So far, the United States has avoided vaccination as a strategy to eradicate avian flu in poultry, instead of depending on infected flocks. With the increase in outbreak by increasing egg prices to record maximum, could that approach change soon?
And as millions of herds continue to die, why don’t vaccines occur?
The Department of Agriculture gave Friday that the federal government could be changing its strategy. The agency said it granted a conditional license for a H5N2 avian flu vaccine designed to work against the H5N1 virus variants, the tension that circulates between the herds of dairy cows and domestic birds in the US. UU. H5N2 belongs to a family of avian flu virus that includes H5N1.
The zoetis license, a vaccine manufacturer based in New Jersey, is a recognition that the vaccine has met the USDA requirements for safety and “reasonable expectation” of effectiveness, said a company spokesman.
However, the USDA has stopped in allowing the doses to be widely distributed. A spokesman for the agency said in a statement sent by email that the conditional license does not mean that he has approved the vaccine for commercial use or that Corral bird farmers can buy it at this time.
“This is simply a normal step in the research and development phase, not in the implementation of a vaccine strategy,” said the USDA spokesman.
Even so, experts say, the measure suggests that federal health officials can be considering other tools, as a vaccine, to address the crisis in progress. In December, the government extended the nation’s milk supply evidence.
Until Tuesday, more than 160 million chicken, turkey, goose and other infected birds have been sacrificed, according to the centers for disease control and prevention. There have been shoots in at least 972 dairy herds in 16 states, although sacrificing cattle is not a typical practice, since they can recover from the disease.
The Secretary of Agriculture Brooke Rollins is expected to “announce a new strategy to combat the virus, a USDA spokesman said without commenting if vaccines would play a role.
If the Federal Government vaccinated Corral’s birds, it could come with a series of complications, in particular that many US commercial partners will not accept exports from countries that allow vaccines, said Carol Cardona, an avian health expert at the University of Minnesota.
“When we talk about poultry, we are talking about ducks, turkeys and chickens, and those are the chickens that we eat and chickens that put eggs, and all are grouped in terms of commercial restrictions,” he said.
The fattening industry, the agricultural sector responsible for raising chicken specifically for meat consumption, would probably be the most affected, said Cardona. It represents about 96% of the poultry industry, he said, and has huge export markets. The stories industry provides $ 449.5 billion in economic activity and $ 36.7 billion in government revenues, according to a report by the Association of Populies and Eggs from the USA, a commercial group of the industry.
“The fattening industry, in their own interest, would say: ‘No, there is no vaccine until there are no layers of eggs,” Cardona said. “It’s an extreme position, but they could.”
In addition, the federal government and manufacturers will still need to make enough vaccines to immunize poultry used. In January, the USDA said it would begin to rebuild its reserve of vaccines against avian flu for poultry.
“So, if the announcement comes, we are ready to vaccinate, people have to make orders,” he said.
Daniel Pérez, an expert in poultry medicine at the Faculty of Veterinary Medicine of the University of Georgia who studies how influenza viruses jump from animals to humans, told that he is concerned that vaccine poultry can facilitate silent propagation , where transmission in asymptomatic birds occurs.
“Vaccines can sometimes be seen as a kind of double -edged sword,” Pérez said. “They can control the disease, but at the same time, they may not be able to control infections. Therefore, vaccinated animals may not show signs of the disease. ”
As you can see with vaccinated humans, not all vaccinated birds will be protected or will have the same level of protection as the next, he said.
“If a high route virus enters an installation of vaccinated chickens, there could be these low levels of viral replication that eventually promotes the appearance of strains with mutations,” said Pérez, “and the effect of those mutations could be a virus with virus with Increased guest range, a virus that can infect other species, “including humans.
Cardona said it is “theoretical”, but that it is possible that there can be vaccinated birds with “silent infections.”
However, he pointed out that the country has many more resources to administer a scenario like that before.
“We have many more laboratories and much more proof capacity than we had when they were theorized to be problems,” said Cardona.
Another consideration is that people who vaccinate birds, probably agricultural workers, will probably need adequate protection to ensure that the virus is not infected, said Dr. William Schaffner, an expert in infectious diseases at the University Center of the University of the University of the University of the University From Vanderbilt in Nashville, Tennessee.
Public health experts said, have been concerned about the potential risks for the health of corral birds and dairy workers who work very close to animals and, often, in dirty environments.
Pérez said that there is currently an ongoing investigation to provide mass vaccination of poultry through drinking water, reducing human exposure.
Another idea is to vaccinate agricultural workers against the virus, Schaffner said.
“Dangerous costumes and shields and gloves, things that work quite well in the hospital when you take care of a patient, do not work so well when you are on the farm,” he said.
Pérez said that influenza vaccines for poultry and humans are not highly effective, and generally use an older technology that takes months to produce doses.
“I would say that we should use this crisis as an incentive to investigate more about the improvement of vaccines,” he said.
