Biden administration officials said Wednesday they currently have no plans to approve a stockpiled bird flu vaccine, despite an escalating outbreak among livestock in the U.S. and at least 58 human infections in seven states.
The move means that any decisions about a bird flu vaccine will likely be left to health officials in the new Trump administration, which may be led by anti-vaccine activist Robert F. Kennedy Jr., whom Trump picked to head the Department of Health and Human Services. to lead. Human services.
The virus has been spreading among dairy cows since the spring and had infected at least 774 herds in 16 states as of Wednesday, according to the Centers for Disease Control and Prevention. Last Friday, the Department of Agriculture stepped up its response to the outbreak, issuing a federal order mandating testing of the nation’s milk supply.
The USDA said the testing, which will begin next week in six states, will give farmworkers more confidence in the safety of their animals and their ability to protect themselves from infection, and give officials a better idea of where herds are infected.
The spread of the virus among mammals that have close contact with humans is concerning to public health experts because it gives bird flu many opportunities to jump to humans and possibly mutate to spread effectively from person to person .
Nearly all cases of bird flu in the U.S. have occurred in farm workers who have had contact with infected animals — dairy cows or poultry — apart from one patient in Missouri and a child in California. A teenager in Canada who became very ill and was hospitalized also had no apparent contact with infected animals.
The federal government has two bird flu vaccine candidates available in limited quantities in the country’s Strategic National Stockpile, although they must be approved by the Food and Drug Administration before they can be used.
In May, health officials said the government would explore vaccination if the virus mutated in a way that would make existing antiviral drugs such as Tamiflu less effective, or if it was found to cause serious illness in people.
Dr. Nirav Shah, the CDC’s chief deputy director, said Wednesday that the criteria for deploying a vaccine remains the same.
“When we think about respiratory vaccines, their benefit is in preventing serious diseases and deaths,” Shah said. “If we look at what’s happening right now with H5, even in humans, what we’ve seen so far, fortunately, is mild disease,” he said, using an abbreviation for the strain of influenza virus that caused the bird flu outbreak .
“That’s not a guarantee, and that could change, but that’s one of the things we’re looking forward to because the vaccine would be maximally effective at reducing the severity of the disease,” Shah said. While the government is not currently considering a vaccine, that could change if the outbreak changes, he said.
Still, some public health experts believe now is the time for vaccination, especially for farmworkers.
“I don’t think we should gamble with the lives of farmworkers by waiting until they are hospitalized or die before using the tools we have to protect them,” Jennifer Nuzzo, director of the Pandemic Center, told the Brown University School of Public Health.
A balancing act
Approving or deploying a vaccine is an ongoing balancing act for public health agencies, Shah said, noting that even the safest vaccine can have side effects.
In 1976, at the first signs of an outbreak of H1N1 swine flu in the US, public health officials quickly launched a nationwide vaccination campaign. However, the shot caused a small increased risk of Guillain-Barre syndrome, a rare condition that causes the immune system to attack healthy nerve cells.
The outbreak never spread widely, but it set back public confidence in the flu by decades.
“It led to an analysis and introspection about whether the response to those 13 cases of swine flu had been an overreaction,” Shah said. “And there was indeed a high degree of vaccine skepticism.”
Still, public health authorities are willing to approve a bird flu vaccine if necessary, Shah said, adding that officials consistently test strains against the vaccine candidates.
A spokesperson for the Administration for Strategic Preparedness and Response, an agency within HHS that manages the Strategic National Stockpile, said the agency has been working to “fill and finish” vaccine doses of a vaccine candidate that is well matched to the virus that circulates in dairy cows. .
Up to 10 million doses will be available by the end of the first quarter of next year, enough to vaccinate 5 million people, the spokesperson said.
An FDA spokesperson said the agency is “actively engaged with U.S. federal partners, as well as industry,” including evaluating potential vaccine candidates, should the need arise for use in humans.
When is the right time?
Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, said there is no need to approve a vaccine at this time given the lack of evidence of human-to-human spread nor signs of it indicate that the virus causes serious diseases. disease in humans. Existing tools, such as antivirals and personal protective equipment, are sufficient at this time, he said.
There are a higher number of cases, but Schaffner attributed this to public health officials looking harder for the virus through testing and surveillance.
Schaffner said the new Trump administration’s anti-vaccine rhetoric does not change his position.
“I think we have to be very careful in anticipating what the new administration is going to do,” he said. “The administration is going to get a lot of good, solid scientific evidence, not just from people at the CDC and the Food and Drug Administration, but they’re also going to hear from industry and many public health officials and experts across the country.”
Trump’s transition team did not respond to a request for comment.
Dr. Keith Poulsen, director of the Wisconsin Veterinary Diagnostic Laboratory, also said there is no need to approve a vaccine at this time.
“We must continue to advocate based on the science and data to make informed decisions, or do the best we can at the intersection of science, economics and political science,” Poulsen said.
Nuzzo of the Brown University School of Public Health said that while antivirals are important for anyone exposed to or infected with the virus, their effectiveness is limited by a very narrow window in which they must be administered. She also said the country’s testing strategy is not current enough to adequately protect farmworkers.
A vaccine, she said, could protect farmworkers from the possibility of serious illness.
Poulsen said one problem officials may face is finding farmworkers willing to get the vaccine, noting some may be leery of the shot.
“I would start with seasonal flu and only move to the H5N1 strains if they find that people are spreading the virus or becoming seriously ill,” Poulsen said. “That didn’t happen.”
This article was originally published on NBCNews.com
