The Future of Vaccines: Part One

past couple of centuries. Yeah, we're talking vaccines saving literally millions countless lives, you could say, because there's no way of knowing. I'm pray the other but but clare might have all gotten better anyway, probably not all of them. Probably probably not, but maybastically speaking, maybe a few. But at any rate, we know that millions of people are

alive today because of vaccines. Yeah, and we wanted to cover it because it's been an interesting journey seeing how the public relationship with the science of vaccines has changed

over my lifetime. Yeah. Yeah, I remember when I was a kid, vaccines just being um, being a kind of uncontroversial part of medicine as far as I knew, maybe I wasn't aware of whatever controversies may have existed, then, I think they were relatively controversial, uncontroversial for the entire span of their existence up until like the nineties, at least at least unless you kept like the first few decades of vaccination, in which case there was some contention.

But well that's because they didn't work once they were established from that point forward. Yeah, people really didn't have a whole lot of contentious things to say until the nineties.

But we'll go into that probably more in part two. Yeah, but one of the things that's interesting to look at from our perspective on vaccines is that I think the public has sort of lost track of the progress of vaccines in the future or projections about vaccines, because we live in a climate now where news stories about vaccines tend to be about the political controversy people who, you know, activist groups who are opposed to vaccines for some reason,

instead of about what new things vaccines could do in a medical sense. Right. Yeah, So we've got a lot to say about vaccines, and in this episode we're really going to be looking it's it's it's almost like it's a stuff you missed in history class episode instead of forward thinking episode. Yeah. Yeah, we're talking about the future of vaccines, and by the future we mean the past

right in part one. In part one, Yeah, in part two, we're going to go into some of the new techniques that are being developed in some of the new ways that this sort of technology is going to continue to change our lives. Uh and you know. But but right in this first episode, would like to clear up a little bit of the confusion perhaps about what vaccines are, how they work, how they have worked, and what they are doing for us right now. Yeah, exactly, So we

have to have a basic understanding to work from. So at the very beginning, if you want to take a super bird's eye view, vaccines essentially are a method of teaching our immune systems how to respond to specific pathogens, specific disease carrying microbes. Yeah. I tend to think about

vaccines sort of at two levels of resolution. One of them is the specific sense, in which most of the time, especially with with infectious diseases, there it's referring to using a damaged, you're killed version of that disease in order to teach your body's immune system how to respond to it. But then there's also a broader sense of looking at the concept of vaccination as essentially a preventative measure in medicine that gives you resistance or immunity to a condition

or disease before you get it. Yes, and inoculation, it's pre therapy. And also it's it's not just for the individual, right, you know, talking about vaccination, this is really for the good of large groups of people because often we're talking about diseases that can be contagious. Now, not all diseases that you would get vaccinations for our contagious, but several of them are, and you would like to have a vaccinated population to prevent that kind of outbreak it reaching

an epidemic, you know, proportion if possible. And just just to be clear, when I'm saying diseases that aren't contagious, I'm talking about human to human contagion. Right. Some diseases, uh, you you catch from other sources, like malaria is spread through mosquito bites, but not through human to human contact. And we don't have a vaccine from malaria. Yes spoiler alert from part two, but yes, exactly, we do not yet have a vaccine from malaria. And there's very good

reasons why we have not yet developed one. We'll talk about that in part but we did have one shingles. Yes, shingles being the same actual virus that causes chicken pox, but the shingles variant is not not human to human contagious. If I were to develop shingles, I would not be able to pass it on to my coworkers here. I would just be in a lot of discomfort. Uh So, there are different types of diseases, and both bacterial and viral diseases are are represented among the vaccinations that we

can get. It's not just one or the other. You know, we talked about antibiotics. That's typically something you would use for a bacterial infection, but only something you can use bacterial infection, right, So in this case, vaccines could be used for either um and when in the case of malaria, that's parasitic. But again we'll talk about that more in portant too. So you might think, all right, well, how

far back to this does this idea date? Well, I'd imagine that before we had vaccines, somebody had to have observe that for some diseases, most people only got them once, And in fact that did happen, and one of the earliest records we have dates back to four twenty nine b c E. And that was when a Greek historian whose name I am going to spell and then attempt to say it's throucidities. Throucidities, is that it? Yeah, I've

never ever heard it before. Come on, he's probably talking about smallpox in Athens, right, And look, I was a Shakespearean scholar. I had little Latin and less Greek, so uh, thucidities then, at any rate, thlucidities observed in four nine b C that people who were exposed to smallpox and recovered did not seem to get it again, whether they were around lots of people at small pox or not. Uh. And it was this idea that kind of eventually evolved.

And what's interesting is that evolved in different places around the world, more or less at around the same time. We don't have a record of it originating in one part of the world and then spreading, like the knowledge spreading of how to make a practical application of this knowledge.

It may very well be that it independently was developed in various areas around the world more or less than the same time frame, but there do seem to be ancient civilizations that figured out how to make use of this observation, not just kind of, hey, that's an interesting fact you can only get smallpox once, but thinking that maybe if we, you know, kind of scrape off somebody's smallpox scabs and jam them up your nose, that might help you similar to that, Not quite that level, but yes,

uh so far off. This is the predecessor to vaccination that is called vary elation. Are generally called vary elation. There are some other names like ingrafting that will talk about later there it's essentially the same thing. Yeah, I've read this showed up in like China and India, Yeah, and Africa. Yeah, it happened. Happened to show up in a lot of different places all around again the same general time frame. But vary elation involves pretty much what

you were talking about. You would take someone who has not yet been infected by a disease like smallpox, and you would end up scratching their skin and then introducing some infected material, usually scabs or possibly pus, from someone who already had contracted a weakened version of small box. Someone who was had a mild case. Someone yeah, who was surviving. Yeah, who had it but was doing okay, Yeah, someone had it enough to have some scabs. Yeah. Well,

I mean that's a basic symptom of smallpox. You know, it's not like it's not like, oh, well they've got smallpox, but don't worry, they have the non scabby kind. It was at any rate, it was It was taken from people who had the mild cases because the thought was, well, it's more likely to be less deadly than the people who had really uh you know, debilitating and often fatal

cases of smallpox. So then they would expose the cut to the healthy person, healthy person to this infected material, essentially rubbing the infected material, sometimes using a lancet to introduce infected material in underneath the skin, essentially injecting it into the bloodstream of the uninfect in person. The uninfected person then would become an infected person. This was the

process of going from uninfected to totally infected. But it would normally result in another mild case, and more often than not, certainly more often than someone catch catching the

disease naturally through person to person contact or whatever. Um would recover and so then once they recovered again, yeah, no matter what how powerful the strain was, they wouldn't get that particular disease again, specifically smallpox, and the Chinese were regularly performing vary elation treatments by one a d and this spread probably outward from these individual communities, not necessarily from uh you know, from from east to west,

although that did eventually happen, but much much later. Uh So, the Chinese physicians what they would typically do is a lymph from a patient who had a mild case of this disease and put that in a bottle and the lymph would dry out, and they would usually wait a couple of weeks before they would use it. And this actually had the effect of either killing or rendering inert most of the virus inside that sample, which is a basic idea that's used in vaccines today, is using either

UH attenuated or dead versions of the pathogen. And just so happens that they were doing it and and it worked, was an effective treatment belief for them. Yeah, So, if we if we fast forward to the early seventeen hundreds, that was when UH inoculation, this idea of introducing infective material and a healthy person to prevent them from catching something. Later so you say early seventy. That sounds like we're

not to Jenner yet. No, we're not degener yet. There was a lady by the name of a lady as in a peer by the name lady Mary Wortley Montague. Is lady on the same level as what lord? Yes? Yes, is that a level or is that just a general? It's a peerage, is part of the peerage. Um. So she was the wife of a British ambassador to Turkey and observed while in Turkey this practice of very elation. She brought it back to England. She called the practice in grafting. And she had a very um personal reason

for for practicing this. Her brother had died from smallpox, and she herself had had caught smallpox. Survived, but she was terribly scarred by it. She was someone who had been renowned for her beauty in her youth, and she was determined to make certain that her children did not suffer the same fate as her brother or herself, and

so she used this approach. Um. In this version, you would take pus from a blister that was formed on a you know, if someone who had smallpox had developed and preferably a mild case of it and then introduced it into the bloodstream of an uninfected person using a lancet. So it again ended up kind of catching on. It wasn't infectious or anything, but it did catch on in England and was over time a pretty popular way of treating people so that they would not catch smallpox. But

it came with some slight drawbacks. Yeah, as you may be able to imagine anyone who heard, you know, heard us described this process and immediately went that's a really good way to catch lots of other diseases from somebody. And in fact it was a good way. So if you were person the person who is suffering from a mild case of small pox also happened to be suffering from something like syphilis or tuberculosis, then there was a strong possibility you were prubbing their bodily tissue into your

bodily to issue. Yeah, hey, that just sounds like even more vaccines, right, Probably didn't work that word that way for tuberculosis or syphilis. No, not all diseases are are ones that you can use this particular approach to to become immune to those diseases. Well, yeah, and it wouldn't follow that if you had a particularly weak version of smallpox, that your versions of those other diseases would be weak strains as well. That's also true. So yeah, this this

was an issue. Now we skip ahead to six, and that's where we get to Edward Jenner, who is often credited as being the person who quote unquote discovered vaccines. It's a little bit of a misnomer, a little bit of misinformation, but usually any time you say that a single person discovered a thing, it's it's sort of ignoring the hundreds of years of scientific history right back to

their discovery. I think the best we can say is that Jenner was the first to really apply the scientific method you staying a hypothesis to prove the underlying uh foundation was sound. Yeah, and don't get me wrong, like he did amazing work, like especially considering that it was sevent y'all. Yeah, and he he threw in his personal like fortune is probably being too too grand a word.

He put a lot of his time and money into this to the point where he was, uh, you know, not doing so great and as far financially speaking while he was working on this, but he believed in it wholeheartedly. So he continued to pursue it. Uh, he had been inoculated against smallpox when he was a kid using the

very elation technique. Yeah. But so there is a distinction to make with jennerous technique versus the very elation technique, right, which is the very elation technique says, let's take a weak version of smallpox and give it to you and hope it doesn't kill you or make you really sick, and you'll become immune. Jenner found a sort of run around this, right, He was like, well, what if we

took a similar disease that doesn't really hurt humans? Yeah, I mean, cow pox does create some pretty nasty pustules, but tends to usually, it doesn't last that long, and it's rarely serious. It's kind of alone the lines of like a chicken pox for someone who's young, right. You know, obviously as you get older, if you have never had chicken pox, it can be a more serious health hazard.

But uh, yeah, he had heard these tales about dairy maids who had suffered cow pox but then never ever suffering from smallpox, even if they were exposed to it um. And so he started to form this hypothesis that perhaps whatever caused cow pox was similar enough to smallpox that if you were to expose someone to it in this approach, they would then be immune to smallpox as well, which

would be incredibly helpful. Right, So he ended up taking infective material from a woman named Sarah Nelms who was a dairy maid who was suffering cow pox and uh and ended up uh introducing into the blood stream of a young boy named James Phipps, and then later used the vary elation technique to introduce smallpox to the boy's blood and he was completely unaffected. He didn't get sick.

So in other words, it was taking the the very elation approach, like still trying to safely introduce a mild case of smallpox to the boy to see if in fact he would have the symptoms, because often people would have symptoms for a short while, recover and then they'd be immune. The boy never even developed symptoms, thus showing that, oh, this cow pox approach is working. Now did the boy know what was going on here? Yeah, this this is

a little bit less controlled. Either way, vary elation would have been the method to in oculate him against smallpox. So it turned out that you know, even if it even if the cow pox thing hadn't worked. This is this was the accepted way to inoculate someone against smallpox. Um. Probably still a little ethically questionable today, but but you know,

the point is that the entire past is ethically questionable. Yeah. Uh. And so uh, you know, keep in mind Jenner himself, he was not just a physician, not like a country doctor or anything. He had actually studied under some of the most famous surgeons in England at the time. Uh, and had even studied other fields of science, including biology. He had helped classify species that were brought back by Captain Cook after Cook's first voyage. Yeah. So he was

very much involved in the scientific community. And he wrote up a paper about how he used cow pox to inoculate against smallpox, and and uh ended up submitting it to the Royal Society, but they rejected the paper. They did not think that it was worthy of publication. And so he would end up self publishing a booklet, uh, something that I can come traditions still kept alive today, exactly. Um, And I'll show you His booklet had a catchy title.

It was an inquiry into the causes and effects of very early vaccinate a disease discovered in some of the western counties of England, particularly Gloucestershire, and known by the name of cow pox. That just sprawls right off the tongue. It does. Oh wow, I'm putting this together in my brain right now, and I've never realized it before. Spanish for cow is voca, probably connecting to Latin voca meaning cow meaning. The word vaccine comes from the word for

cow cow poxes uh in Latin is vaccinia. So he named the process vaccinations. Vaccination refers specifically to using cow pox to protect against smallpox, but has been since broadly applied to this procedure for all sorts of different diseases. But yes, originally it all had to do with cow pox and smallpox, uh, which I thought. I tried to throw in at least one little cool truth nugget that's gonna really get you, you know, right, right right and right in the thinking parts. That was my goal at

any rate. Um. So, Jenner faced a little bit of opposition to his approach because obviously, anytime you come up with a different method of doing something than the standard method, there's inertia to overcome, right, But other physicians physicians soon began to employ this vaccination technique, and by eighteen hundred the practice had spread from UK to Europe and even

to America. Thomas Jefferson himself became an advocate for vaccinations after Professor Benjamin Waterhouse of Harvard University demonstrated its efficacy. So Waterhouse had received a sample that ultimately came from Jenner of the cow pox um Uh, material that could be used for vaccinations. Uh. It got to him by way of another scientist. But that's how it got over

to America. And Jenner continued to push for vaccination, often again at his own expense, but eventually was recognized by a British parliament for his contributions to the health and welfare of the nation, and they ultimately awarded him with about thirty thousand pounds sterling, which was no small sum. Yeah, that's that's not it. That's not a joke right now. No, it's it's a healthy dose of cash right now. Back then,

it was, you know, an enormous sum of money. Uh. And by eighteen forty, vaccinations had completely replaced vary elation in the UK. In fact, vary elation had become prohibited. So you could only go forward with vaccination at that point. Um. And again, Jenner was not the first guy to try this out. There were some other records that predate his work, but he was the first to apply the scientific method to establish that, in fact, this was a sound method

of preventing disease. But this is still before we had realized that diseases are caused by germs. Germ theory was not a thing, which means that there was still the risk of cross contamination where you could still introduce something like syphilis or tuberculosis in this process just because people weren't sterilizing equipment, equipment. Essentially, it was it wasn't until like the eighteen fifties that germ theory really caught on, like like really really took hold. So, which is so

crazy to me thinking that that's that it was that late. Yeah, so so yeah, And I mean you you can read accounts in the Civil War of doctors who just didn't take to that whole idea of washing up between patients, I mean, just gonna get hands bloody again. Yeah, but at any rate, you know, this is uh still was quite an issue here. But but we also had debates that raged on other elements of vaccinations, and they went

on well after or the eighteen hundreds. So, for example, UH, there was the debate about the merits of a live culture of whatever the pathogen is, whether it's viral or bacterial, versus a dead sample, a dead or or inactive sample, and depending upon the vaccination, that actually does make a

big difference. But a big debate that was right on this this very very subject was between Jonas Salk, who was the uh, the man who essentially created the polio vaccine that all but wiped out polio um, although there's still some parts of the world where polio is still very much a problem. Uh and another physician by the name of Albert Sabine, who argued for a live polio vaccine as opposed to a dead polio vaccine. Salk went out on that one, by the way, so at any rate, UM.

So that that's the history, but that doesn't tell us exactly what is happening in our immune systems when we encounter one of these pathogens, whether it's from a vaccine or some other source, like if we're actually catching a disease. So we in order to understand how vaccines work, we kind of have to look into the immune system of the human body. So to understand how our immune system works.

I've got a cast of characters that we need to familiarize ourselves with, the dramatis persona if you will, Yeah, you know drama. The cast of characters from Inner Space or the Fantastic Voyage does not does not have inner space to sale is Martin short, right, which is which they both are. Both are tiny people going in the body right, Yes, inner Space was the comedy, but at any rate, So one of the first things we have to discuss that are several different subtypes of white blood

cells actually play an important part here. We have macro flogees. Uh, you guys know what macro floge means. It means big eater. Yes, macrobe being big and foge being to eat. So these are these are cells that quote unquote eat other cells, like consume other cells or other material doesn't necessarily mean another cell. So they eat things like microbes, like foreign microbes that come into the bloodstream. But they also eat other stuff like just de try to you know, the

garbage that accumulates in our bodies. If we didn't have these, we would are our blood would get pretty toxic pretty fast. Uh. Then we have the idea of antigens. When a mac macroflage eats um a microbe, it leaves behind, it saves a special part of that microbe called the antigen. They they're actually molecular markers that yeah. Yeah, it's essentially kind of like an identifying badge that says, this is what

this thing is. Uh. And antigens are what alert the immune system that are potentially harmful foreign being is present in the body. So this is what sets off the red alert inside of your your body when your immune system starts to really kick in and you start feeling sick. This is what is going on. It's identified that there's something hanky going down. Yeah. So, uh, antigens are pretty interesting.

When the macroflage eats on MicroB, it saves that antigen, which helps your immune system recognize future infections from that same pathogen. It's it's the body's equivalent of the wall where you put up that do not accept checks from this person. Yeah, yeah, exactly. And I can't overstate how

completely rad this process is. Uh. And that's the like official scientific term is radh Because the cells in your immune system make these these antigen's part of their own genetic code and then use intracellular communication to spread word about that antigen. It's it's really beautiful, so let's talk about it. Yeah yeah, So now we've got some other

white blood cell types. We need to talk about lymphocytes. Uh, this is also part of the immune system, obviously, and within lymphocytes, we have two broad categories of cells, T cells and B cells. T cells are thymus cells, and they can run either offense or defense. So they're the iron man players in the immune system, right. They can switch off. Um, actually technically you've got two different types.

But in the offense mode, what they focus on our human cells that have been infected by some sort of pathogen. A lot of pathogens are essentially invading human cells, overtaking the molecular machinery inside the cells for their own doc purposes, usually to generate more of themselves, especially in the case of viruses. Yeah, so it's all about, Hey, let's use the body's machinery against itself and make more of us, y'all. And so that's what tends to happen. So T cells

they wage chemical warfare on your body's infected cells. So there are cells that originally belong to you, but now and compromised by the enemy, and it's time to carpet bomb. Yeah, it's to eliminate with extreme prejudice and uh. And the idea being that if you can kill the host cell, then the pathogen will not be able to multiply and you can get the upper hand on an infection defensively.

T cells secrete chemical signals that alert the other elements of the immune system to the presence of a harmful micro and this is called cell mediated immune response. And then you have the B cells. B cells are responsible for making antibodies. Now, antibodies are molecular weapons that lock onto antigens on microbes. So you can think of it like lock and key or a jigsaw puzzle, where a particular antibody will fit snugly against a particular antigen, which

means that not every antibody works on every antigen. Right, if a disease, if you if you come in contact with a specific disease and your body has not ever encountered that before, the antibodies at deuces won't fit that disease, not initially. Yeah. Yeah, these cells are running around like I'm trying to help. I'm trying to help, but nothing is working. Yeah, Or it's kind of like you're going through all of your keys and none of your keys are fitting the lock on the front door. Uh, it's

it's that kind of thing. And like without that compatibility, you can't actually have the immune system kick in. Now when it does work, essentially it kind of gloams on there and uh and renders the microbe inert unable to harm any any of the cells. So when a MicroB binners your body, the macroflages are on the case, they begin to attack microbes. They they hang out all over the body. The macroflages they're pretty much localized to whatever

area they are already in um. And then they also send out the alert to T cells, which start they kind of gravitate towards the lymph nodes. But T cells will come into play and uh, let the you know, really get the word out to say to the immune system, hey, here's what's going on, and here's how we need to respond help or T cells then emit the chemical signals that alert the immune system and B cells that produce anybody's that are compatible with that microbes andigen divide into

large plasma cells. Those mass produced the appropriate antibodies that bind with the energens, kind of gumming everything up, and it renders the antigen are the the microbe rather thank you from being able to infect a cell. And that's called humoral immune response or antibody response. But it ain't no joke, No, it's not humorous. It's just humoral. So then the killer T cells target all the cells that

have already been compromised. Uh. This is part of why you feel so bad when you're sick, apart from the symptoms that are specific to whatever pathogen you've been exposed to, and when your bodies I think it is sort of a general principle that a lot of the reasons you feel bad when you're sick are immune responses rather than the disease itself. A lot of it is because yeah, your body a will, you know, do several things in order to fight off diseases, and not all of them

make you feel hunky dory. In fact, most of them don't. Yeah, but but it's important because without that process then you would be much more vulnerable to these pathogens. Uh So, then once your teeth you don't want to pasiphist Imman, you definitely want you definitely want a good clings exactly. That offense is the best defense. Um. When your body's T and B cells have are able to render inert microbes faster than the microbes can reproduce, that means you're

beating the infection. You're winning in that that war. But that can take some time. Right, A particularly virulent pathogen might be able to replicate itself very quickly, and so you know, the initial stages might be pretty touching go,

depending upon the type of disease. Now, once your body fights off the disease, some of the T cells and B cells convert into memory cells, which retained this information about the disease and can rapidly produce the appropriate antibodies, which is why it's easier for you to fight off or even entirely resist future infections from the same strain.

But there's a big caveat here. Strains can sometimes mutate some, some mutate much more readily than others, Influenza being a big one, right, And when it mutates enough, it it's essentially like putting on a disguise and the antibodies don't recognize it anymore. And you have to go through the whole process all over again. So some diseases mutate so rapidly that like by common cold for example. That's that's why you can you can get the cold like four or five times in a row. Just because it's a

different version. Your body is completely unprepared to deal with this new version. It's why we can't vaccinate against it. I mean, there's there's hope that because often there's a little bit of the protein chain that remains the same from mutation to mutation that maybe one day we'll take advantage of that. But we'll talk about more of that stuff in part two. Yes, so with a vaccine, you know,

we've talked about that's the immune response to to a disease. Yes, So, so that is how all of that is how your immune system works. Vaccines mimic an infection, right. It's a purposeful introduction of of a pathogenic material. Essentially, they give your body a practice round. Yeah yeah, yeah. So you you introduce a weekend or dead strain of some sort of pathogen into a patient's bloodstream, which kicks the immune

system into gear. Uh. It responds just as it would with any other kind of infection, and the result is once that has run its course, your body is now able to produce the proper antibodies for that particular antigen eventually. Yeah. Yeah, it doesn't happen instantaneously. It takes a few weeks to build up this response. Right, So, if you've ever said I got a flu shot and then like a week and a half later ahead the flu, that flu shot gave me the flu, probably not. In fact, almost definitely not.

But the problem is that when you get that vaccination, because it takes time for your body to produce the appropriate antibodies in quantities that can make you immune, you're still vulnerable. So you could still catch the flu from

your buddy who happens to already have it. So so don't lesson here is that if you get the flu shot, don't go out and start licking door knobs and the house of someone who has the flu, right, yeah, I always always, I mean, maybe don't lick people's door knobs anyway, because I gotta stretch of time in the year that I have a strict no door knob licking policy, and

the outside of that, it's you know, flexible rules. Sure, but you still want to participate in your influenza cuddle puddles and yeah, yeah, so so just be careful for a few weeks after you get a vaccine, as all is all we're saying, right, And this is also why, like, if you're going to travel, you want to make sure you schedule the vaccinations for what, you know, if you're going to travel someplace that has particular diseases prevalent in

that area, you want to schedule your vaccinations well ahead of time before you actually you know, not the day before you get on the plane. Um, that might not be a great idea. Okay, So earlier you mentioned that there are lots of different types of diseases that we can vaccinate against, so it seems logical to assume that there are lots of different types of vaccines to deal

with the different types of diseases. There are, in fact lots of different types of vaccines to deal with different diseases, and some of them again, it's one of those things where, through through very careful experimentation, we were able to determine which version works best for any particular pathogen. And some of these also can be used in conjunction with one another, depending upon how you're trying, you know what diseases you're

trying to prevent. Um Now, I've always wondered why they can't just in ject some of that antibacterial soap or listering into you when you're getting sick. Do you also wonder why that you can't just drink anti freeze when it gets cold. Yeah, that's a good question to the Toxicity is still a thing, Joe. Toxicity is something that

we can't just just ignore. Okay, well you can't do that. Well, we gotta go with this this thing we've talked about earlier where they put some of these things that are going to harm you in your body for a practice round. Now they might be alive or they might be dead. Right, Yeah, so you're your first time. Sub type of vaccine would

be live attenuated vaccines attenuated meaning weekend exactly. And this would have you know, a live virus or some weekend strain of bacteria, depending upon what type of vaccine you're talking about, Uh, that you would then introduce to a patient before an uninfected person. Yes, that's a better way of putting it. The Yeah, I mean, I guess you're technically a patients as you walked through the door, but

uninfected person is much more accurate. So, but this sounds like it depends on the fact that you do have a fully functioning immune system, right, Yeah, you don't want to you don't want to give the sort of treatment to someone who has a compromised immune system because it will mean that there's still the possibility the virus could or bacterial infection could take hold and cause really severe

medical complications. Because it depends this, this system depends upon your all of your immune cells being up and ready to go. Yeah, yeah, because otherwise you can't develop the immunity. And in fact, I should say most or at least several vaccines require multiple doses over time in order for you to actually get to the level of immunity. Uh, many of them, Like a one shot is not enough

to have lifelong immunity. Some of them, there are, yeah, and and and some some some pathogens are too virulent to risk exposing that much of of a of the pathogen at a single time. Very good point. Yeah, yeah, exactly. And some are so virulent that you can't go with the live attenuated vaccine yeah yeah, And in that case you can use inactivated vaccines, which sounds like the vaccine itself is inactive. That's not what it means. Inactivated vaccines

used dead or inactivated viruses or bacteria. Then there's a toxoid vaccines, which sounds like it comes from trauma films but doesn't. Toxoid vaccines are used to treat bacterial diseases that produce toxins. So the vaccines themselves contain a weakened version of those toxins, and those are called toxoids. So when the body's immune system encounters the toxoids, it learns how to fight off the actual toxins. It's kind of

like building up an immunity to iokaine powder over. So that way, when the zini comes to you and gives you a mind game, you can choose whichever you know, whichever, it doesn't matter. Yeah, you can put you can put the syphilis in both kinds, that's right. Then you have subunit vac scenes. This is where a vaccine is sublet to another vaccine. Actually, no, that's not true. Subunit vaccines contain just bits of a virus or bacteria. Uh, it doesn't need to have an entire organism. Yeah, or or

virus is a little common. Yeah, but then I thought, Okay, it doesn't need to have I mean, virus is such a tricky thing, man, we could do a full In fact that we have talked about viruses a lot in this in this podcast. They're fascinating. But yes, you you need to have some part of the micro but you don't need the whole thing. Um. By limiting that pathogenic material to just the bits you need for the body to build up an immunity, you reduce the possibility of

really severe side effects. You're probably still going to have some because it's your immune system kicking in. And again, like we've said before, a lot of your symptoms are really your immune system reacting, not necessarily the pathogen itself. Um. Then you have conjugate vaccines. That's right. These are vaccines that have uh well it's this's weird, right. Conjugate vaccines are all about kind of fooling your immune system into

fighting the the pathogen you want them to fight. Uh. You use this to protect against bacteria that have antigens that are coded by something called polysaccharides, is like a sugar like coating. So the sugar like coding on the antigen disguises the antigen, so your immune system doesn't see it. Yeah. Yeah, So so that one of your when one of your T cells bumps up against one of these invading cells and goes like, hey, what are you? Are you chill?

Are you not chill? It doesn't find any of those antigens that would say, oh, I'm not chill, yeah this or even I'm not okay, right exactly, Yeah, that that this invading microbe, it's like it has an identifying badge that's turned the other way around, and the T cells just like, oh, you're probably fine and exactly So, conjugate vaccines connect polysaccharide two antigens so that the immune system recognizes that these are in fact foreign microbes that need

to be fought off. UM. And it's uh an interesting approach, right, it's linking the the idea of this particular polysaccharide represents this particular type of of microbe, and it's a little more indirect than some of the other methods we're talking about UM, which is pretty awesome. So we're going to conclude this episode by talking about some of the diseases that people have developed vaccines for. This isn't necessarily a completely exhaustive list, but it's pretty pretty decent sized list

of diseases for which we have vaccines. Smallpox the thing that we started talking about, Uh, that's a big one. It has been eradicated through vaccination. People don't get smallpox anymore. It's gone. And now the question is should we preserve tiny samples of it or destroy them? So, you know, we we we assume that it seems to be dead in the wild. We've got some samples of it in labs around the world. Should those labs keep them or not?

I think there are good cases to be made on both sides, Like the keeping it could help us develop protections in case it were to ever resurge in the wild. But then again on the other hand, like if yeah, if you're just keeping around, you don't you don't want the stand, right Stephen King's the stand to break out? Because that's a long book. No, that's not why. But anyway,

Also polio, we talked about that briefly. That's a viral infection that is close to being eradicated through vaccination, though they're still limited outbreaks in different parts of the world. And then here are all the not all, but here's a list of some of the vaccines we have for bacterial infections. That would include anthrax hib or hib diphtheria, uh nina, cockle disease like meningitis, whooping cough also known as pertussis uh new mccockle diseases. That's the cause of

bacterial pneumonia, not viral pneumonia, tetanus, and typhoid. The typhoid vaccine is not effective. It does create a resistance to typhoid, but you're not guaranteed to be immune to typhoid should you get that vaccine. Okay, that's the bacterial end. How about the viral end hep hepatitis A and B. We have vaccines for both of those. Shingles like we mentioned before, and chicken pox. The the again, the virus that causes shingles is also the virus that causes chicken pox, HPV, influenza,

although more on that in our next episode. Measles, momps, rhodavirus, rubella, yellow fever. All of those are viral infections for which we have vaccines. So it's a really impressive. Yeah, there's some big names that are on that list, but but that's that's amazing and it shows that we've come a long way. Yeah, like goteine humanity like these are. It's it's hard to imagine in in this day and age,

the amount of just disastrous tragedy that these diseases caused. Yeah, yeah, it's like every year, Like like the fact that that people our age have never had to worry about smallpox. It's it's hard to get across how huge that is when you're talking about disease that has been a scourge on humanity pretty much the entire history that we had civilized humans. So that's a big deal. And especially is more and more of us live in urban centers and and live within easy infection range of a lot of

other people. Sure, and of course also the population growth in places where you have other pathogenic vectors at play. Obviously, it also depends upon where you live in the sense of your access to vaccines. That's something that we'll talk about more in our second an episode. But this really was all about setting that foundation that understanding to realize, Wow, vaccines are pretty awesome and the future is going to be super interesting, fascinating really uh, and we're gonna talk

more about that in our next episode. So I guess I'm gonna have to give everyone a reminder. If you have suggestions for future episodes of forward Thinking, or you've got questions something that we didn't cover that maybe you would like to hear more about, send them to us. Our email address is f W Thinking at how Stuff Works dot com, or you can always drop us a line on Twitter or Facebook. If you search on Facebook for FW thinking will pop right up. You can leave

us a message we are FW thinking on Twitter. You can just tweet us there and we will talk to you again about vaccines really soon. For more on this topic in the future of technology, visit forward Thinking dot Com. Problem brought to you by Toyota Let's Go Places