1 00:00:01,920 --> 00:00:06,360 Speaker 1: Welcome to brain Stuff, a production of iHeart Radio, Hey 2 00:00:06,400 --> 00:00:11,039 Speaker 1: brain Stuff, Lauren vogelbam here. Your annual flu shot protects 3 00:00:11,039 --> 00:00:14,200 Speaker 1: you from some types of influenza, usually the ones that 4 00:00:14,240 --> 00:00:17,279 Speaker 1: got people sick the year before, but if a new 5 00:00:17,320 --> 00:00:19,959 Speaker 1: strain of flu shows up, the shot may not work 6 00:00:20,000 --> 00:00:23,319 Speaker 1: for it. That's why holy grail of medicine is to 7 00:00:23,400 --> 00:00:28,600 Speaker 1: create a universal flu vaccine, and a universal flu vaccine 8 00:00:28,640 --> 00:00:33,000 Speaker 1: can't come soon enough, especially for particularly vulnerable populations such 9 00:00:33,040 --> 00:00:37,199 Speaker 1: as children, the elderly, and the immune compromised. More than 10 00:00:37,240 --> 00:00:39,920 Speaker 1: six hundred and fifty thousand people around the world die 11 00:00:40,000 --> 00:00:43,560 Speaker 1: of seasonal influenza every year, according to the World Health Organization. 12 00:00:44,280 --> 00:00:47,320 Speaker 1: The seasonal flu also costs the US health care system 13 00:00:47,360 --> 00:00:51,040 Speaker 1: in society in general a lot, about eleven point two 14 00:00:51,120 --> 00:00:55,720 Speaker 1: billion dollars in eighteen alone. Of course, this is to 15 00:00:55,720 --> 00:00:59,200 Speaker 1: say nothing about COVID nineteen, which is caused by a coronavirus, 16 00:00:59,280 --> 00:01:02,120 Speaker 1: which is an hirely different virus than the multiple strains 17 00:01:02,160 --> 00:01:05,440 Speaker 1: of influenza that cause the flu. Although some symptoms of 18 00:01:05,440 --> 00:01:08,600 Speaker 1: both COVID nineteen and the flu can be similar. The 19 00:01:08,680 --> 00:01:12,120 Speaker 1: researchers are racing to develop the first coronavirus vaccine, though 20 00:01:12,120 --> 00:01:16,880 Speaker 1: none have been successful yet. These things take time. But 21 00:01:17,040 --> 00:01:20,000 Speaker 1: we've had vaccines for the flu for years, so why 22 00:01:20,040 --> 00:01:22,919 Speaker 1: haven't we developed a universal flu vaccine that could stop 23 00:01:23,000 --> 00:01:26,360 Speaker 1: all future iterations of the flu. The threat and impact 24 00:01:26,360 --> 00:01:29,160 Speaker 1: are so great that it would surely be worth researchers time. 25 00:01:30,760 --> 00:01:33,000 Speaker 1: It has to do with the fact that influenza is 26 00:01:33,040 --> 00:01:37,720 Speaker 1: incredibly cunning. We talked with Dr Greg Poland, spokesperson for 27 00:01:37,760 --> 00:01:41,200 Speaker 1: the Infectious Diseases Society of America and professor of Medicine 28 00:01:41,200 --> 00:01:44,920 Speaker 1: and Infectious Diseases at the Mayo Clinic in Rochester, Minnesota. 29 00:01:45,480 --> 00:01:48,080 Speaker 1: He noted the trillions of new strains of the flu 30 00:01:48,160 --> 00:01:52,600 Speaker 1: can develop in mere minutes. Quote, you can hardly imagine 31 00:01:52,640 --> 00:01:59,200 Speaker 1: a more promiscuous virus. Fortunately, of new strains don't have 32 00:01:59,240 --> 00:02:03,880 Speaker 1: genetic fitness us they can't survive. However, those that remain 33 00:02:04,040 --> 00:02:08,079 Speaker 1: can pack a pretty serious punch. Those survivors can either 34 00:02:08,160 --> 00:02:13,400 Speaker 1: experience antigenic shift or antigenic drift. Let's break that down. 35 00:02:14,000 --> 00:02:17,440 Speaker 1: In antigenic shift, a gnome strain of the flu morphs 36 00:02:17,480 --> 00:02:20,079 Speaker 1: into a novel strain that can cause a pandemic level 37 00:02:20,160 --> 00:02:24,360 Speaker 1: flu event, such as H one, N one and avian influenza. 38 00:02:24,840 --> 00:02:28,120 Speaker 1: This hardly ever happens. There have been just four influenza 39 00:02:28,120 --> 00:02:31,400 Speaker 1: pandemics in the last hundred years, but when it does, 40 00:02:31,680 --> 00:02:34,400 Speaker 1: it can be dire. The shift that resulted in the 41 00:02:34,600 --> 00:02:38,160 Speaker 1: H one N one influenza pandemic of en sometimes called 42 00:02:38,200 --> 00:02:42,519 Speaker 1: the Spanish flu, infected five hundred million people and killed 43 00:02:42,600 --> 00:02:46,360 Speaker 1: fifty million around the world. This was, of course, before 44 00:02:46,400 --> 00:02:50,920 Speaker 1: antibiotics were available to treat secondary bacterial infections associated with 45 00:02:50,960 --> 00:02:55,079 Speaker 1: the flu. Also, vaccines were not around to prevent infection 46 00:02:55,280 --> 00:03:00,240 Speaker 1: and lesson severity. But back to shift and drift. In 47 00:03:00,320 --> 00:03:05,280 Speaker 1: comparison to rare but dangerous shifts, antigenic drift happens all 48 00:03:05,280 --> 00:03:08,720 Speaker 1: the time with influenza, resulting in many small changes to 49 00:03:08,760 --> 00:03:11,600 Speaker 1: the virus, which makes it tricky for vaccine developers to 50 00:03:11,720 --> 00:03:14,640 Speaker 1: nail even the annual flu virus squarely on the head. 51 00:03:15,520 --> 00:03:18,799 Speaker 1: Poland said, so, what happens is about a quarter of 52 00:03:18,840 --> 00:03:22,520 Speaker 1: a million viruses are isolated every year and genetically sequenced 53 00:03:22,560 --> 00:03:25,840 Speaker 1: to give us an idea of what's circulating. It takes 54 00:03:25,880 --> 00:03:29,000 Speaker 1: six months or so to develop and distribute the flu vaccine. 55 00:03:29,520 --> 00:03:32,120 Speaker 1: By that time, many of the strains have drifted to 56 00:03:32,120 --> 00:03:36,320 Speaker 1: the point where they have next to no protection, meaning 57 00:03:36,600 --> 00:03:38,520 Speaker 1: that one of the reasons you can still get the 58 00:03:38,520 --> 00:03:41,520 Speaker 1: flu after receiving a flu vaccine is that the strain 59 00:03:41,600 --> 00:03:45,480 Speaker 1: you get may have developed after the vaccine was created. Again, 60 00:03:45,560 --> 00:03:48,840 Speaker 1: these things take time, but it's worth noting here that 61 00:03:48,960 --> 00:03:52,440 Speaker 1: even a mismatched vaccine is known to reduce the severity 62 00:03:52,440 --> 00:03:55,520 Speaker 1: of flu symptoms and the length of the overall illness, 63 00:03:55,560 --> 00:03:58,240 Speaker 1: so it's important to get the vaccine annually if you can. 64 00:03:58,960 --> 00:04:01,520 Speaker 1: After all, it's better to be bedridden for three days 65 00:04:01,560 --> 00:04:04,200 Speaker 1: than seven or worse, to end up in the hospital. 66 00:04:05,200 --> 00:04:08,640 Speaker 1: There are multiple roadblocks to developing a universal flu vaccine, 67 00:04:09,400 --> 00:04:12,600 Speaker 1: but a number of biotech companies and academics are currently 68 00:04:12,640 --> 00:04:16,320 Speaker 1: working to overcome them. Poland explained that one idea is 69 00:04:16,360 --> 00:04:21,320 Speaker 1: to develop broadly neutralizing antibodies to influenza viruses that would 70 00:04:21,360 --> 00:04:26,160 Speaker 1: ideally protect against every influenza strain. Let's talk a bit 71 00:04:26,160 --> 00:04:31,000 Speaker 1: about how the influenza virus works. Simply put, the influenza 72 00:04:31,080 --> 00:04:33,560 Speaker 1: virus is made up of a couple types of proteins 73 00:04:33,720 --> 00:04:38,880 Speaker 1: called H proteins and N proteins, plus a stock. Current 74 00:04:38,960 --> 00:04:41,880 Speaker 1: vaccines attempt to teach your immune system how to hit 75 00:04:42,080 --> 00:04:45,000 Speaker 1: the H and N proteins, which are what the virus 76 00:04:45,120 --> 00:04:49,200 Speaker 1: uses to attach to and infect human cells. The problem 77 00:04:49,440 --> 00:04:52,599 Speaker 1: is that the exact makeup of those proteins drifts all 78 00:04:52,640 --> 00:04:57,320 Speaker 1: the time. By comparison, Poland explained, the stock portion is 79 00:04:57,400 --> 00:05:01,080 Speaker 1: relatively invariant. So the very it has been why don't 80 00:05:01,120 --> 00:05:04,560 Speaker 1: we shift how we technologically make flu vaccines to the 81 00:05:04,600 --> 00:05:08,920 Speaker 1: portion of the virus that doesn't shift and drift. Another 82 00:05:09,000 --> 00:05:13,279 Speaker 1: complexity is that flu viruses only infect the outermost cells 83 00:05:13,400 --> 00:05:16,200 Speaker 1: lining the respiratory tract, a part of what's called the 84 00:05:16,240 --> 00:05:21,080 Speaker 1: respiratory mucosa. Flu Viruses do not replicate throughout the body, 85 00:05:21,240 --> 00:05:24,960 Speaker 1: which is known as systemic replication. But we also spoke 86 00:05:25,000 --> 00:05:28,640 Speaker 1: with Dr Jeffrey Taubenberger, a virologist with the National Institute 87 00:05:28,680 --> 00:05:32,480 Speaker 1: of Allergy and Infectious Diseases. He said, if you look 88 00:05:32,480 --> 00:05:36,680 Speaker 1: at vaccines that provide good lifelong immunity, like measles, one 89 00:05:36,720 --> 00:05:39,200 Speaker 1: of the differences there is the kind of recall you 90 00:05:39,240 --> 00:05:42,559 Speaker 1: get from a systemic infection is different and much better. 91 00:05:43,560 --> 00:05:46,640 Speaker 1: There's something we're not understanding about how immunity at the 92 00:05:46,720 --> 00:05:50,839 Speaker 1: mucosal level sets up long term immunity. This kind of 93 00:05:50,839 --> 00:05:54,040 Speaker 1: protective immunity is hard to establish. We have to come 94 00:05:54,120 --> 00:05:57,240 Speaker 1: up with ways to bolster the mucosal immune responses to 95 00:05:57,279 --> 00:06:01,920 Speaker 1: give us better protection with these kinds of vaccine. So, 96 00:06:02,160 --> 00:06:06,480 Speaker 1: in other words, a universal vaccine would again ideally help 97 00:06:06,520 --> 00:06:09,560 Speaker 1: your immune system at the local level where the infection 98 00:06:09,600 --> 00:06:13,440 Speaker 1: actually occurs, but we just don't understand enough about how 99 00:06:13,480 --> 00:06:17,039 Speaker 1: that works in order to help. Once this gets worked out, 100 00:06:17,279 --> 00:06:20,160 Speaker 1: it could prove helpful in the development of universal vaccines 101 00:06:20,200 --> 00:06:26,200 Speaker 1: for other respiratory ailments like coronavirus. With any luck, one 102 00:06:26,279 --> 00:06:29,440 Speaker 1: or more of the numerous universal flu vaccine development efforts 103 00:06:29,480 --> 00:06:33,120 Speaker 1: currently going on will pan out. A version developed by 104 00:06:33,120 --> 00:06:36,159 Speaker 1: the pharmaceutical company Seek is about to enter phase three 105 00:06:36,200 --> 00:06:40,039 Speaker 1: clinical trials, and Dr Taubenberger's own team is hoping to 106 00:06:40,040 --> 00:06:44,359 Speaker 1: start human clinical trials on their vaccine in and don't 107 00:06:44,400 --> 00:06:47,520 Speaker 1: expect a universal flu vaccine to be ready too soon, though, 108 00:06:47,880 --> 00:06:50,640 Speaker 1: as it's an arduous undertaking that requires a lot of 109 00:06:50,680 --> 00:06:54,279 Speaker 1: trials to get FDA approval. It's a multi step process 110 00:06:54,320 --> 00:06:58,400 Speaker 1: that ensures that drugs are safe and effective. Poland explained. 111 00:06:58,920 --> 00:07:01,599 Speaker 1: Typically it takes hen or more years and it costs 112 00:07:01,600 --> 00:07:05,560 Speaker 1: about a billion dollars. We should note that in case 113 00:07:05,560 --> 00:07:08,560 Speaker 1: of emergency, new drugs can and have been brought through 114 00:07:08,600 --> 00:07:16,160 Speaker 1: the process sooner, but it takes again, work and money. 115 00:07:17,600 --> 00:07:19,920 Speaker 1: Today's episode was written by Aliya Hoyt and produced by 116 00:07:19,960 --> 00:07:22,320 Speaker 1: Tyler Clang. For more in this and lots of other topics, 117 00:07:22,400 --> 00:07:25,080 Speaker 1: visit how stuff works dot com. Brain Stuff is production 118 00:07:25,080 --> 00:07:27,920 Speaker 1: of iHeart Radio or more podcasts. My heart Radio visit 119 00:07:27,960 --> 00:07:30,720 Speaker 1: the iHeart Radio app, Apple Podcasts, or wherever you listen 120 00:07:30,800 --> 00:07:31,720 Speaker 1: to your favorite shows.