12/03/2025
Well done explanation! Vaccinate on time, every time. Train that immune system to recognize immediately the invading microbe and mount a crushing response!
The Antigen Exposure Reality - Why worrying about over-exposure to vaccine antigens at the rates used is not an issue of concern:
One of the most persistent myths in the anti-vaccine playbook is that the childhood vaccination schedule has “too many vaccines, too soon” and that we’re somehow “overloading” children’s immune systems.
Let’s me put this claim to rest with some actual numbers.
The entire modern childhood vaccination schedule exposes a baby to fewer than 200 total antigens across all shots combined from birth through to age two. Anti-vaxxers look at that number and panic. “Too many antigens! Too much, too soon, they’re overloading a child’s immune system!”
Here’s what they’re actually missing: that baby’s immune system is already processing billions of antigens every single day just from being alive.
Your gut microbiome alone exposes you to somewhere between 1 million to 1 billion different antigens every single day. That’s 10^6 to 10^9 antigenic structures from the bacteria living in your intestines. And yes, babies have this too - their microbiome starts colonising from birth.
But wait, there’s more. Every time you breathe, you’re inhaling microbes. We take about 20 breaths per minute, nearly 30,000 breaths per day, inhaling roughly 15,000 litres of air and depending on the particular environment you’re in. Every single breath can contain around 10,000 bacteria and 5,000 viruses. That adds up to between 100 million and 150 million virus particles per day just from breathing. Each one of those microbes carries between 100 million to 1 trillion unique antigenic structures.
Your skin is exposed to between 10,000 to 100 million antigenic structures per day through touch and contact with surfaces. A baby grabbing toys, crawling on floors, putting their hands in their mouth - they’re getting constant antigenic exposure.
So when someone tells you they’re worried about giving a baby “too many vaccines, too soon,” they’re fretting about 200 antigens spread over two years while that same baby is already processing billions of antigens every single day.
Actually, it’s even more absurd than that. The childhood vaccine schedule used to contain far MORE antigens. In the 1960s, children received vaccines against fewer diseases, but those vaccines contained about 3,000 bacterial and viral antigens. Today’s vaccines are far more refined and purified. We now vaccinate against more diseases but with fewer than 200 total antigens. Modern vaccine technology has made them more effective with far less antigenic load.
The “too many, too soon” argument completely falls apart when you understand the scale. From this perspective it’s like worrying that adding a teaspoon of water to the ocean might cause flooding.
Thats not to say the exposure via vaccines can’t be detrimental, but that’s why we research and test in the first place, to ensure the dose and adverse event rate are all well understood.
But here’s the critical part that anti-vaxxers never acknowledge: during an epidemic or pandemic, or even day to day exposure your child is going to get exposed to that pathogen and those antigens anyway. The question isn’t “if” - it’s “how.”
You have two options:
Option 1: Let your child encounter the full-strength, dangerous version of the virus with all its complications - the risk of severe disease, hospitalisation, death, and long-term damage.
Or Option 2: Give your child a safe, attenuated or carefully designed vaccine that trains their immune system against the pathogen without the risk of actual disease.
Take measles, for example. The actual measles virus infects your child with a pathogen that can cause encephalitis, pneumonia, and death. It also causes immune amnesia that can last years, wiping out your child’s protection against other diseases. The measles vaccine? It’s a weakened version that gives your child immunity without any of those risks.
Or look at the COVID mRNA vaccines. These don’t even contain the virus at all - just instructions for your cells to temporarily make the spike protein, which your immune system then learns to recognize and destroy. You get immunity without ever being exposed to the actual virus and all its complications. And yes we should acknowledge there can be vaccine induced complications - but these risks are minuscule compared to the virus.
The immune system evolved to handle constant bombardment from the microbial world. Your body produces approximately 30 million unique antibodies - different shapes that can recognise almost any molecular pattern. This isn’t some fragile system that gets overwhelmed by a couple of vaccines. It’s a sophisticated defense mechanism designed to deal with an unimaginable diversity of threats every minute of every day.
Your immune system isn’t sitting idle between infections. It’s under constant assault from the microbial world around you and inside you. It’s always working, always sampling, always ready. A vaccine isn’t adding a burden - it’s giving your immune system practice with a specific, harmless target so it can respond faster when the real threat appears.
The “too many, too soon” crowd would have you believe that we should space out vaccines, delay them, or skip them entirely. But during that delay, your child is still being exposed to billions of antigens daily from their environment. And worse, they’re vulnerable to the actual dangerous pathogens that vaccines protect against.
Think about what happened during the COVID pandemic. Parents who had been delaying or refusing vaccines suddenly had unvaccinated children exposed to a novel virus their immune systems had never seen before. Those children were at higher risk of severe disease, hospitalisation, and death compared to vaccinated children. The “wait and see” approach didn’t protect them - it left them vulnerable.
The immune system can absolutely handle the vaccine schedule. It’s handling far more every day from just living in the world. What it can’t always handle is the full-force assault of a dangerous pathogen when it has no preparation, no prior training, no antibodies ready to respond.
So the next time someone tells you they don’t want vaccines because of “all those antigens” or because it’s “too much, too soon,” remind them of the reality: their child is already exposed to billions of antigens daily. The difference is that vaccines give immunity without the risk of actual disease. That’s not an overload - that’s simple and smart biology using the safest possible route to protection.
In an epidemic or pandemic, your child will be exposed. You can’t avoid that. But you can choose whether that exposure is to a safe vaccine or to a dangerous pathogen. One builds immunity safely. The other is a gamble with your child’s life.
The evidence couldn’t be clearer: get vaccinated and boosted.
REFERENCES:
1. Offit PA, et al. Addressing parents’ concerns: do multiple vaccines overwhelm or weaken the infant’s immune system? Pediatrics. 2002;109(1):124-129. https://publications.aap.org/pediatrics/article/109/1/124/64774
2. Dickson RP, et al. Bacterial topography of the healthy human lower respiratory tract. mBio. 2017;8(1):e02287-16. https://mbio.asm.org/content/8/1/e02287-16
3. Sender R, Fuchs S, Milo R. Revised estimates for the number of human and bacteria cells in the body. PLoS Biol. 2016;14(8):e1002533. https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002533
4. Hilleman MR. Vaccines in historic evolution and perspective: a narrative of vaccine discoveries. Vaccine. 2000;18(15):1436-1447. https://www.sciencedirect.com/science/article/pii/S0264410X99004343
5. Mina MJ, et al. Measles virus infection diminishes preexisting antibodies that offer protection from other pathogens. Science. 2019;366(6465):599-606. https://www.science.org/doi/10.1126/science.aay6485
