# An Overview of Avian Vaccination Options in Zoological Collections in Europe

## TL;DR

This paper reviews the use of vaccines in zoo birds, highlighting the lack of species-specific data and the need for more research to improve vaccination strategies for non-domesticated birds.

## Contribution

The paper provides a comprehensive review of avian vaccines used in zoos, emphasizing the need for species-specific validation and evidence-based strategies.

## Key findings

- Most avian vaccines are developed for poultry and used off-label in zoo birds with limited safety and efficacy data.
- Vaccine use in zoo birds should be guided by risk assessment, legislation, and species-specific considerations.
- More research is needed to support evidence-based vaccination strategies for endangered bird species in zoos.

## Abstract

Vaccination can help protect zoo birds from many infectious diseases, but most available avian vaccines are developed for poultry rather than for the diverse species kept in zoological institutions. As a result, veterinarians often use off-label vaccines, even though there is limited evidence of their safety and effectiveness in non-domesticated birds. This review summarizes all published information on vaccines used or suitable for use in zoo-housed birds. Although many commercial vaccines are safely used in poultry, data about their use in non-domesticated birds are scarce, and immune responses may vary greatly between avian species. Good biosecurity, careful risk assessment, and species-specific considerations remain essential. More research is urgently needed to support evidence-based vaccination strategies for endangered and valuable bird species housed in zoos.

Captive bird populations in zoological institutions face unique disease risks due to close interspecies contact and human interaction. Vaccination is widely used as a prophylactic measure. However, most available vaccines are developed for poultry and are used off-label in non-domesticated birds, often without species-specific safety and efficacy data. This review provides a comprehensive overview of vaccines reported in zoo-housed birds for major viral, bacterial, and fungal pathogens. This review highlights that for most vaccines, evidence of safety and effectiveness is limited. Vaccine use should therefore be guided by risk assessment, relevant legislation, and institutional priorities, and should integrate species-specific data on vaccine safety and effectiveness, disease susceptibility, and local epidemiology. Extensive research and species-specific validation are essential to improve preventive health strategies in avian conservation programs.