this is KFF Health News Article.
As bird flu spreads among dairy cows in the United States, veterinarians and researchers are looking to Finland for help vaccinating at-risk farm workers and wondering why their own government isn’t doing the same.
“Farm workers, veterinarians and producers are handling large volumes of milk that may contain high concentrations of avian influenza virus,” says Kay Russo, a livestock and poultry veterinarian in Fort Collins, Colo. “If the vaccine is going to confer some immunity, I think it should be offered to them.”
Most of the 12 virology and infectious disease experts interviewed by KFF Health News agreed with Russo. They said people who work with dairy cows should be encouraged to vaccinate against the disease, which has killed about half of the people known to have been infected worldwide in the past 20 years, killed a cat in the U.S. this year, and has pandemic potential.
But some researchers agree with the Centers for Disease Control and Prevention (CDC), which recommends against vaccination for now: There is no evidence that this year’s avian flu virus can be transmitted from person to person or cause severe illness in people, and it’s unclear how well currently available vaccines can prevent either scenario.
But a wait-and-see approach is “a gamble,” says Jennifer Nuzzo, director of the Brown University Pandemic Center: “By the time we see severe outcomes, a lot of people will already be infected.”
“Now is the time to get the vaccine to American farmworkers,” said Nahid Bhadelia, director of the Center for Emerging Infectious Diseases at Boston University, adding that the U.S. is overdue for more urgent action. Testing of farmworkers and cattle is desperately needed to detect, study and eradicate the H5N1 avian influenza virus before it takes hold on farms and becomes a constant pandemic threat.
Demetre Daskalakis, director of the CDC’s National Center for Immunization and Respiratory Diseases, said the center takes avian flu seriously and the U.S. is stockpiling the vaccine. 4.8 million doses On vaccines, however, he said, “we are not recommending that a vaccination campaign be launched.”
“It’s all about the risk/benefit ratio,” Daskalakis said. The benefits are unclear because Not tested enough The aim is to understand how easily the virus can jump from cows to humans and how severe it can cause. Only four people in the US have tested positive for the disease this year, and all of them had mild symptoms — too few to draw any conclusions.
Other farmworkers and veterinarians at the affected dairy have also reported feeling sick but have not been tested, Russo said, and the public health lab has only tested about 50 people for avian flu since the outbreak was confirmed in March.
Still, Daskalakis said the CDC isn’t worried that its flu surveillance system is missing worrisome bird flu cases: Hospitals are reporting severe flu cases, and the number of cases this year is normal.
Another sign that officials can take comfort in is that the virus has not yet mutated in a way that would allow it to spread rapidly from person to person through sneezing or breathing. “If we start to see changes in the virus, that will be part of the decision to move from the planning phase to the operational phase,” Daskalakis said.
July 8th, The researchers reported The virus may be more likely to spread from person to person than previously thought: While it doesn’t appear to be contagious yet, experiments suggest it is capable of infecting the human respiratory tract, and it has also been shown to spread through the air between two laboratory ferrets.
In considering a vaccine, the agency took inspiration from the swine flu epidemic of 1976. Officials initially feared a repeat of the 1918 swine flu pandemic, which killed about 500,000 people in the U.S. So they rushed to vaccinate the nation’s roughly 43 million people within a year.
However, cases of swine flu that year turned out to be mild, which led to several reports of the potentially fatal disease Guillain-Barré syndrome, making the vaccine seem unnecessarily dangerous. One in a million According to the CDC, people who get the flu vaccine may still get the flu. The risks outweigh the benefits of prevention. After October 1, 830,000 people Between 25,000 and 75,000 people were hospitalized with seasonal flu and died.
Ann Post-mortem report Daskalakis, who studied the 1976 swine flu situation, called the report a “sobering cautionary tale” about responding prematurely to an uncertain public health threat. “This is the story of what happens when you accept the risks and launch a vaccine program when there is no benefit,” Daskalakis said.
Paul Offit, a virologist at the Children’s Hospital of Philadelphia, sided with the CDC. “We’re going to wait until we have more data,” Offit said.
But other researchers say this isn’t comparable to 1976, because they’re not proposing that the U.S. vaccinate tens of millions of people. Rather, they’re proposing that thousands of people who come into close contact with livestock voluntarily be vaccinated, which would lower the chance of rare side effects.
The avian flu vaccine I have on hand is manufactured by the influenza vaccine company CSL Seqirus. Approved last year It was approved by the European equivalent of the FDA. The older varieties have been approved by the FDA, but the newer varieties have not yet.
The vaccine targets a different strain of bird flu virus to the H5N1 currently circulating in cattle, but studies have shown it generates an immune response against both strains, and because it is the same, it is considered safe. Egg-based vaccines A technology that is introduced annually into seasonal influenza vaccines.
For these reasons, the United States, the United Kingdom, the Netherlands, Approx. 12 pieces Other countries are stockpiling millions of doses of the vaccine. Finland will offer the vaccine to fur farm workers this month as a precautionary measure after mink and fox farms were hit by bird flu last year.
In contrast, an mRNA vaccine being developed against avian influenza would be the first attempt against influenza. On July 2, the US government announced it had paid Moderna $176 million for its development, and that the vaccine could enter clinical trials next year. This new technology, widely used to fight COVID-19, uses mRNA to teach the immune system how to recognize a specific virus.
But Florian Kramer, an influenza virologist at the Icahn School of Medicine at Mount Sinai, said dairy workers should be given the option of an egg-based vaccine, which he said would induce an immune response to the main component of the H5N1 avian flu virus and provide some protection against infection and severe disease.
Still, vaccines aren’t 100% effective, and because they haven’t been used to combat the virus this year, no one knows how many cases and hospitalizations the vaccines will prevent. That data should be collected in studies tracking outcomes for people who choose to get vaccinated, he said.
Kramer isn’t satisfied that no serious cases of bird flu have been found at the clinic. “If we see signs in the hospital, we’re out of control. Game over. It’s a pandemic,” he said. “We want to avoid that.”
He and other researchers stressed that the U.S. should do all it can to contain infections before flu season begins in October. A vaccine could provide an extra layer of defense, in addition to testing, wearing gloves and goggles, and sanitizing milking equipment. Scientists worry that simultaneous infection with avian and seasonal influenza could allow the avian flu virus to adapt from the seasonal virus and spread rapidly among humans.
“The vaccine is a very important tool to help prevent disease and improve the lives of people who work with dairy cows,” said Bethany Boggess Al-Kawter, director of research at the National Farmworker Health Center, which is a nonprofit organization.
Health officials have spoken to dairy owners, but those conversations don’t appear to have trickled down to farm staff, according to Boggess’ interviews with farm workers. Texas Panhandle Farm workers told her they were instructed to disinfect their hands and boots to protect the cows from any diseases the workers might carry. “We were not told anything about whether the cows could transmit any diseases to us,” the farm worker said in Spanish.
The slow pace of the education effort is a reminder that everything takes time, including vaccine decisions. When deciding whether to recommend a vaccine, the CDC typically turns to the Advisory Committee on Immunization Practices (ACIP). William Schaffner, an infectious disease researcher who advises the committee, has repeatedly asked the CDC to take a position on the Sequilas avian flu vaccine.
Rather than worrying about the 1976 swine flu situation, Schaffner suggested the CDC think about the 2009-2010 swine flu pandemic, which caused more than 274,000 hospitalizations and 12,000 deaths in the U.S. within a year. By the time the vaccine was widely available, most of the damage had already been done, Schaffner said.
“The time to have this conversation with ACIP is now,” Schaffner said before avian flu became a public health emergency, “and I don’t want to have this conversation until the cows come home in the middle of a crisis.”
