Inside the Worldwide Influenza Centre: monitoring the constant threat of flu and other viruses

The threat of influenza—and other viruses

As many as 650 000 people worldwide die of respiratory diseases linked to seasonal flu.2 The world faced three major global flu pandemics in the 20th century, and the 2009 H1N1 swine flu pandemic is thought to have claimed as many as a quarter of a million lives.3

“If collaborating partners in countries around the world detect an animal influenza virus that has infected a human, they share the material with us and we analyse it,” says Lewis. “We have been inherently involved in not only avian influenza viruses but also swine influenza viruses which are periodically detected in the human population. All these viruses in animals continue to pose a significant zoonotic threat.”

Lewis and her team look at the properties of the viruses, including what immune response they trigger and how they compare with the list of candidate vaccine viruses that have already been recommended for pre-pandemic preparedness.

She says, “If there are significant differences from candidate vaccine viruses we’ve already recommended, sometimes there’s a move to update a recommendation and make a new recommendation for particular viruses that are potentially risky.”

On top of this they analyse the genomes of the viruses to look for potential markers that could suggest that the viruses are changing and, with that, the risk they pose. “This is a tricky thing to do,” says Lewis. “Often the changes are associated with a particular kind of virus, and although they might have been understood experimentally in one particular virus, we can’t always be sure that the same mutations are going to have the same effect in viruses that have continued to evolve and continue to evolve in animal populations.”

Earlier this year Jeremy Farrar, WHO’s incoming chief scientist, told The BMJ that governments should be investing in vaccines for every single strain of influenza that exists in the animal kingdom, through at least phase 1 and 2 studies.4

Lewis agrees. For her, without at least some level of action the candidate vaccine virus list—which takes up a lot of time and resources every year—“just stays as a wish list, it has no utility . . . this gets us no further up the tracks towards pandemic preparedness.” There are many unanswered primary questions on issues such as whether vaccine candidates could provide cross protection against a variety of circulating clades or strains.

And assessing even just every single influenza virus would be a challenge. “It’s an enormous undertaking,” Lewis admits. “But, if we don’t do it, we don’t have the information to make informed decisions about what we do for pandemic preparedness.”

“Inevitable” future pandemics

For Lewis, another pandemic is not a matter of if but of when. “We face a constant threat from emerging infectious diseases,” she says. “I certainly think that, I’m afraid to say, future pandemics are likely inevitable.”

With that in mind, assessing what happened during the covid-19 pandemic is vital. “We really need to take a long, hard look at what we can learn from the covid pandemic and the response to it,” she says. Her hope is that those learnings, as well as what we can take from the Global Influenza Surveillance and Response System over the past 70 years, could mean that the next time we face a pandemic we don’t have to face the worst effects.

But she’s not entirely hopeful, especially when it comes to research and diagnostics. “If you look at emerging infectious diseases, one of the initial things you need are sensitive diagnostics,” she says. “Some of the initial challenges in the first few weeks and months of the covid pandemic could do a lot to illuminate what we need to do in the next pandemic. I’m not completely convinced that we have remembered those challenges and that we’re thinking about how to do it better in the future.”

She shares the concerns of many researchers who believe that, by cutting back rather than boosting the research networks and surveillance system built during the covid pandemic, we’re missing a huge opportunity to progress our preparedness.

“We’re at a critical juncture here where we frankly can’t afford to stop the process,” says Lewis. “We cannot not take this opportunity to learn what we can from the covid pandemic, to make sure that we’re better prepared next time. Because there will be a next time, and I’m very concerned that a short term retraction of funding will essentially stop the process.”

She concludes, “There’s an awful lot of diversity out in the animal population in terms of influenza, whether it’s in the bird population or whether it’s in the swine population. And any one of those viruses could start the next pandemic.”