By Sybille de La Hamaide

PARIS (Reuters) - A bird flu vaccination campaign launched in France in 2023 has enabled the country's poultry production to recover to levels not seen since outbreaks of the virus wiped out tens of millions of birds, producers said on Tuesday.

Avian influenza (HPAI), or bird flu, is a viral disease that has ravaged poultry flocks worldwide in recent years. There has also been evidence of transmission beyond birds, including dairy cows and farm workers in the United States.

France requires vaccination of ducks, the most sensitive species to the virus, making it the world's first large poultry exporter to launch a nationwide bird flu vaccine campaign.

But some countries have put restrictions on French imports as a result - concerned that vaccinated birds pose a risk as they may not show signs of infection, meaning it is impossible to determine whether the virus is in a flock.

Despite such trade concerns, the chair of French poultry industry group Anvol, Jean-Michel Schaeffer, said "vaccination is a success".

"Between last year and this year, all species are increasing because we have avoided major health crises. This has allowed farmers to return to full production," he told reporters.

In 2024, French poultry output rose 12.1% from the previous year after gaining 2% versus 2022. It is now 1.1% above the "pre-crisis level" of 2019, a year with relatively few bird flu outbreaks, Anvol said.

The French poultry producers' comments come days after the U.S. Department of Agriculture (USDA) gave conditional approval to Zoetis to use its bird flu vaccine in poultry.

The U.S. had built a poultry vaccine stockpile after major bird flu outbreaks in 2014 and 2015, though the vaccines were never used due to trade concerns.

(Reporting by Sybille de La Hamaide; Editing by Helen Popper)