US focused on limiting spread amid record bird flu season, but vaccines could be a possibility in the future


The Biden administration is monitoring what experts say is the deadliest bird flu outbreak the United States has ever seen, and officials are considering a “range of options” for how to respond.

The outbreak is currently not considered a serious threat to human health, according to the US Centers for Disease Control and Prevention.

Globally, there have been only a handful of cases of bird flu in humans, mostly in people who have had direct contact with infected birds or with surfaces contaminated with their excretions. There was one human case last year in the United States, a Colorado man who fell ill after shooting infected birds. He was isolated and treated with an antiviral.

More than 860 total cases of bird flu have been reported in humans in 19 countries since 2003, and more than half of those cases have been fatal, according to the CDC.

World Health Organization Director-General Tedros Adhanom Ghebreyesus said in February the risk to humans was still low. But given the large number of infected birds, he added, “we cannot assume that will remain the case”.

According to the CDC, there have been 6,356 cases in wild birds in all 50 states, but there are likely many more. In 47 states, there have been multiple outbreaks in poultry, involving more than 58.6 million birds. It has also appeared in non-commercial backyard flocks, according to the US Department of Agriculture.

The disease has also shown up in other animals in the United States, including bears, foxes, raccoons, opossums, cougars, bobcats and even a bottlenose dolphin. As the virus moves through mammals, the chances increase that it can mutate and spread more easily among humans.

The CDC is able to monitor the virus in communities through the labs it uses to monitor more typical influenza viruses. The agency also told CNN it is also investigating whether manufacturers might want to do commercial testing for these viruses. more widely available.

The Biden administration has said it is also monitoring the situation carefully.

“As part of the administration’s emphasis on fighting any infectious disease with urgency and preparedness, we continue to monitor the avian flu outbreak. There are a range of options that the United States routinely considers in the event of an outbreak that could affect the security and safety of the United States food supply,” a National Security Council official told CNN.

“Right now, we are focused on promoting and improving high-impact biosecurity practices and procedures.”

Biosecurity procedures generally include enhanced disinfection practices for people working with birds. In November, the CDC recommended that people who interact with birds that appear sick — even in backyard flocks — wear disposable gloves, boots, goggles, and an N95 respirator or face mask.

“The CDC continues to take any infectious disease threat seriously and rates the current risk of avian influenza to humans as very low. The Department of Agriculture continues to respond quickly whenever the virus is detected among bird populations,” the National Security Council official said.

The CDC says the risk assessment tool it uses to understand a virus’s potential as a pandemic risk determined that if these H5N1 viruses were to mutate into a version that could easily and efficiently spread to In humans, the risk of a pandemic is “moderate” and the public health impact of such an event would also be of moderate severity.

“That’s why it’s so important that public health and animal health take precautions to limit exposures between animal species and between animals and humans, and thus limit the chances that a certain type of reassortment of viruses that can allow these viruses to infect people easily and spread easily between people,” the agency said in an email to CNN.

General precautions include controlling animal outbreaks and limiting public exposure. This includes avoiding close contact with sick birds, cooking poultry thoroughly, and not eating raw eggs.

Another precaution is to take steps for a vaccine, just in case, and efforts are underway.

Scott Hensley, professor of microbiology at the University of Pennsylvania, and his colleagues have been working on a candidate vaccine that could be used in humans if the virus starts circulating among humans.

“We think the vaccine will elicit very high levels of neutralizing antibodies against this specific strain because it’s basically a perfect match for what’s circulating now,” Hensley said.

The vaccine appears to work well in the lab, he said, and researchers plan to test it in chickens this spring.

The CDC says it recently produced a candidate vaccine virus, an influenza virus that manufacturers can use to make a vaccine, which is nearly identical to a viral protein detected in birds and mammals. It could be used to produce a vaccine for people “if needed”.

“Such a vaccine should provide good protection against circulating H5N1 viruses,” the CDC said. The agency said it shared this with vaccine makers.

For years, the Southeast Poultry Research Laboratory, a division of the United States Department of Agriculture, has also been working on a vaccine for potential emergency use in animals. There may be an advantage to vaccinating poultry to reduce the chances of the virus mutating.

Vaccinating poultry against bird flu, “isn’t something that’s really done in our country, but I think it’s time to think about it for sure,” Hensley said.

Farm animals, including birds, are already vaccinated against other diseases. Chickens, for example, are regularly vaccinated against Marek’s disease, caused by a herpes virus. They are also vaccinated against Newcastle disease, a respiratory illness; infectious bronchitis; and acute necrotic proventriculitis, a viral disease that affects the immune system.

Avian flu may one day be included in this list, according to a USDA spokesperson.

“In the interest of sparing no effort in the fight against (highly pathogenic avian influenza), the USDA continues to research vaccine options that can protect poultry from this persistent threat,” the spokesperson told CNN.

Vaccination, however, is not the first option.

“From vaccine development to production timelines to herd release, many factors make implementing a vaccine strategy a challenge, and it would take time to deliver an effective vaccine,” said the President. USDA.

So, above all, “we continue our efforts to work with poultry farmers and companies on education, training and implementing comprehensive biosecurity measures. Biosecurity is the best and most precautionary approach we have to mitigate the impact of disease today. »

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