Along with feeling eyes, a long, warm neck, the llamas coat has a feature that is underappreciated: they make the immune system's antibody arrangement so small that it can enter into the cracks on the surface of the invading virus.
That achievement can one day protect humans from the whole family of flu viruses that make it difficult for scientists to deform and unpredictable.
All, potentially, once a year puffs up the nose.
In a study published in the journal Science, a team from the Scripps Research Institute in La Jolla, California, United States, and their international partners have taken a big step towards a long-term goal of developing a universal vaccine against influenza.
When they tested their intranasal formulations in mice, it quickly provided complete protection against rafts of human flu strains adapted to mice.
They include the A virus, such as H1N1 "swine flu" which touched the global pandemic in 2009, and virus B, which only occurs in humans.
Against H1N1, the dose of the experimental vaccine has been shown to protect for at least 35 days – a timeframe that is equivalent to more than one single flu season for humans.
Dr. Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases (NIAID), offers full awards for new studies, which receive funding from the US National Health Institute.
"From a scientific and technical point of view, this is truly a very elegant study – the highest quality of science," he said.
He praised it because it showed that to protect people from pathogens that could change or emerge unexpectedly, scientists had to build vaccines that could knock down various viruses, even in people whose immune systems were fragile or disturbed.
Influenza is a viral scourge that kills as many as 650,000 people every year, according to the World Health Organization.
To counter it, the research team borrowed new techniques from immunology, microbiology, nanotechnology and genetic engineering laboratories throughout the world.
First, they vaccinate llamas against a number of A and B influenza strains. Then they took blood samples to collect antibodies produced by llamas in response.
Among them there are four unique small antibodies that show the ability to destroy various types of influenza. In nodding to their size and function, they called their creation "nanobodies".
Of those who have a lot of small strength, the researchers engineered a protein that is able to squeeze into space on the surface of the virus that is too small for most proteins.
"Multidomain antibodies MD3606" produced, with "impressive strength and potential", can provide protection against almost all types of flu that nature can cause in a human way, the study authors said.
If the dominant strain in a particular season suddenly changes, these antibodies will be ready for unwanted guests.
If the flu strain comes out of nowhere and threatens the population without immunity to it – the flu pandemic nightmare scenario – this supercharged defender will recognize the flu and fight it.
If health officials guess wrong about what flu strain comes and order a vaccine that is largely ineffective – the scenario that occurs in the 2017 flu season – this package of antibodies can save the day.
But researchers still face major obstacles: getting the human immune system to make super proteins like that even when it's burdened by age, stress and disease.
Their solution: Don't try.
Instead, they found a way to overcome an unreliable human response to vaccines, building genes that encode production plans for their power generation proteins.
To transport the gene into the host organism, they register a harmless virus used by laboratories working on gene therapy.
By combining their designer genes into this viral delivery device, scientists not only found a way to get their antibody packages to host, but they also gave manufacturing machines to produce them.
"Passive transfer" of these antibodies gives potential vaccines the potential to be as effective in everyone, said Dr Fauci.
The next step is to conduct further tests on animals and clinical trials in humans, and that "will take years", he said.
"But if it really works – a tremendous leap now – basically eliminates season-to-season needs" for which of the many flu viruses might be raised, and to later build an annual flu vaccine that neatly fits the bill.
Immune script expert Dr Ian Wilson, the study's senior author, said that when cells are "infected" by a back-shipping virus, repeated doses may be needed to maintain antibody production. "We don't really know how long this treatment will last in humans," he said.
But even less permanent immunity to various flu threats will help support people from the emergence of unexpected flu strains, he said.
And the rat's rapid response to the vaccine shows that it can be used to inject a population after a new virus threat appears, he added.
That experimental vaccines might need to be given each year makes it an attractive hybrid, said Dr. Ted M. Ross, who heads the University of Georgia's Vaccine and Immunology Center.
"This approach is similar to antivenom," he said. "Therapy is an antibody made in other species to neutralize poisons. This is short term, but it makes you go through a period of time where bad things can happen. "
Over time, patients who get the same antibodies may repeatedly start building resistance to them, he said.
Vaccine makers can fight that by finding and entering new antibodies in their formulations every few years, he suggested.
Dr. Ross and other scientists also warned that the human immune system might see proteins derived from llamas as foreign matter and attack them.
This is not the only universal flu vaccine that is being developed. In May 2018, NIAID launched the first clinical trial to test the safety of the universal flu vaccine in 120 healthy humans.
The candidate vaccine, called M-001, targets parts of the flu virus that tend not to change even like other proteins. This should prioritize the human immune system to recognize and fight many different types of influenza viruses.
Janssen Vaccine and Prevention, a Dutch company that employs several research writers, has submitted a patent application that will cover some of the molecules described in the report. – Los Angeles Times / Tribune News Service