“Natural immunity” is the trope du jour of the anti-vaccine world – they want us to believe that contracting a dangerous pathogen is somehow better than preventing that disease with a vaccine. Their pseudoscientific beliefs rely upon logical fallacies, a complete misunderstanding of how the immune system works, and a healthy dose of bad math.
In other words, the same old same old from our anti-vaxxer “friends.”
The purpose of this article is to discuss why natural immunity is a bogus concept when it comes to vaccines. I need to make one warning upfront – immunology is complicated and cannot be described in 1000 words or less. So, I’m going to do a lot of linking to good articles that describe various things about the immune system.
But here we go – hang on for some science.
The science of the immune system
Now comes the science part of the article. I, and others, always complain that the junk science world massively oversimplifies the mechanisms of the immune system. Simplifying complex science makes it easy to consume, but that does not make it better at all.
When I read that someone, generally an anti-vaxxer, claims that they’ve “done their research” about the immune system, I laugh. And very loudly. As I’ve written before, it takes thousands of hours of classwork, research, and publications to gain expertise on the immune system. Not a few minutes on Google.
For example, the vaccine deniers love to characterize the immune system as a one pathetic, weak, hardly functional little organ – which it is not. In fact, the immune system is a huge, complex, interrelated bunch of biomolecules, cells, tissues, and organs, usually all working in harmony. And it’s pretty resilient.
Let’s remember that the immune system of all higher organisms on the planet (mammals like humans, birds, even plants) have evolved over 4 billion years. And the more complex immune systems, like in all mammals, are in a constant war with pathogens, which becomes a natural selection to improving the immune system over those billions of years.
Unless you’re very young or suffer from a chronic disease that harms the immune system, it does a great job in dealing with all of the antigens someone encounters every single day of the year.
And when these pseudo-immunologists make some claim that something they do will fix or improve the immune system, the first question you should ask is – “where is that peer-reviewed, published, extraordinary evidence that supports your extraordinary claim.”
You don’t have to hold your breath, because they never have any extraordinary or even ordinary evidence.
Now, it’s time to get science-y and describe the immune system. Admittedly, I’m writing this not only to be informative but also to overwhelm the notion that the immune system is some simplistic entity within the body.
The immune system is made up of two basic parts – the innate immune system and the adaptive immune system. Let’s start with the innate system first, then examine the more complex adaptive immune system.

Doesn’t help the immune system. Photo by Element5 Digital on Unsplash.
The innate immune system
This part of the immune system includes an ability to prevent or detect foreign material, then eliminate it without an antigen- or pathogen-specific physiological response of the body. It is the body’s quick and initial general response to disease-causing organisms (pathogens) which invade our body.
The innate response works in one of two ways – first, it directly prevents an infection, such as the skin blocking bacteria from entering the bloodstream. And second, it delays the invasion sufficiently for the slower but more effective and selective adaptive Immune system (see below) to activate its response to the pathogens.
But the innate immune system isn’t a simple thing, it is extremely complex, consisting of:
- Anatomical barriers – These are actual physical barriers to pathogens. One of the best examples is the skin itself, which is impermeable to pathogens providing defenses like a solid wall. There are many other examples, such hairs in the nose, or mucous – all of which keep nasty pathogens out of our body.
- Inflammation – This response includes the symptoms we associate with inflammation – fever, swelling, increased blood flow, repair of damaged tissue, and removal of foreign and dead tissue.
- Complement System – This system consists of a group of biochemicals, produced by the liver, that helps or “complements” the ability of antibodies and phagocytic cells to clear pathogens from an organism. It is part of the immune system that is not adaptable and does not change over the course of an individual’s lifetime. However, it can be recruited and brought into action by the adaptive immune system. (To be clear, the complement system works in both the innate and adaptive immune systems.)
- Cells–Mostly white blood cells (WBC) are involved in the innate immune system:
- Mast Cells – A group of cells that mediate the inflammatory response. Although they are often associated with allergies, they are a critical part of the immune response.
- Phagocytes – Large cells that move like an amoeba. They “eat” other cells by surrounding them with their plasma membranes producing “bubbles” in which they can release enzymes safely without damaging other cells. They also have a “clean-up” role to remove the body’s dead and dying cells.
- Macrophages – Large phagocytic cells that efficiently consume multiple pathogens. Heavily motile and actively cross from the bloodstream into tissues to hunt down pathogens. They kill by manufacturing and releasing free-radical oxygen in a local area.
- Neutrophils/Eosinophils/Basophils – A group of similar cells that are the “first responders” to migrate to an inflammation site. They appear at the site of a wound within a few minutes of trauma.
- Natural Killer Cells – These cells recognize the body’s own cells that are infected by viruses or are cancerous. They then induce controlled cell death to halt the spread of the infected or cancerous cells. Recent research shows that Natural Killer Cells also play a role in the adaptive immune response.
- Dendritic Cells and Gamma/Delta T Cells – These are the bridge between the innate and adaptive systems and their main role is antigen presentation. They harvest antigenic proteins from damaged pathogens and present them to T-cells, which allows them to find and attack the pathogens.

A visual depiction of the innate immune system. Notice the complexity? Internet quacks and anti-vaxxers like you to believe it’s easy to boost the immune system – so where does that happen?
Because it comes up frequently, the innate immune system is mostly inherited, because it is non-specific. It doesn’t care if the pathogen is a cold or a strange parasite, it deals with them in a non-specific manner. In a sense, the innate immune system provides us with “natural immunity” because we really don’t have much control over it.
But we all know that that isn’t what the anti-vaxxers mean.
The adaptive immune system
The dendritic cells, from the innate immune system, activate the body’s adaptive (or acquired) immune system. The adaptive immune system is composed of highly specialized, systemic cells and processes that eliminate or prevent pathogen growth.
The adaptive immune system employs pathogen-specific receptors which are “acquired” during the lifetime of the organism (whereas in innate immunity, pathogen-specific receptors are already encoded in the germline). The acquired response is said to be “adaptive” because it prepares the body’s immune system for future pathogenic attacks.
In some cases, the acquired immune response can be maladaptive when it results in autoimmunity. This is also why a lot of immunologists (and those of us with significant immunology education) cringe when someone says “boost the immune system.” If we really could in a general, non-specific manner, we’d be destroying ourselves. As I said, the immune system is well-balanced to protect us from pathogens, messing around with it, without a high degree of specificity (like vaccines) is dangerous.
But back to that immune system.
Antibodies, produced by B-lymphocyte cells, are the main weapon of the body’s immune system to battle pathogens. It is a larger response than innate immunity and once sensitized to an antigen, the adaptive immune system often fights off diseases even before we can present with symptoms of a disease.
Immunizations introduce the pathogen’s antigen (without inducing pathogenicity) to the adaptive immune system so that it can form those pathogen-specific receptors and, thereby, are able to quickly and efficiently respond to an attack by a pathogen, before it harms the host.
In other words, vaccines induce the antibody response to a pathogen without causing the host, that is you, to contract the disease itself.
And we’re back to science – there are three types of cells involved in the adaptive immune response:
- T – Lymphocytes (also known as T-cell) – The main role of this cell is to recognize other cells that are infected by viruses and trigger the apoptotic pathway, a specific mechanism that destroys the cell and its viral contamination. Since viruses only replicate inside cells by hijacking the cell’s manufacturing process, this apoptosis kills the virus (and the host cell) and phagocytes swoop in to consume the destroyed cell debris and digest the contents – it is an efficient and powerful method to destroy pathogenic viruses. The antigen of the viral cell is recognized by surface antibodies on the T-Lymphocyte, which activate the lymphocyte. There are also helper T-cells whose role is control and organization of the apoptosis response to the infected cells.
- B – Lymphocytes – The main role of these cells is to produce humoral (free-floating) antibodies that recognize pathogens and mark them for destruction by other cells. It’s almost like they float around and paint red x’s on the pathogens so that the rest of the immune system can easily find them. This process occurs by activating the complement system and by causing the pathogen to become “sticky” but only with other pathogens. This causes them to clump together and make them easier to kill by T-cells. Again, this is just a gorgeous, and very complex, method to destroy pathogens.
- Memory Cells – After an infection has passed (and most of the T-cells and B-cells have died), a few do remain in circulation to remember the antigens of the pathogens who attacked. In future infections, these are rapidly activated to produce a humoral response which quickly destroys any new infections even before they produce any symptoms. There are two types of these cells – Memory B cells, which, produce the antibodies that recognize the pathogens, and Memory T cells, which remember the viral antigens that infect cells.
And there’s actually more. In infants, there is a version of the immune system called passive immunity. Certain classes of antibodies can cross the placental barrier and can be absorbed through milk particularly the colostrum (first milk).
However, the baby’s immune system does not develop its own adaptive immune response from these antibodies, and eventually must be presented with one of the millions of antigens it inhales every day to form its own adaptive immune system.
This passive immune system gives the newborn baby the same range of protection as the mother, although, because there is not an infinite supply of antibodies in the baby, it is not as robust an effect as a mature immune system. Moreover, this passive only lasts a few months.
As opposed to the innate immune system, the adaptive immune system is not heritable. A parent that becomes immune to measles (either from vaccines or the disease) does not pass that on to the child, except, as we mentioned, with the temporary passive immunity for an infant.
I know, that was a lot of science. Yet, I gave you like the first 10 minutes of two years of graduate-level immunology courses.
That being said, the innate and adaptive immune systems are pretty freaking awesome, but it’s not perfect. Like I mentioned above, pathogens have evolved over billions of years in response to other organisms’ immune systems, so they have developed all kinds of tricks to avoid being destroyed by the human immune system.
The influenza virus is one of the experts of quickly evolving to change itself almost annually to avoid the immune system. HPV (human papillomavirus) avoids the immune system by actually integrating itself into human DNA.
Despite what I’ve written here, we still haven’t discussed natural immunity versus vaccines.
Natural immunity – THE logical fallacy
Basically, the anti-vaccine zealots love to state that natural immunity, from any disease, is not only safer (it isn’t) but provides better immunity (it doesn’t) than vaccine-induced adaptive immunity. This is based on very little actual science, of course.
We’ll get to the science in a moment, but I wanted to start with the logical fallacy that underlies this belief of the anti-vax world. It’s the appeal to nature, which basically states that “natural” is always better than “unnatural”. It assumes that “nature” is good, so natural immunity is better than vaccines, which are “unnatural.”
I never have understood why people buy into this logical fallacy. First, natural is not always better. Snakes and spiders have venom that can cause serious harm or death. There are numerous “natural” organisms that contain chemicals which substantially increase the risk of cancer.
Second, the point of vaccines is to induce immunity without the dangers of concomitant with “natural immunity,” which means exposure to dangerous and, often, deadly pathogens.
Just visit 19th-century cemeteries – you can see family after family with children buried before they turned five because of “natural immunity.”

Watch out, dangerous natural immunity. Photo by Raúl Nájera on Unsplash.
Natural immunity – the dangers
I’ve written this several times, but it bears repeating again and again. We don’t vaccinate children because Big Pharma wants to make a ton of money (not true) or the CDC has secrets patents that make them a ton of money (not true) – we immunize with vaccines to protect children and adults from disabling and deadly diseases.
The human papillomavirus (HPV) is linked to over 40,000 cancer cases every year in just the USA alone. These are nasty, deadly cancers – anal, cervical, penile, oropharyngeal, vaginal, and several other cancers are linked to some of the more prevalent subtypes of the virus. And we have a vaccine to prevent it.
Measles is not a benign disease. According to the CDC, some of the many measles complications are:
- About 30% of measles cases develop one or more complications.
- Pneumonia, which is the complication that is most often the cause of death in young children.
- Ear infections occur in about 1 in 10 measles cases and permanent loss of hearing can result.
- Diarrhea is reported in about 8% of cases.
- As many as 1 out of every 20 children with measles gets pneumonia.
- About 1 child in every 1,000 who get measles will develop encephalitis, an inflammation of the brain that can lead to convulsions, deafness, and other long-term neurological deficits.
- A measles infection can result in short- and long-term immune system dysfunction which can leave the child susceptible to other diseases early in life (which is in direct opposition of claims by anti-vaccine activists that it helps “boost” the immune system. In other words, natural immunity to measles can actually harm the immune system long-term.
- About 1-2 children, out of 1000 who contract measles, may develop subacute sclerosing panencephalitis (SSPE), a rare chronic, progressive encephalitis that affects primarily children and young adults– it is caused by a persistent infection of the measles virus. The disease starts with measles infection, usually before the age of 2 years, followed by approximately 6-15 asymptomatic years. Some researchers think the asymptomatic period is around 5-8 years after the initial disease. Gradually, the disease progresses with psychological and neurological deterioration, which can include personality changes, seizures, and coma. It is always ultimately fatal.
- And sadly, for every 1,000 children who get measles, 1 or 2 will die from it.
Contracting chickenpox is annoying and potentially dangerous short-term. Unfortunately, the chickenpox virus, Varicella zoster, has this nasty ability to hide from the immune system in certain nerve bundles. Then, for unknown reasons, a few years, even decades later, the virus re-emerges from its hiding place to cause shingles, a painful and dangerous disease. Getting “natural immunity” to chickenpox only means you’re condemning the individual to shingles in later life. Of course, there’s the shingles vaccine to prevent it.
“Natural immunity” to whooping cough (pertussis) means that your children go through weeks of suffering just to make some illogical point. David Gorski, MD, wrote about this a few years ago:
Nowhere is that more clearly demonstrated than in this sad case, where “natural immunity” was felt to be more important that medical care. I have no doubt that Dexter (a naturopath whose three children contracting pertuss) cares deeply for her children. But all of the suffering that Dexter’s children endured was likely completely preventable, had they been vaccinated.
Moreover, had she acted quickly, she could have limited the infection to her oldest child, lessening her suffering, and reducing the very real risk to her other children. But instead, they were all infected. They cried, they coughed, they vomited and they even turned purple. And for what purpose? I have to admit, I’m at a loss to understand this.
Writing this post has left me frustrated and sad for three small children who were denied a chance to avoid a horrible illness and months of misery. I guess it simply illustrates how strongly wedded some are to the naturopathic worldview. One in which adherence to a prescientific philosophy seems to trump the obvious suffering of your own children.
I could write a long article about the consequences of chickenpox, diphtheria, polio, rotavirus, influenza, and all of the other vaccine-preventable diseases. And in each case “natural immunity” is far more dangerous than immunization by vaccines!
Unfortunately, the effectiveness of vaccines is blurred by most individual’s inability to analyze risk. For example, HPV doesn’t cause cancer in 100% of cases (the same with tobacco smoking) – and if it does cause cancer it may not be for decades. So, we may give a teen the HPV vaccine today, and it prevents cervical or oropharyngeal cancer 20 years from now. The effect is so far down the road, it’s hard to comprehend.
Moreover, vaccines are a victim of their own success. We don’t see measles epidemics any more – well, we are, but that’s thanks to anti-vaxxers. But back when I was a child, no parents wanted their kids to get “natural immunity” from an outbreak sweeping through the schools. Because too many children died from it.
The same with polio, chickenpox, rubella, and many of the diseases that we just don’t see anymore. We don’t have a cultural memory of keeping our children away from swimming pools because of polio. We don’t have that memory of keeping our kids away from school.
And one more thing – despite the advances in medicine over the past 50 years, polio cannot be “cured.” Measles cannot be “cured.” You get those diseases, and that’s it, the best doctors can do is to treat secondary issues and keep the child from succumbing to side effects of the disease.
But issues like SSPE, which results from measles, aren’t apparent for 5 years, more or less.

Obligatory cute puppy photo – probably has vaccine immunity to several diseases. Good doggy. Photo by Nikolai Chernichenko on Unsplash.
Natural immunity – myths
The vaccine-denying natural immunity believers like to claim that the infection provides a lifetime of immunity. OK, here they have a tincture of truth, surrounded by a mountain of facts that establish that they have no clue about science.
- Natural immunity is not perfect – there is no 100% guarantee of immunity based on a lot of factors.
- Natural immunity does not always last longer than vaccines – remember, vaccines work on the principle that it induces the immune system to remember a few key antigens from the virus or bacteria (or in some cases, the bacterial toxin). In most cases, the vaccination lasts for many decades, and a simple booster can make it last for many more decades. And again, depending on a lot of factors, natural infections may only induce short-term adaptive immunity (it happens a lot).
- Natural immunity does not make a child healthier, like that debunked claim that contracting measles prevents cancer.
- Some pathogens mutate every year, like influenza. If you get natural immunity from the flu in 2019, that’s not going to help you much in 2020.
- Natural immunity is not inherited from either parent, either through genes or through breastmilk. Stop that nonsense.
- Natural immunity is not safe – we’ve established that, but it bears repeating.
Summary
Natural immunity is one of the favorites of the anti-vaccine community. Parents have set up “measles parties” to infect their kids with a dangerous disease (I don’t know why this isn’t child abuse, but it should be). It doesn’t work any better than vaccines, and it puts the child in harm’s way. Stop that ignorant bovine feces of an idea.
Finally, we have got to get over this idea that “natural” is better than alternatives because of reasons. Evolution did not happen because it is some benevolent, magical system to make humans healthier and happier. Evolution, which gave us our immune system, arose out of random mutations and natural selection (in this case, natural has a different meaning).
Humans “naturally” evolved intellect and reasoning, so we could develop vaccines that prevent diseases but training the immune system to do its job better and faster. But the privileged few who hate vaccines will get into their gas-guzzling SUV, drive 2 blocks to get their GMO-free, organic foods to make their anti-cancer blueberry-kale smoothies, then drive another two blocks to make sure vaccines are given to any kids in their Waldorf pseudoscience school.
I guess with all the carbon they emit from their SUV, climate change will destroy us before vaccine-preventable diseases do. That’s another story for another time.
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