The use of antibiotics and the body’s immune response to vaccinations

Introduction – the effect of vaccines on human health has been marvellous. Some of the vaccines are given at a very young age, in order to build a good immune system in babies and children, especially in their first few years of life. Nonetheless, it is well known that children may respond differently to the same vaccine and that the response depends on different factors including genetic and environmental influences.
The relationship between a person’s level of immunity, be it a child or an adult, and the normal flora present in their gastrointestinal tract (microbiome) has been studied extensively in the past few years. Today, it is well known that changes made to the microbiome may have a significant impact on a person’s health and immune system.

What can cause changes to the microbiome? Administration of antibiotics, of-course, especially in children. I mean, your doctor can’t “request” that the antibiotic he prescribed for your child’s ear infection only destroy the “bad” bacteria in your child’s ear. This same antibiotic also destroys many other “good” bacteria, many of which are found in the intestines.
That is why the question behind the current research paper was whether there is an association between the administration of antibiotics at a young age and a child’s ability to develop antibodies against the childhood diseases for which he/she were vaccinated.
In simpler words – will a child who received many courses of antibiotics develop weaker immunity (in terms of antibodies), in comparison to a child who received no antibiotics at all?

Methods – the collection of data for this retrospective study was based on a cohort of children aged 6 months to 2 years that had undergone evaluation for a different prospective study. In the original study, that focused on ear infection in children, data regarding these children’s health was collected, including their vaccination status and their exposure to antibiotics. In addition, blood samples were taken from each child, at different stages of the study. The researchers from the current study simply collected data about the children from the original study, including regular childhood vaccination status and the receipt of antibiotics and they measured levels of antibodies against the diseases to which they had been vaccinated in the children’s blood samples. The difference between the levels of antibodies between the group of children that had received antibiotics and those that had not, were compared.

So, what is the association between antibiotics and vaccines?

Results – there was a total of 560 children, 342 had received antibiotics (1678 different antibiotic courses, that is, each child received an average of 5 courses during the period of study!) and 218 that had not received antibiotics at all. The only demographic difference revealed between the two groups was that there were twice as much children who went to day-care in the group that had received antibiotics than in the group that had not.

And what about the study question?

Well, children who received antibiotics had lower levels of antibodies in their blood, some even had levels below the minimum antibody titer required for protection from disease at the ages of 9 and 12 months. This means that children who had been properly vaccinated against a specific disease did not develop sufficient antibodies to protect them against the disease. Crazy, right?

Which antibiotics were found to have the worst influence? Newer generation Cephalosporins and amoxicillin and clavulanate (Augmentin). For amoxicillin and clavulanate, a short, 5-day course was not found to be associated with lower levels of antibodies but a longer 10-day course was indeed associated with lower levels of antibodies.

What about the antibiotic most commonly used in pediatrics worldwide? Amoxicillin was not associated with lower levels of antibodies. Phew, thank God!

Want to hear more? Here were go.
The study also found that the number of antibiotic courses that a child receives may also play a role. The more courses the child receives, the worse his body’s response to vaccines.

Discussion – Wow. Such an important research paper. Despite it being the first of its kind in children, it is still super important. What can we, as parents, learn from this study?
A. Realize that there is an association between the use of antibiotics and the child’s body’s response to the vaccines that he receives and that this association is probably connected to the microbiome.
B. Understand that broad-spectrum antibiotics have a more significant effect and even more so when given repeatedly and for longer periods of time.

So, what am I saying? Should we not give our children the antibiotics his doctor prescribed? That is not what I mean to be saying at all.

What I am saying is that you should discuss, together with your child’s doctor, the need for antibiotics. I believe that in many countries, around 50 percent (at least) of the antibiotic courses prescribed to children for ear infections are unnecessary. Read more about the ‘watchful waiting’ method used for treating ear infections here. This is a wonderful way to avoid unnecessary courses of antibiotics.

Discuss the length of treatment with the doctor – you can read more about a recent study that proved the efficacy of a short, 5-day, course of antibiotics, for pneumonia here. Some pediatricians haven’t heard about this research nor have they adopted its conclusions, yet.

Discuss the type of antibiotic chosen – one should always attempt to give the narrowest possible spectrum of antibiotic that is able to cover the bacteria causing the infection in your child. In other words, if you happen to leave your doctor’s office with a prescription for Amoxicillin and clavulanate too often, both you and him are in trouble. There has to be a really good reason for a doctor to prescribe Amoxicillin and clavulanate to a child.

Of course, just like in any study, this study too, had its limitations. And of course, many new questions have now emerged about the specifics behind the association between the microbiome and vaccines.

I hope the message is clear to all.

Antibiotics are a very powerful tool handled by doctors. They should be used wisely.

And don’t get me wrong, if your doctor has contemplated the need for antibiotics and decided to prescribe your child a course of antibiotics, make sure your child completes the course as recommended.