The United States has vaccines against bird flu. Here’s Why You Can’t Get One

Like bird flu rages among birds and dairy cattle across the United States, Georgia became the latest state to detect the virus in a commercial poultry flock, and on Friday it halted all poultry sales to mitigate the spread of the disease. Nationally, egg prices are skyrocketing, if you can find them at your local grocery store.

The ongoing outbreak in animals has also led to at least 67 human cases of avian flu, with all but one causing mild illness. Earlier this month, a person in Louisiana died after being hospitalized with severe bird flu in December. This is the first death recorded in the country attributed to H5N1.

The United States has already authorized three H5N1 vaccines for humans, but they are not commercially available. The government has purchased millions of doses for the national stockpile in case they are needed. But even as the outbreak spread, federal health officials under President Joe Biden were reluctant to deploy them. Experts say the decision depends on risk and currently the risk of contracting the H5N1 virus remains low. Deploying a vaccine to farmworkers and others at higher risk of infection would be a more targeted tactic, but even that move could be premature. Now, with a change in federal leadership on health care looming as President Donald Trump begins his second term, the decision rests with the new administration.

“At the moment, from the perspective of severity and ease of transmission, it does not seem imperative to develop a vaccine to protect humans,” says William Schaffner, a physician and professor of preventive medicine at the university. Vanderbilt of Tennessee. .

So far, no human-to-human spread of H5N1 has been identified, but health authorities are monitoring the virus for any genetic changes that would make transmission between humans more likely. Most avian flu infections are linked to animal exposures. Of the 67 known human cases in the United States, 40 have been linked to sick dairy cattle and 23 are associated with poultry farms and slaughter operations. In the other four cases, the exact source is not known.

In the United States, human cases have been mild, with most causing only conjunctivitis. In some cases, people experienced mild respiratory symptoms. With the exception of the Louisiana patient, everyone who tested positive for H5N1 recovered quickly and never required hospitalization. However, historically, H5N1 has been fatal in about 50 percent of cases. Since 2003, a total of 954 human cases of H5N1 have been reported to the World Health Organization, and about half of them have died. Egypt, Indonesia, Vietnam, Cambodia and China have reported the highest number of human deaths from bird flu.

These numbers come with a few caveats. For one thing, many of these deaths have occurred in places where people live very close to sick poultry. “Under these circumstances, we think they probably received a very high dose of the virus,” says Schaffner.

Additionally, the case fatality rate – the proportion of infected people who die from the disease – only takes into account known cases, and some cases of H5N1 may go unnoticed, in part because the symptoms of bird flu are similar. to those of other respiratory viruses. In the United States, language barriers among farmworkers, lack of testing and workers’ reluctance to report sick are also factors to consider. “We’re probably missing more cases than we’re detecting, and we’re much more likely to detect a severe case,” says Shira Doron, chief of infection control at Tufts Medicine in Boston and a hospital epidemiologist at Tufts Medical Center.