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Why women and men respond differently to vaccination? Implications. (5)
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Females and males respond differently to vaccinations. You are a prominent immunologist, you studied male and female differences in response to BCG vaccinations, measles, mumps, and rubella vaccinations, gender differences in response to influenza vaccinations also exist. How and why males and females respond differently to vaccination? Why is this relevant? Again, you use the word gender incorrectly. Both sexes and the gender have an impact on the response to vaccination. What exactly are vaccines? A vaccine tends to be a part of a pathogen. For example, when we talk about viruses, vaccine is part of a virus. Vaccine is used to stimulate challenged individuals. Vaccine stimulates an immune response. I’ve already told you that the immune system is somewhat different between males and females in terms of cell numbers. If you look at just the X chromosomes, females are XX and males are XY. Look at the X chromosome. X chromosome will have a number of very important immune response genes. Amongst them are “toll-like receptors”. Just to make this somewhat simple. When you’re infected with a pathogen, the host will have to respond very rapidly. So we have this nonspecific surveillance system which picks up foreign viruses, foreign pathogens. Pathogens are recognized by these toll-like receptors. On the X chromosome a number of very critical toll-like receptors are present. Females are able to mount a robust immune response by virtue of that X chromosome. There can be a mutation in the X chromosome or in the genes on X chromosome. In males mutation on X chromosome is a major problem. With females by virtue of it being XX, it’s not a problem. In addition, there are a number of other genes which are encoded on the X chromosome. Again these genes are critical for immune response to be able to activate cells. To deal with any challenge and, specifically, a vaccine challenge, you want to mount a robust immune response. So females tend to respond to vaccines very well. And in fact, consideration should be given to this. When there aren’t enough vaccines available for a whole population, dose reduction of a vaccine with females to get the equivalent response is prudent. Males may need a double dose to generate the same immune reposes to vaccines as females. Unfortunately they don’t vaccinate males and females differently. During the flu pandemic some of us were commenting that if there was not going to be enough vaccine available, giving males and females different doses should be a serious consideration. You could do a rapid clinical trial to evaluate the extent of the immune response to a new vaccine in males and females with different dosing. But that’s interesting because obviously everybody is looking to make the COVID-19 coronavirus vaccine. But scaling up production and distribution of vaccine will initially be a major major issue. So those differences between males and females in vaccine reaction and dosage considerations will probably very likely come into play. One hopes that sex differences in vaccination will be in consideration. But in the past sex differences really hasn’t been considered for vaccines. Also vaccines dosing should be based on age of patient. We have this trivalent flu vaccine. I suspect in the US and in New York it’s the same as in Canada. For those over a certain age they get a higher dose because their immune response is less robust. So you give more of the vaccine challenge to invoke the same kind of immune response. So really dosing of a vaccine should be considered in the context of sex and also age.