A new study found that antibodies in the animals' blood are effective at preventing many different strains of flu in mice. But the research still has to be replicated in humans. 

By Amanda MacMillan
November 07, 2018

You may have seen some stories in the news recently about how llamas are going to save us all from the flu–and immediately pictured the fuzzy, hooved creatures dressed in lab coats dolling out flu shots to human patients (or wait, is that just me?).

What really happened, according to a study published this week in Science, is that scientists developed a nasal spray derived from llama antibodies, which seem to guard against influenza more effectively than our own human antibodies can.

Next, they gave that nasal spray to mice, and then infected the mice with lethal strains of the flu. All of the mice that had gotten high doses of the spray survived, while those that received a placebo all died. In reviewing the research, one virologist told the BBC that this discovery could be the “Holy Grail” of influenza prevention.

But before you start looking for this llama-inspired miracle drug on pharmacy shelves, there are a few things we should get straight. Here’s a closer look at the science behind the headlines, and what it really means for this flu season.

RELATED: Does the Flu Shot Lose Effectiveness If You Get It Every Year?

What are antibodies?

The key to this new discovery is antibodies. These are proteins produced by the body when the immune system recognizes something foreign, like a bacteria or virus, in the blood.

It’s the antibodies’ job to counteract, or neutralize, that foreign object, which prevents the host from becoming sick. That’s how vaccines work: They cause the body to build up antibodies to a specific virus or bacterium, which hopefully provide immunity when a person is exposed to that pathogen weeks, months, or even years later.

Why are llamas so important?

Human antibodies are relatively large and Y-shaped, and they target a part of the influenza virus that tends to change rapidly as it mutates into different strains. That’s one reason our existing flu vaccines don’t work that well, Popular Science reports: As the virus mutates, it becomes less recognizable to our antibodies.

But the antibodies produced by llamas—and their relatives like camels and alpacas—are different. They’re smaller and straighter, and can target parts of viruses that human antibodies physically can’t reach. (For this reason, llama antibodies have shown promise in other areas of research, as well.)

For this study, researchers gave llamas a flu vaccine and then extracted four different antibodies produced in their blood—two that targeted influenza A and two that targeted influenza B. Then they “tethered” those four proteins together to make a kind of super-antibody, which test-tube studies showed were effective at preventing 60 different flu strains.

"These multi-specific antibodies were able to broadly protect against influenza A and B viruses," Ian Wilson, a structural biologist at the Scripps Research Institute in San Diego and co-author of the new study, tells Health.

RELATED: 25 Ways to Survive Cold and Flu Season

If it works in mice, will it work in humans?

"The next step was to deliver them," Wilson says. He and his colleagues adapted their super-antibodies into a nasal spray and an IV infusion and administered one or the other to old mice with compromised immune systems. (They used a nasal spray rather than a traditional flu shot in order to specifically target the upper airways, where the flu virus tends to strike.) 

The treatments worked: Mice who got the spray or the infusion survived, while those that didn't died. But that doesn’t mean it will definitely work in humans, too.

Studies like this are often tested on mice or other animals before they reach the level of human clinical trials, for reasons that are both practical and safety-related. If a treatment appears successful in animals, human trials are often the next step—but months or even years (and lots of financial and regulatory issues) can separate the two.

There have also been lots of examples of treatments that work in mice but not in humans. In this case, the New York Times points out, it’s possible that the human immune system will recognize the llama antibodies as foreign substances, and develop its own antibodies against them. If that happens, “they might attack, causing a potentially dangerous reaction.”

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So what does this all mean for us?

Any real-life implications from this study are likely years off, and Wilson says that "it remains too early to assess the future potential" of this strategy. But he and his colleagues are still excited about the possibilities.

In their paper, the researchers wrote that—if their findings are replicated in humans—a nasal-spray "vaccine" derived from llama antibodies could likely be effective for years, as opposed to our current seasonal vaccine that must be repeated every year. It could also protect against both seasonal flu and dangerous strains like bird flu.

A nasal spray like this could be “of particular benefit to the elderly and other high-risk groups," they added. And because the nasal spray appears to provide protection almost immediately (as opposed to the flu shot, which takes a few days or weeks), it could potentially be a life-saving tool in the event of a quickly spreading flu pandemic.

Flu experts are hopeful that this study will spark further research—and sooner rather than later, given the staggering death toll of recent flu seasons. “I hope it doesn’t take them 10 years to push it forward,” Kevin Hollevoet, a bioengineer at Leuven University in Belgium, told the Times.

Until then, experts say, get your flu shot and get it every year: For now, it’s the best protection we have against catching the flu, developing serious complications, and passing it on to others.
