May 22, 2007

 

Imugene's poultry vaccine achieves close to 100 percent effectiveness

 

 

Imugene says US trials of its bird flu vaccine for chickens are almost 100 percent effective.

 

The trial group of nine chickens received the first dose of Imugene's vaccine injected directly when they were still unhatched, followed by an oral booster dose when the chickens were seven days old.

 

The chickens survived exposure to a high dose of a highly pathogenic Asian strain of the H5N1 bird flu virus at age 21 days.

 

In the control group, seven out of eight chickens died within 48 hours of the same exposure.

 

Another group received only a single injection of Imugene's vaccine into the eggs with no additional oral booster dose. The study found that the single dose vaccine was successful in achieving 82 percent protection (nine of 11 birds survived) against the challenge at the age of only 14 days.

 

Imugene said the core objectives of the trial, undertaken at Benchmark Biolabs in Nebraska, were all achieved, with its vaccine demonstrating high efficacy.

 

The vaccine offers protection earlier in the chickens' lives and both the egg injection method and the single dose offers significant levels of protection.

 

As most US poultry broiler hatcheries already own and operate egg injection machines, the ease of administering the egg-injected vaccines is a major commercial advantage, the company said.

 

Imugene is developing two vaccines - one for broiler birds and the other for breeding and egg layer birds.

 

Broiler vaccines are short term since they reach market weight in about six weeks, whereas layers and breeder birds require longer immunity.

 

The vaccine designed for layers and breeders uses two antigens, rather than the single antigen used in the broiler vaccine.