I have been thinking about the way we talk to people who do not believe in vaccination. We usually begin with the vaccine. We tell them how effective it is, quote studies, explain the risks and point to what happened to disease rates after vaccines were introduced.
When that does not persuade, frustration sets in. Before long, one side is talking about ignorance and misinformation while the other is talking about freedom, government and pharmaceutical companies.
Perhaps we are starting in the wrong place. Suppose instead that we started with something on which almost everyone can agree: the human body is astonishingly good at looking after itself.
Cut your finger and, most of the time, you do not have to tell your body what to do. Blood clots, new tissue forms and the wound closes. Break a bone and a doctor can line it up and stabilize it, but the doctor does not actually knit the bone back together. Your body does that. Catch an infection and an immensely complicated defence system goes to work without waiting for instructions from you. Fever, inflammation, antibodies and specialized immune cells are part of a biological system that existed long before there were hospitals, pharmaceutical companies or public-health departments.
So, someone who begins with faith in the body’s ability to protect and repair itself is not beginning with nonsense. That person is beginning with one of the great facts of human existence. And I think acknowledging that matters enormously if we actually want to have a conversation about vaccines rather than win an argument about them.
The body really does learn
There is another intuition among people skeptical of vaccination that deserves to be taken seriously. If we encounter an infectious disease and recover, our bodies can sometimes remember it. The next encounter may be handled differently because the immune system has learned something from the first. Natural immunity is not an invention of people who distrust vaccines. It is real biology.
That can lead to a perfectly understandable question. If my body’s own immune system can learn to protect me, why should I interfere with that natural process?
The surprising answer is that vaccination does not replace that process. Vaccination depends on it. A vaccine cannot manufacture an immune system for you, stand guard inside your body or personally fight every virus or bacterium you encounter. Your body still has to do the work. What vaccination can do is give that extraordinary biological defence system some useful information before it encounters the full danger.
This changes the way we think about the word natural
We sometimes imagine natural immunity on one side and artificial vaccination on the other, as though we must choose between trusting the body and trusting medicine. But vaccination works only because natural immunity exists. Medicine discovered something the body was already capable of doing and found a way to enlist that capacity.
The vaccine is not the defence system. You are.
Preparing a healthy person for something that may never happen
There is nevertheless something genuinely unusual about vaccination. Medicine normally enters the picture after something has gone wrong. My knee hurts, so I see a doctor. I have an infection, so I take medicine. I break my arm, so somebody sets it. Vaccination reverses the sequence. A perfectly healthy person receives a medical intervention today because something might happen tomorrow.
It is understandable that this makes some people uneasy. We are doing something to a healthy body to prevent an illness that the person may never get.
But outside medicine we make this kind of decision constantly. We install smoke detectors in houses that are not burning. We put seat belts into cars that are not crashing. We teach children to swim before they fall into deep water. None of these things means we expect disaster. We prepare because we cannot know whether it will happen.
Vaccination adds one remarkable feature: the preparation takes place partly inside the body itself. We are not simply erecting an external barrier against danger. We are giving the body’s own defence system an opportunity to prepare for something it may later encounter.
That seems to me a very different way of describing vaccination from the language of putting a foreign substance into a healthy body. Both descriptions refer to something that is physically happening, but the first tells us much more about why we are doing it.
But isn’t some adversity good for us?
There is a deeper intuition here that I find particularly interesting because there is considerable truth in it. Human beings are not strengthened by eliminating every challenge from their lives. Muscles need resistance. Bones need loading. Children need to encounter difficulties. The immune system was not designed to exist in a completely sterile world. Living things develop in conversation with their environments.
We could call this resistance, adaptation or even antifragility. Whatever word we use, the underlying idea is familiar: protecting a living thing from every conceivable challenge does not necessarily make it stronger.
The mistake comes only if we assume that because some adversity strengthens us, greater adversity must strengthen us more. We strengthen bones by making them bear weight; we do not strengthen them by breaking them. We strengthen the cardiovascular system through exercise; a heart attack is not therefore an exceptionally vigorous workout. The useful challenge has to be one from which the organism can learn and recover rather than one capable of overwhelming it.
Seen this way, vaccination need not be understood as an attempt to make human beings more fragile by shielding them from nature. It can be understood almost in the opposite way. It asks an adaptive biological system to adapt. Instead of insisting that the body learn only by enduring the full disease, we have discovered ways of giving the immune system a safer encounter with the information it needs.
That is not a repudiation of the body’s capacity for resilience. It is an ingenious use of it.
Taking risk seriously
None of this requires pretending that vaccines are incapable of causing harm. Medical interventions have risks. Vaccines can have adverse effects. Human institutions make mistakes. Pharmaceutical companies have commercial interests. Governments can communicate badly. Scientists can be wrong, and science changes its conclusions when better evidence arrives.
Acknowledging these things should not be regarded as surrendering to an anti-vaccine argument.
The useful question was never whether a vaccine has zero risk. Almost nothing worthwhile in medicine, or indeed in ordinary life, can pass that test. The relevant question is whether preparing the body through vaccination carries less risk than leaving it to encounter a particular disease without that preparation. The answer has to take account of the vaccine, the disease, the person and the circumstances. Being strongly in favour of vaccination does not require pretending that every vaccine decision for every person is identical.
This is also why I think simply telling a skeptical person to “trust the science” can be such an unsatisfactory response. Trust is not knowledge. It is what we sometimes have to extend to other people who possess knowledge we cannot independently reproduce. A better conversation explains what we know, how we know it, what we do not know and where uncertainty remains.
What we know from our own bodies
This brings the vaccine discussion into a larger question about how human beings discover things.
Personal experience is knowledge. If I take a medication and feel terrible afterward, something happened to me. If a parent watches a child become ill, that experience is real. It should be listened to, recorded and investigated rather than dismissed because it has not appeared in a medical journal.
Human beings learned an enormous amount about health this way long before randomized controlled trials existed. We watched what happened. We remembered. We compared one experience with another. We passed useful knowledge to the next generation. Modern science did not invent the human capacity to observe reality.
But every way of knowing has boundaries. I can know extraordinarily well what happened to me. My own body cannot tell me what happens to one person in 100,000. Nor can my experience alone tell me whether something that happened after a vaccination happened because of the vaccination. To answer questions like those, I need access to other people’s experience.
At its best, that is what medical research provides. It does not have to mean that individual experience is unimportant. It allows us to assemble thousands or millions of individual experiences and discover patterns that no single human being could possibly see.
The mistake is to force one kind of knowledge to do a job it cannot do. Personal experience can tell me things that a national database may miss. Population evidence can reveal things that my personal experience cannot possibly detect. We need both, and we need to understand what each can tell us.
The strange problem of something that never happened
Prevention creates an additional difficulty because successful prevention is almost invisible. If medicine treats an illness successfully, there is a story to tell: I was sick, I received treatment and I recovered. Successful vaccination frequently produces no story at all. I received the vaccine and went about my life.
Perhaps I would never have contracted the disease anyway. Perhaps I would have contracted it but experienced only a mild case. Perhaps the vaccine prevented a hospitalization that, in another version of my life, would have happened. I can never meet that other version of myself and compare notes.
A harmful event following vaccination is quite different. It happens to an identifiable human being at an identifiable time. It can be seen and remembered. The person whose serious illness was prevented is usually invisible precisely because nothing happened to that person.
This is not a defect in anybody’s reasoning. It is an inherent problem with understanding prevention. The event we can see naturally commands our attention; the event that never occurred cannot. Once again, this is why we sometimes need knowledge assembled across many people to see something that none of us can easily see in our own lives.
And then there is freedom
Someone can understand all of this and still say, “Fine. But it is my body and I should decide.”
That is a serious argument. But it is simply a different argument.
Whether vaccination works and whether government should compel vaccination are separate questions. We did ourselves no favour during COVID19 when the two became almost indistinguishable. A person can oppose vaccine mandates and nevertheless believe that vaccination is an extraordinarily useful medical technology. A person can support some public-health requirements while still asking perfectly sensible questions about the risks and benefits of a particular vaccine.
We do not have to settle the proper limits of state power before we can understand what an immune system does.
Indeed, separating these questions might lower the temperature considerably. Someone does not have to surrender personal autonomy as the price of understanding the medical case for vaccination. Nor does acknowledging bodily autonomy tell us whether a vaccine works.
Starting somewhere else
So perhaps the better conversation with someone deeply skeptical of vaccines does not begin by listing everything that person has misunderstood. Perhaps it begins by asking what that person already understands about the human body.
It heals itself. It adapts. It learns. It remembers. It responds to challenges. It possesses systems of defence more complicated than anything human beings could design from scratch.
Those are not anti-scientific beliefs. They are biology.
And then we can ask a different question:
What if vaccination is not a rejection of those abilities but one of the things human beings discovered we could ask those abilities to work with?
That possibility allows us to understand much of the intuition behind vaccine skepticism while remaining strongly in favour of vaccines. I do not have to choose between believing that nature is wise and medicine is wise. The relationship is much more interesting than that.
Medicine did not invent the immune system. It discovered something about how the immune system learns and remembers and then learned how to provide it with information before some of its most dangerous encounters.
That seems to me to fit a larger truth about discovery. We did not invent gravity when we learned to fly. We did not conquer the laws of nature when we built a bridge. We learned enough about them to work with them.
Vaccination belongs to that tradition.
Nature supplied the defence system. Human beings discovered one way of teaching it before the exam.
Perhaps if we began there, fewer conversations about vaccines would have to end with people shouting at one another about whether they trust science. We could start instead with something much closer to all of us: trust in the remarkable capacities of the human body itself.