Why Women’s Immune Systems Are Stronger Than Men’s

By Gemma Tarlach | December 23, 2013 2:00 pm

couple-with-the-fluWomen overreacting is an old and tired stereotype — but there’s some truth to it, at least immunologically speaking.

In a new study, researchers found that women’s immune systems responded more strongly than men’s to flu vaccine. Old and young women alike produced both more antibodies and a higher inflammatory cytokine count — one sign of potential immunological overreaction — than male participants.

His vs. Hers Immune System

While the gender gap in immune reactions has long been known, the mechanism behind it has remained a mystery. But in this study, the scientists identified a handful of genes, apparently regulated by testosterone, that they think are a key part of the response mechanism. The higher the testosterone levels of a participant, the lower the immunological reaction to vaccination.

Generally speaking, women have stronger immune system responses than men. The good news for women is that this “show no mercy” response means they are less prone to bacterial, viral, fungal and other types of infection than the dudes are. The flip side, however, is that women’s immune systems are more likely to overreact.

When an immune system is overstimulated, it can attack healthy tissue, which is what happens with autoimmune diseases such as lupus. It can also cause potentially fatal post-infection complications, such as a cytokine storm after getting the flu, in which an overproduction of immune cells overwhelm the body’s normal functions.

It’s in the Genes

Researchers in the current study analyzed immune response to a seasonal flu vaccine in 37 men and 54 women aged 20 to 89. From blood samples they were able to isolate a cluster of genes involved in fat metabolism that were also associated with the amount of antibodies and cytokines produced. The genes appear to be regulated by testosterone, and researchers found the male participants with the highest levels of the hormone had the lowest antibody response.

Previous research has focused on how genes located on the sex chromosomes might affect the immune response to vaccination. But by exploring the role of testosterone, today’s findings, published in the Proceedings of the National Academy of Sciences, could be a new avenue for understanding — and eventually treating —immunological overreactions. The results also point to possible reasons for women having a higher rate of autoimmune disease.

Image credit: bikeriderlondon/Shutterstock

CATEGORIZED UNDER: Health & Medicine, top posts
  • Xiaowei Song

    I figured out the situation some days ago. It is an really interesting phenomenon.

  • Dimitri Ledkovsky

    Seasonal flu vaccines are adulterated and rarely are made to target the flu strain at hand. They are just a big money maker for the medical/industrial complex. Opt out!

    • http://blogs.discovermagazine.com Ron Hansing

      The flu vaccine is an attempt to predict the dominant stain. Regardless, is is not a big money maker. And even if the vaccine is not specific, there are a number of closely related antibodies that cross react and hence, decrease the severity of the disease.
      This probabley explains why we have not had a 1918 virulent epidemics since then.

      • http://blogs.discovermagazine.com James Logan

        Ron + Jaia:
        You are both partially right. However, you both are mostly wrong! The flu vaccine is the CDC “guess” as to what the dominant strain[s] will be each year. The CDC has been wrong 4 of the last 10 years.
        The CDC also admits [ when questioned ] that 50% of people that get the flu shot will get the flu! The so called “dead Viruses” claim that can’t hurt you doesn’t pass the “smell test”.
        The flu vaccine is an “orphan drug” manufactured by whatever company will accept the contract that the government will pay for x million doses and provide immunity from lawsuits.
        If you think that “Big Brother” is telling you the truth about ANYTHING please reread a book named “1984” and listen to what Eric Snowden has been saying about what Your Government is saying about their “monitoring” of phone+ emails. You can that the government is lying is when their lips move!

        • dazyduck

          Just curious as to your sources for the statements above that you have made. Bet you do not have any. You say 50% get the shot and then get the flu. Where did you get those numbers? Many times the severity of the flu is greatly lessened by having had the shot. No reputable source has never said that we will never get the flu if we get the vaccine.
          We can catch a different strain of the virus weeks after the flu shot but blame it on the shot itself. The flu ”virus” in the shots are D E A D. Some people have an ”immune response” to the proteins in the virus and/or the other substances in the shot. This is not the same as ‘getting the flu from the shot’. You need to do a bit of reading and learning and ignore the legends of the beauty shop or the bar.

          • http://blogs.discovermagazine.com Brent Whote

            But don’tcha know that if you make declarative statements in an authoritative tone, then those with a predisposition to believe you will then quote you ad-nauseum? Folks like James just love preaching to their choir, and if you are not in their choir then you must be either ignorant or stupid.

    • jaia

      Seasonal flu vaccines are made to target the predicted dominant strains for that season. That’s because it takes months to manufacture the vaccine with current technology. Sometimes, the match is good; other times, not so good. On average, you’re still better off getting the vaccine, especially if you’re at high risk for complications or interact with people who are.

      As for “adulterated”, I have no idea what you mean.

      • http://blogs.discovermagazine.com Brent Whote

        Technology has been developed to produce the influenza vaccine much more rapidly. As to why that technology is not yet being used … well I don’t want to go there, but perals Demitri will.

      • MOnodb Bart

        You did a very good job with just one paragraph! I think Dimitri means, in effect, “contaminated” by his use of “adulterated”. I also suspect that Dimitri is rather fringy.

  • confused

    Wondering if a male wrote this article. And, why weren’t the studies conducted on the same age groups of men and women?

  • Carmel Hopkins

    That’s why I always get a little stuffy and chill after I’ve had the flu shot!

  • Jon Ripley

    The immune system genes are carried on the “X” chromosome, and women have 2 “X” chromosomes, so they have a built in back-up of immune response. If the primary response genes don’t respond, the secondary’s do, that’s why they don’t have “double” immunity, it only kicks-in when needed. This explains why worldwide, women live longer than men, longer by approximately 10 %.

  • Charles Knouse

    What most people don’t know about vaccines, and why you should think carefully before getting vaccinated, is:
    1. the flu vaccine contains an mercury-organo compound called thiomersal; this not only contributes to injection of very toxic mercury, it causes a two-week period of severe depression of your immune system, leaving you wide open to viruses of any kind, including viruses you already have but are normally being kept in check by your own immune system. Heart inflammation (myocarditis, endocarditis, etc.), shingles (varicella zoster), herpes outbreaks (herpes simplex I or II), PPV (papilloma virus), cytomegalovirus, are just a few things that can happen to you in those two weeks, along with getting the flu lol!!!!!!
    2. because the contract goes to the low bidder, AND especially because the manufacturer has NO liability by government fiat, there is no incentive for the manufacturer to go to any extra lengths to ensure purity…did you know the cultures they use to grow the virus for the vaccine can be contaminated by all sorts of xenoviruses? Did you know that all species of eukaryotic cells harbor silent viral genes that can become activated and science really doesn’t understand these silent genes yet? So, when the vaccine is grown in chicken eggs, or monkey cells, or variant human cells in culture, how do you know you’re not being injected with xenoviruses from those cultures? The fact is….you don’t. Perhaps you should consider intravenous vitamin C from a naturopathic physician for flu season instead of the vaccine. Do you really trust your government…really? Really???

    • http://blogs.discovermagazine.com Brent Whote

      Charles, you present a classic exampe of cherry picking, shallow understanding and misrepresentation of acs with just enough truthful information to sound legitimate. I don’t have the credentials to feel competent to pick apart your case and make you appear to be a fool, but even as lay person, it woud be easy to do so. I hope that a legitimate expert will weigh in toset you straight.

      • Charles Knouse

        So, Brent, I suppose if I pointed out that castor beans contain ricin, I would be cherry-picking facts and maligning the poor castor bean? I fail to see how providing a few kinda important facts, for thoughtful people to follow up on, so they can make an informed decision of their own, is a bad thing.

  • Puppa Moore

    Just curious, is it necessary to take this vaccine (from your point of view, no need historical facts, just yes/no & why)?
    I have never had a shot of it, and i strongly believe, that if you are not ill, do not make yourself ill with external sourses.
    P.S. I know a lot of ppl, who did not take any vaccines yet, and we have flu more rare, then those who really had flu vaccine shot ( this is not strongly regulated here, so everyone are allowed to choose have it or not)

  • AnimeTheoryXN

    Me (a male) and my sister live in the same environment. Me and my father and brother rarely ever get ill. I have a record of 100% attendance for 2 years straight in my school. Speaking of illness my sister is ill today. Also I am more fitter, stronger and taller. I am also more skinnier, how can wommen be better health than men. Also when i do get ill i get bad headache and vomit, but less than 7 hours I feel better again! HOW?
    It just depends on some people, just becuase you are a boy or man does not mean you have weak immune system.


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