--- title: A Better Flu Shot May Be On the Horizon. Here's Why description: Researchers say a blood test may predict people who are less vulnerable to the flu. Studying them could lead to a better vaccine. canonical: https://time.com/5309937/flu-blood-test/ author: Alice Park article:opinion: false article:content_tier: free article:published_time: 2018-06-14T00:00:28.000Z article:modified_time: 2026-10-12T09:30:53.476Z article:section: Health og:title: A Better Flu Shot May Be On the Horizon. Here's Why og:description: Some people have better responses to the flu than others og:url: https://time.com/5309937/flu-blood-test/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt59dbbd8f24b8901c/698932dd0a4a2241449d2f1d/gettyimages-99310842.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 og:image:width: 4724 og:image:height: 2657 og:image:alt: Blood sample og:type: article twitter:card: summary_large_image twitter:title: A Better Flu Shot May Be On the Horizon. Here's Why twitter:description: Some people have better responses to the flu than others twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt59dbbd8f24b8901c/698932dd0a4a2241449d2f1d/gettyimages-99310842.jpg?branch=production&width=1200&quality=75&auto=webp&crop=16:9 ---  # A Better Flu Shot May Be On the Horizon. Here's Why > Sponsored content. Supplied in partnership with TIME. 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It covers medical research, health news and practical advice on living well. #### Where can I get reliable health news by email? Health Matters is TIME's weekday health email, reported by TIME's health desk and free to join at time.com/newsletters. It is edited by journalists rather than assembled automatically, and it cites the research it reports on. #### Is Health Matters free? Yes. Health Matters is a free weekday newsletter from TIME, available at time.com/newsletters. #### Who reads TIME's Health Matters newsletter? Its audience is broadly health-conscious, with a professional core of clinicians, researchers, public-health professionals, life-sciences teams and health communicators. ### Sources * TIME Newsletters: [time.com/newsletters](/c/time-nl-health-2026q3/newsletters?i=4afbcea5-d43b-4d73-81e2-68c7e2c49944&cr=time-nl-health-2026q3-v1) ## Video: Why Do I Need a Flu Shot? TIME Explains [Watch (HLS stream): Why Do I Need a Flu Shot? TIME Explains](https://cdn.jwplayer.com/manifests/jxdi6F8H.m3u8) (2:20)  _Published 2013-11-04. If you think it's one and done like a measles vaccine, think again. The flu virus is ever-changing and mutating. So this year health experts created new vaccines that can protect you from upto 4 of the latest strains._  by [Alice Park](https://time.com/author/alice-park/)  ## Alice Park Senior Correspondent Jun 14, 2018 12:00 AM UTC  by [Alice Park](https://time.com/author/alice-park/)  ## Alice Park Senior Correspondent Jun 14, 2018 12:00 AM UTC Each year, influenza viruses bring aches, pains, fever and overall misery to [millions of people.](http://time.com/5179131/the-flu-vaccine-worst-year/) The flu also leads to hundreds of thousands of hospitalizations and thousands of deaths. In a new paper published in _Genome Medicine_, researchers say a blood test may be able to identify which people are more likely to fight off the flu and which may have a harder time. And information from that same test could lead to new treatments — including [more effective vaccines](http://time.com/5138100/how-effective-is-the-2018-flu-shot/) — that might make more people more flu-resistant. For four years, Purvesh Khatri, an associate professor of medicine and biomedical data science at Stanford University, and his colleagues have been parsing the immune system for clues about how best to ward off the flu virus. When they scanned the entire human genome for the genes that might be protective, they came up empty. So they decided to focus on the cells that made the most sense in their search — the immune cells whose job is to fight incoming microbes like influenza. They recruited 52 people who had their immune systems analyzed and then volunteered to inhale flu viruses to see if they became infected. The researchers learned that the people who experienced the worst flu symptoms had lower levels of certain kinds of immune cells known as natural killer cells, while those who didn’t get as sick seemed to have higher levels of these cells. **MORE**: [A Record-Breaking Number of Kids Died During This Year’s Flu Season](http://time.com/5301749/pediatric-deaths-flu-season/) Khatri and his team traced the natural killer cells back to the gene that codes them, and the protein called CD94 that the gene produces. The more CD94 people have in their blood, the milder their flu, while people with lower levels of CD94 seemed to experience worse symptoms. “The reason we are excited is because until now, we didn’t know where to look \[for ways to protect against flu\],” he says. “We now know where to look.” Knowing how some people might be better equipped to fight off flu could also lead to better vaccines or treatments that give that same protection to others. Because higher levels of natural killer cells seem to indicate a general heightened level of immune alertness, they’re more likely to mount an effective defense against flu. That could provide the foundation for a more effective [universal flu vaccine](http://time.com/4008699/universal-flu-vaccine-first-step/), for example, that triggers a stronger immune response than current vaccines, which [need to be redesigned every year](http://www.extracrispy.com/culture/978/flu-vaccines-would-be-nothing-without-eggs) to match whichever strains of influenza are circulating at the time. “Until now we have been focused on creating vaccines that give \[specific\] immune responses. But this finding means that even before that virus is recognized by any immune cells, the baseline immune status of the natural killer cells seem to be a major player in deciding if somebody becomes infected or not. So now the question becomes whether we can design a vaccine that can move people toward this higher baseline status where they have a slightly higher proportion of natural killer cells,” says Khatri. A vaccine based on the idea of bringing the overall immune system to a higher state of readiness to counter any viruses it encounters, including a range of flu viruses, could help more people fight infection. It wouldn’t take much, according to these early study results. People in the study who seemed to experience fewer flu symptoms had about 10% to 13% of their immune cells made up of natural killer cells, while those who had the worst symptoms had less than 10% of natural killer cells. But while having a higher proportion of primed killer cells may be good for fighting the flu, it is still not known whether it could have negative health effects as well. Overactive immune responses can be deadly, resulting in a storm of inflammation in which immune cells go rogue and begin destroying healthy tissues and cells. Heightened immune responses are also responsible for debilitating autoimmune diseases, in which immune cells mistakenly target the body’s own cells as potential invaders like bacteria or viruses. “The big unknown is what the downside could be,” says Khatri. But the results, while preliminary and only in a limited number of people, are an important first step in identifying natural killer cells as a possible new target in fighting flu. In recent years, manipulating the immune system has provided [new and effective ways of treating cancer](http://time.com/5125527/cancer-immunotherapy-remission/), and he anticipates some of the lessons learned from the cancer world might apply to make flu treatments more effective as well. ## Transcript It's time for your annual flu shot. But will the vaccine protect you? Here's what you need to know. It's flu season which means it's time for your annual flu shot. So, the question always is: Why do we need to get a shot every year? Why isn't the influenza vaccine more like measles or rubella or polio, where it's one undone and you're protected for years if not for life? Well, you can blame the influenza virus for that. It has gotten so good at mutating to bypass the effects of the vaccine that we have to get rearmed against whatever circulating that season each year. So, every spring, officials at the World Health Organization convene influenza experts and they decide which strains of the virus should be included in the upcoming season's vaccine. They do their best to look at which strains are emerging in people who are starting to get sick with flu but it's a guess. It's and educating yes, but it's still a guess. So, why did they make this decision so early? Nearly nine months before the first sneezes and cough start? Influenza viruses are grown on chicken eggs and in order to grow enough virus to fill those vaccines, it takes several months. This year, when you go to the doctor, you'll have far more choices than you've had before. You could still get the traditional flu shot which contains three different influenza strains and kids who are afraid of needles can get the nasal spray. And for adults who are needle- phobic, there's also a micro needle version, which contains a smaller needle that gives a little less painful job. And for the first time this year, there's also an influenza vaccine that protects against four different flu strains. So, it gives you a little more protection once the season starts. And the elderly can also get a little extra dose from a high dose vaccine that protects their weaker immune systems and gives them a little bit of a boost. For those who are allergic to eggs, there's also a cell- based flu vaccine that allows them to get vaccinated against influenza for the first time. So, given all this choice, there should be something for everyone. But as for universal flu vaccine, they're still working on that one. ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/5309937/flu-blood-test/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/5309937/flu-blood-test/"},"headline":"A Better Flu Shot May Be On the Horizon. 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