Speaker 1: Welcome to brain Stuff, a production of iHeart Radio, Hey
Speaker 1: brain Stuff, Lauren vogelbam here. Your annual flu shot protects
Speaker 1: you from some types of influenza, usually the ones that
Speaker 1: got people sick the year before, but if a new
Speaker 1: strain of flu shows up, the shot may not work
Speaker 1: for it. That's why holy grail of medicine is to
Speaker 1: create a universal flu vaccine, and a universal flu vaccine
Speaker 1: can't come soon enough, especially for particularly vulnerable populations such
Speaker 1: as children, the elderly, and the immune compromised. More than
Speaker 1: six hundred and fifty thousand people around the world die
Speaker 1: of seasonal influenza every year, according to the World Health Organization.
Speaker 1: The seasonal flu also costs the US health care system
Speaker 1: in society in general a lot, about eleven point two
Speaker 1: billion dollars in eighteen alone. Of course, this is to
Speaker 1: say nothing about COVID nineteen, which is caused by a coronavirus,
Speaker 1: which is an hirely different virus than the multiple strains
Speaker 1: of influenza that cause the flu. Although some symptoms of
Speaker 1: both COVID nineteen and the flu can be similar. The
Speaker 1: researchers are racing to develop the first coronavirus vaccine, though
Speaker 1: none have been successful yet. These things take time. But
Speaker 1: we've had vaccines for the flu for years, so why
Speaker 1: haven't we developed a universal flu vaccine that could stop
Speaker 1: all future iterations of the flu. The threat and impact
Speaker 1: are so great that it would surely be worth researchers time.
Speaker 1: It has to do with the fact that influenza is
Speaker 1: incredibly cunning. We talked with Dr Greg Poland, spokesperson for
Speaker 1: the Infectious Diseases Society of America and professor of Medicine
Speaker 1: and Infectious Diseases at the Mayo Clinic in Rochester, Minnesota.
Speaker 1: He noted the trillions of new strains of the flu
Speaker 1: can develop in mere minutes. Quote, you can hardly imagine
Speaker 1: a more promiscuous virus. Fortunately, of new strains don't have
Speaker 1: genetic fitness us they can't survive. However, those that remain
Speaker 1: can pack a pretty serious punch. Those survivors can either
Speaker 1: experience antigenic shift or antigenic drift. Let's break that down.
Speaker 1: In antigenic shift, a gnome strain of the flu morphs
Speaker 1: into a novel strain that can cause a pandemic level
Speaker 1: flu event, such as H one, N one and avian influenza.
Speaker 1: This hardly ever happens. There have been just four influenza
Speaker 1: pandemics in the last hundred years, but when it does,
Speaker 1: it can be dire. The shift that resulted in the
Speaker 1: H one N one influenza pandemic of en sometimes called
Speaker 1: the Spanish flu, infected five hundred million people and killed
Speaker 1: fifty million around the world. This was, of course, before
Speaker 1: antibiotics were available to treat secondary bacterial infections associated with
Speaker 1: the flu. Also, vaccines were not around to prevent infection
Speaker 1: and lesson severity. But back to shift and drift. In
Speaker 1: comparison to rare but dangerous shifts, antigenic drift happens all
Speaker 1: the time with influenza, resulting in many small changes to
Speaker 1: the virus, which makes it tricky for vaccine developers to
Speaker 1: nail even the annual flu virus squarely on the head.
Speaker 1: Poland said, so, what happens is about a quarter of
Speaker 1: a million viruses are isolated every year and genetically sequenced
Speaker 1: to give us an idea of what's circulating. It takes
Speaker 1: six months or so to develop and distribute the flu vaccine.
Speaker 1: By that time, many of the strains have drifted to
Speaker 1: the point where they have next to no protection, meaning
Speaker 1: that one of the reasons you can still get the
Speaker 1: flu after receiving a flu vaccine is that the strain
Speaker 1: you get may have developed after the vaccine was created. Again,
Speaker 1: these things take time, but it's worth noting here that
Speaker 1: even a mismatched vaccine is known to reduce the severity
Speaker 1: of flu symptoms and the length of the overall illness,
Speaker 1: so it's important to get the vaccine annually if you can.
Speaker 1: After all, it's better to be bedridden for three days
Speaker 1: than seven or worse, to end up in the hospital.
Speaker 1: There are multiple roadblocks to developing a universal flu vaccine,
Speaker 1: but a number of biotech companies and academics are currently
Speaker 1: working to overcome them. Poland explained that one idea is
Speaker 1: to develop broadly neutralizing antibodies to influenza viruses that would
Speaker 1: ideally protect against every influenza strain. Let's talk a bit
Speaker 1: about how the influenza virus works. Simply put, the influenza
Speaker 1: virus is made up of a couple types of proteins
Speaker 1: called H proteins and N proteins, plus a stock. Current
Speaker 1: vaccines attempt to teach your immune system how to hit
Speaker 1: the H and N proteins, which are what the virus
Speaker 1: uses to attach to and infect human cells. The problem
Speaker 1: is that the exact makeup of those proteins drifts all
Speaker 1: the time. By comparison, Poland explained, the stock portion is
Speaker 1: relatively invariant. So the very it has been why don't
Speaker 1: we shift how we technologically make flu vaccines to the
Speaker 1: portion of the virus that doesn't shift and drift. Another
Speaker 1: complexity is that flu viruses only infect the outermost cells
Speaker 1: lining the respiratory tract, a part of what's called the
Speaker 1: respiratory mucosa. Flu Viruses do not replicate throughout the body,
Speaker 1: which is known as systemic replication. But we also spoke
Speaker 1: with Dr Jeffrey Taubenberger, a virologist with the National Institute
Speaker 1: of Allergy and Infectious Diseases. He said, if you look
Speaker 1: at vaccines that provide good lifelong immunity, like measles, one
Speaker 1: of the differences there is the kind of recall you
Speaker 1: get from a systemic infection is different and much better.
Speaker 1: There's something we're not understanding about how immunity at the
Speaker 1: mucosal level sets up long term immunity. This kind of
Speaker 1: protective immunity is hard to establish. We have to come
Speaker 1: up with ways to bolster the mucosal immune responses to
Speaker 1: give us better protection with these kinds of vaccine. So,
Speaker 1: in other words, a universal vaccine would again ideally help
Speaker 1: your immune system at the local level where the infection
Speaker 1: actually occurs, but we just don't understand enough about how
Speaker 1: that works in order to help. Once this gets worked out,
Speaker 1: it could prove helpful in the development of universal vaccines
Speaker 1: for other respiratory ailments like coronavirus. With any luck, one
Speaker 1: or more of the numerous universal flu vaccine development efforts
Speaker 1: currently going on will pan out. A version developed by
Speaker 1: the pharmaceutical company Seek is about to enter phase three
Speaker 1: clinical trials, and Dr Taubenberger's own team is hoping to
Speaker 1: start human clinical trials on their vaccine in and don't
Speaker 1: expect a universal flu vaccine to be ready too soon, though,
Speaker 1: as it's an arduous undertaking that requires a lot of
Speaker 1: trials to get FDA approval. It's a multi step process
Speaker 1: that ensures that drugs are safe and effective. Poland explained.
Speaker 1: Typically it takes hen or more years and it costs
Speaker 1: about a billion dollars. We should note that in case
Speaker 1: of emergency, new drugs can and have been brought through
Speaker 1: the process sooner, but it takes again, work and money.
Speaker 1: Today's episode was written by Aliya Hoyt and produced by
Speaker 1: Tyler Clang. For more in this and lots of other topics,
Speaker 1: visit how stuff works dot com. Brain Stuff is production
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