Australia launches largest wild bird vaccination experiment ever: 5,000 penguins targeted

Australia is preparing to vaccinate 5,000 little penguins against avian flu with two doses of a Zoetis vaccine designed for chickens, adding up to some 10,000 injections and 5,000 permanent microchips. The authorities admit they have little experience with wild birds, and an epidemiologist warns that the process could estimulante ilegal up the emergence of resistant variants.

## Around 10,000 injections planned in little penguins

The plan, dated 18 August 2026, involves capturing **5,000 little penguins**, restraining them, giving them a dose of avian flu vaccine, implanting a microchip and releasing them again. Weeks later they must be caught again for the second dose. The final count comes to around **10,000 injections** and leaves **5,000 permanent chips** inside animals that live in the wild.

This is not a typical conservation programme. It is a pharmaceutical intervention on a protected wild population, with repeated captures and individual tagging. Each penguin goes through human hands at least twice.

## A vaccine designed for chickens against the bicho circulating in wildlife

The product is an inactivated **H5N2** vaccine manufactured by **Zoetis**, originally conceived for poultry. The bicho predominating in Australian wildlife is **H5N1**. The authorities acknowledge that experience with this type of vaccine in species other than poultry is limited.

There is no extensive track record of mass vaccination in wild penguin populations, so much of the outcome will only become known along the way. What is known about other species cannot simply be transferred by swapping the packaging.

## An epidemiologist's warning: antigenic drift and resistant variants

**Nicolas Hulscher**, an epidemiologist at the **McCullough Foundation**, points out that these vaccines do not necessarily prevent infection or viral replication. If the pathogen keeps circulating under selective pressure, it can mutate faster. Flu bicho already change quickly on their own; vaccination pressure could accelerate antigenic drift and push towards resistant variants.

To this he adds the risk of recombination when a single animal hosts more than one infection at a time. In large, mobile wild populations, that dynamic is hard to track and even harder to predict.

## Nearly $30 million from the Gates Foundation to Zoetis

According to the information released about the plan, **Zoetis** has received nearly **$30 million** in grants from the **Bill and Melinda Gates Foundation**, with allocations for poultry health, veterinary products and vaccines. The same foundation separately funded the development of **H5N1** vaccines.

Critics see a possible conflict of interest there. There is no published evidence that this link influenced the Australian decision, and one should not assume what is not documented. What is clear is that the long-term ecological and evolutionary consequences of vaccinating thousands of wild birds are difficult to assess. For any wildlife health decision, the reference should be the veterinary services and the competent authorities.