New vaccine against bird flu to be tested in Swiss zoos

The past two years have been particularly challenging as Europe battles the largest avian influenza epidemic on record. Keystone / Mads Claus Rasmussen

A new vaccine against bird flu has received approval by the Federal Office for the Environment (FOEN) for testing in two zoos in Bern and Basel.

The Federal Office for the Environment (FOEN) has given approval to the Swiss Institute for Virology and Immunology (IVI) to test the effectiveness of a genetically modified vaccine against bird flu at the Bern Animal Park and Basel Zoo. The trial also aims to determine any side effects as well as safety aspects for people.

The past two years have seen Europe battling the largest avian influenza epidemic on record. Avian flu has been a cause for concern in Switzerland, where more and more birds and mammals are affected by the H5N1 virus. An outbreak occurred in the pelican enclosureExternal link at the Bern Animal Park at the end of 2022.

Cases are still being detected

As recently as February, a new case of bird flu was detected in the canton of Zurich. Experts expressed concern about a “real pandemic”, fearing a mutation of the virus. This led the federal government to extend protectionary measures against bird flu until March 15, 2023.

+Bird flu becomes cause of growing concern in Switzerland

There are still questions surrounding the mutation and transmissibility of the virus from animals to humans, though the World Health Organisation considers the risk to humans to be low.

Key finding could lead to lifting of vaccination ban

The IVI has developed its experimental viral vaccine vector based on a replication-impaired vesicular stomatitis virus (VSV), which has had a key gene removed and replaced with a gene from the H5N1 avian flu virus.

When tested, the vaccine was found to “completely protect vaccinated chickens against lethal infection with H5N1”, the institute’s website states.External link

Currently, there is a vaccination ban in place for poultry production. The reason for the ban is that serological tests, or anti-body tests, could not distinguish between vaccinated animals and infected animals. The vaccine developed by IVI makes it possible for a serological test to make this distinction, IVI says. This could lead to lifting the vaccination ban for poultry production.  

The Institute of Virology and Immunology is based in Bern and is a part of the Swiss Federal Food and Safety and Veterinary Office (FSVO). The IVI laboratory works on the diagnosis, surveillance and control of highly infectious diseases, such as avian and swine flu, and monitors the potential of infectious disease transmission to humans.

The trial in Bern and Basel is planned to take place between 2023 and 2026.