Imagine a single dose of vaccine that prepares your body to fight every known strain of influenza — a so-called universal flu vaccine that scientists have been trying to create for decades.
A new study describes successful animal tests of just such a vaccine, offering hope that the country can be protected against future flu pandemics. Like the Covid vaccines made by Pfizer-BioNTech and Moderna, the experimental flu vaccine relies on mRNA.
It is in early stages — tested only in mice and ferrets — but the vaccine provides important proof that a single shot could be used against an entire family of viruses. If the vaccine succeeds in people, the approach could be used against other virus families, perhaps including the coronavirus.
The vaccine would not replace annual flu shots but would provide a shield against severe disease and death from potential pandemic threats.
“There’s a real need for new influenza vaccines to provide protection against pandemic threats that are out there,” said Scott Hensley, an immunologist at the University of Pennsylvania who led the work.
“If there’s a new influenza pandemic tomorrow, if we had a vaccine like this that was widely employed before that pandemic, we might not have to shut everything down,” he said. He and his colleagues described the vaccine last week in the journal Science.
By the age of 5, most children have been infected with the flu multiple times and have gained some immunity — but only against the strains they have encountered.
“Our childhood exposures to influenza lay down long-lived immune memory that can be recalled later in life,” Dr. Hensley. But “we’re sort of living the rest of our life dependent on the random chance of whatever we got infected with as a kid.”
Current influenza vaccines protect against seasonal flu but would provide little protection against a new strain that may emerge as a pandemic threat. During the 2009 H1N1 swine flu pandemic, for example, the conventional vaccine offered little defense against the virus. But older adults who had been exposed to H1N1 strains in childhood developed only mild symptoms.
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