Published onParents PACK
- Do children get too many vaccines?
- Is a child’s immune system developed enough at birth to get the hepatitis B vaccine?
- Does my child still need vaccines if I am breastfeeding?
- How many vaccines can a child handle at one time?
- Why are multiple doses of some vaccines needed?
At their heart, these questions all hinge on understanding how the immune system works. But, many parents never had much in the way of formal education related to the immune system and how it works. In addition, scientists continue to learn more about the intricate interactions of the immune system that are just as important, and ever-present, as those that control the beating of our hearts and the breaths we take.
The immune system works from the moment we are born. It has to. In the womb, babies are in a sterile environment, but the birth canal is not sterile, nor is the incubator in which the newborn is placed — or the air in the delivery room for that matter. If our immune systems were not ready to leap into action as soon as we were born, humanity would not survive.
While some aspects of the immune system get better at their “jobs” over time, for the most part, the immune system has the tools necessary to protect us from the moment of birth.
Trillions of bacteria
As mentioned, the environment is not sterile, and that is good for a couple of reasons. First, some bacteria live on our skin and in our digestive tract and help to keep us healthy, mainly by contributing to an environment that is less friendly for potential disease-causing agents and by “filling up space,” so that pathogens can’t gain access to our cells.
Shortly after birth, bacteria can be found lining the nose, throat and intestines of all newborns. These bacteria provide a variety of functions, including helping to digest food and make vitamin K. In fact, bacteria have been detected in low levels in breast milk, suggesting that it is important that mothers transfer these bacteria to their babies' intestinal tracts.
By the time we are adults, we carry around tens of trillions of bacteria with us everywhere we go.
Training our immune systems
Another reason the non-sterile environment is important is that it affords a baby’s immune system the opportunity to “practice” generating its own immune responses and, in the process, allows the baby to develop immunologic memory against potential pathogens. To allow a baby’s immune system time to generate its own immunologic memory, babies are first protected by maternal antibodies that either crossed the placenta or were delivered in breast milk.
A deeper dive
The Vaccine Education Center recently added a new section about the human immune system to its website. The section goes into much more detail about some of the ideas described above, as well as offers a variety of other information about the immune system. Pages in the new section include information about:
- Development of the immune system in babies
- Parts of the immune system
- Types of immunity
- How the immune system works
- What happens when the immune system does not work properly
Categories: Parents PACK June 2019
Materials in this section are updated as new information and vaccines become available. The Vaccine Education Center staff regularly reviews materials for accuracy.
You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family's personal health. You should not use it to replace any relationship with a physician or other qualified healthcare professional. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult your physician or, in serious cases, seek immediate assistance from emergency personnel.