 1–2 years, but vaccination markedly reduces outbreak size and geographic spread. Regional vaccination carries a risk of viral escape unless strict movement controls are enforced, whereas nationwide vaccination provides more robust containment. A two‐year vaccination campaign combined with standard control measures is predicted to achieve eradication 1 year earlier than non‐vaccination strategies. In Greece, the complexity of transmission dynamics and multiple epidemic clusters suggest that targeted or nationwide vaccination would be necessary. Overall, vaccination – particularly when integrated with early detection, rapid culling and movement restrictions – offers a critical tool for controlling and potentially eliminating SGP in affected regions.