One of the most common myths about immunizations, is that pediatricians are using a vaccine schedule that is far too aggressive; that we are giving kids too many vaccines all at once at it is BAD for them. Well, I have some great news for concerned parents. That idea is not true! In fact, not following the schedule or "spreading out" the vaccines, can do more harm than good.
When I took my son to his two month checkup, and even though I already knew it was safe and the best thing for my child, I was horrified as they came at my baby with so many needles. I absolutely understand the trepidation parents have about giving their children multiple vaccinations at once. Before my son was born I talked to my pediatrician at length about the vaccine schedule and I also had numerous in-depth conversations with my PhD advisor, who just happened to be a world-renowned MD expert on vaccine development, vaccine components, and the human immunological responses to them. I learned so much during that time, but I was lucky to have such resources. Most parents don't have easy access to those kinds of experts so I'm here to save you some time and hopefully some stress.
Let's start at the beginning. The immune system is made of cells and proteins that defend us against infections. When we encounter bacteria, viruses, fungi, parasites, or all of the above found in tenth grade locker rooms, our immune cells get to work. Some immune cells fight the baddies directly and others produce antibodies because they don't like to get their hands dirty. The process of making antibodies allows our bodies to remember the baddies so next time they can react even faster. Fast enough to save our lives, in fact. And by the way, this is what vaccines do for us. They prime us safely, without having to get sick, so that we won't get deathly ill from a germ we are exposed to in the wild (i.e., everyday life).
Here's something most people don't realize, the immune system of a healthy infant is ready to go. B and T cells are present in developing babies at 14 weeks! By then they also express a myriad of antigen-specific receptors - antigens are the proteins and polysaccharides from pathogens that are recognized by immune cells. If your immune cells have the receptors for these antigens, then you can mount an immune response. This stuff happens early! However, babies can't make antibodies to pathogens they've never been exposed to. To circumvent this, moms pass antibodies to their babies in the womb, through the placenta during the last three months of pregnancy. This is how important vaccines are: your kids get the first ones before they are born! This is great and really helps keep our kids healthy when they are newborn. The baby will only be as immunologically protected as the mother is though, so it's a great reason not to skip on your vaccines. This is also one of the reasons why preemies have it tougher - they didn't finish their in utero vaccine schedule. During breastfeeding, more antibodies are transferred, but this passive immunization doesn't last. And now they are out in the world and may be exposed to some very deadly pathogens, so how do we protect them?
Praise the Lord and Pass the Ammunition - in this case Vaccines! We are lucky enough to live in a time of effective and safe - yes safe - vaccines. We don't have to blow bits of dried pox scabs up our child's nose and hope they live (variolation). We can go to the pediatrician and let the nice, highly trained nurse give our child a shot - with a tiny needle. That we can do this is amazing! That parents choose not to because people with no training or education fear monger around the clock, is horrific.
So why isn't it harmful to give your child four vaccines at once? The simple truth is that doing so does not, in fact, over tax their immune system. When our relationship with vaccines was still in the honeymoon phase - 100 years ago, 40 years ago, they contained a ton of antigens because scientists didn't know exactly which ones provided protection and they wanted to cover their bases. Even those vaccines did not overtax the immune system. They might have evoked an immune response that could be detected - e.g., a fever, but they didn't short circuit the immune system. In fact, only a fraction of your child's immune capacity is put to work responding to vaccines, even with thousands of antigens. Today, we give our children more vaccines - because we love how preventing terrible diseases lets our kids grow into adults - but each one is now streamlined. Scientists have been able to identify the specific antigens truly necessary for immunity and use only those in vaccines. So now it takes an even smaller fraction of your child's immune capacity to respond to their multiple vaccines. Furthermore, the capacity of the immune response is not static - it's regenerated all the time. As cells are put to work, more cells are made. Our bodies are really something fantastic. Check out Table 2 in this very well-researched article. It details the number of antigens in vaccines through the short history of these amazing immune boosters. It also provides all the info you might ever like to know about why multiple vaccines are safe - with references. You see, scientists take our concerns as parents seriously and are trying to help.
Now we understand that our children are fully capable of handling the small number of antigens found in even multiple vaccines. But surely it wouldn't hurt my child if I decided to spread out the vaccines because I'd be more comfortable with that, would it? Well, actually it could. On a couple of levels. Most importantly, the reason they get vaccinated multiple times for the same disease is because researchers, through extensive, exhaustive studies - that don't pay well by they way, learned that to protect our children best, with the fewest side effects, we give small doses a few times. The booster shots are required for full immunity to develop and if the shots are not given within the time frame required, your child won't be protected. In addition, the longer a child goes without protection, the greater the chances of getting really sick upon exposure to a nasty pathogen.
There's another thing to think about here too. A child getting four vaccines at once, hates it. But it's done and over. If you spread out all the shots, you'd have to take your child to the doctor's office like once a month for a year and each time they'd get a shot or two. This could lead to a serious fear of doctors and vaccines. Not something we really want to cultivate in our children, right? Nah. We want what's best for them and fearing doctors and vaccines isn't what's best.
And the truth is, that being afraid of vaccines is not necessary and doesn't help us help our families. The youtube videos, the blog posts, the essays - all of these platforms by which people with no real knowledge of vaccines, their components, or effects, have convinced you that vaccines are a giant conspiracy to enrich big Pharma at the expense of our children's health - are full of lies. Are there some people spreading this anti vax message because they genuinely think vaccines harmed their child? Yes. Are they right? No. They have been misled and are in turn misleading. This is not malicious on their part, but in order for us to best protect our children, we need to dig deeper and figure out what the truth really is. Hopefully, this post has helped with that.
If you still have questions, feel free to ask in the comments. I'm here to help.
- Offit et al. Addressing Parents' Concerns: Do Multiple Vaccines Overwhelm or Weaken the Infant's Immune System? Pediatrics. 2002; 109:1
- Daley et al. Assessing Potential Confounding and Misclassification Bias When Studying the Safety of the childhood immunization schedule. Acad Pediatr. 2018; 18(7):754
- Black et al. Apparent decreased risk of invasive bacterial disease after heterologous childhood immunization. Am J Dis Child. 1991; 145:746
- DeStefano et al. Increasing exposure to antibody-stimulating proteins and polysaccharides in vaccines is not associated with risk of autism. J Pediatrics. 2013; 163(2):561
- CDC on Multiple Vaccines