Is the time approaching when we will also have vaccines for avian flu? Apparently so, at least according to the findings of a study conducted by Wageningen University & Research (WUR), based in the Netherlands. The research attested that two turkey herpes virus (HVT)-H5 vaccines were effective against Hpai, the highly pathogenic avian influenza in laying hens: they can be administered in eggs or to day-old chicks in the hatchery. Researchers observed that both vaccines were able to prevent 100 percent of the disease, mortality after infection, and virus spread among birds with Hpai H5N1 virus. 

The study tested the efficacy of four commercial vaccines from veterinary medicine companies on laying hens:

• HVT-H5 vaccine from Ceva Sante Animale;
• HVT-H5 vaccine from Boehringer Ingelheim Animal Health;
• DNA vaccine from Huvepharma;
• Nobilis vaccine from Merck Sharp & Dome (MSD).

The study was aimed at determining whether the virus would spread from infected to uninfected chickens. Each vaccine was administered to 10 laying hens, five infected with Hpai and five uninfected: well, the two HVT-H5 vaccines were 100% effective. The researchers did not evaluate whether or not the vaccines are effective in preventing the disease after Hpai infection has already occurred: the two vaccines found to be effective are already on the market in several countries, but have not yet been registered in the Netherlands or the European Union.

"The so-called HVT-H5 vaccines offer protection against disease symptoms in laying hens and prevent the spread of the virus", explains Nancy Beerens, head of the National Reference Laboratory for Avian Influenza and Newcastle Disease at Wageningen Bioveterinary Research (WBVR). According to Beerens, the study results do not mean the vaccines are effective in poultry farms, however, the Dutch Ministry of Agriculture, Nature and Food Quality plans to conduct an in-depth field study in the summer of 2023.

"It is important to test whether vaccines work well under field conditions on poultry farms, how long the vaccines protect and whether one vaccination is sufficient -she adds-. There are still some hurdles to overcome, but the results of our research are an important first step toward vaccination against avian influenza virus in poultry".