Pediatricians Discuss Vaccines and Breastfeeding

Pediatricians discuss vaccines and breastfeeding

Amna Husain, MD: Hi, I'm Dr. Amna Husain, board-certified pediatrician and board-certified lactation consultant. I'm also a mom of two girls.

Paul Offit, MD: Hi, my name is Paul Offit. I'm the Director of the Vaccine Education Center at the Children's Hospital of Philadelphia and a Professor of Pediatrics at the Perelman School of Medicine at the University of Pennsylvania.

Amna Husain, MD: So Paul, in my practice I commonly have families and moms in particular ask me that if they're breastfeeding, can they delay vaccinations? What do you usually say?

Paul Offit, MD: So, there's no reason to delay vaccinations while you're breastfeeding. Breastfeeding obviously is of tremendous value. I mean, you're coating the lining of the upper intestinal tract with, you know, with valuable nutrients and antibodies, so there's really no reason to stop.

Amna Husain, MD: Right. I think that's a really great point. And we know that there's not just data tied to vaccines and immunity when it comes to breastfeeding, but also other great things, you know, autoimmune diseases, prevention of ear infections, a lot of great data.

Generally, I think that it's also really helpful to point out to families, and I'm sure you do this as well, that there's different types of immunity, different types of antibody that you would get. So, the types of antibodies that we provide with breastfeeding are different than the types of antibodies that vaccinations would provide.

Paul Offit, MD: There are different subtypes of antibodies. One of them is a subtype that typically lives at sort of mucosal surfaces, like the lining of the nose and throat and intestine, called secretory immunoglobulin A. The other antibody is typically immunoglobulin G. So, when you're vaccinated, the baby will acquire immunoglobulin G through the placenta starting at around 32 weeks’ gestation, but not immunoglobulin A. Immunoglobulin A, which is the one that is really hardy and that it really lives easily at mucosal surfaces, is the one that you get with breastfeeding. You also get immunoglobulin G as well. Neither of them are absorbed into the circulation. So really, a baby's immunoglobulin profile in the circulation is very similar to the mother's immunoglobulin profile.

Amna Husain, MD: I think that's a really great point. I think that's why it's really helpful to think about a child’s or even an infant's antibody profile during pregnancy, through breastfeeding if you choose to breastfeed, and then later on if you choose not to breastfeed even if you wanted to go forward with vaccinating your child, you're providing different types of antibody protection, which is really, really important to see the full big picture.

Paul Offit, MD: So, in summary it's while when you're born, you have the mother's antibody profile in the circulation, meaning the bloodstream, which is the so-called immunoglobulin G, which is typically what you find after vaccination, but when you're breastfeeding, you have this additional antibody, the so-called secretory immunoglobulin A, which bathes the mucosal surfaces. It’s very hardy and long-lived at the mucosal surface because it doesn't break down. So that's the advantage of breastfeeding

Amna Husain, MD: Right now, we're in the middle of cold and flu season. Can a mother who's breastfeeding get the flu vaccine, for example?

Paul Offit, MD: Yes. It's important for a mother to get the flu vaccine while breastfeeding. Important for the mother to get all the vaccines that she needs. And in fact what happens is, is that when she gets the flu vaccine, she'll then generate an antibody response, which to some extent will be passively transferred to the baby in breastfeeding, at least for a certain period of time. She needs it to protect herself, and by protecting herself, she's also protecting her child from influenza.

Amna Husain, MD: For sure. I think that's a great point. So, I'll use myself as an example. My daughter was born before, you know, during cold and flu season and she was before 6 months, which is the youngest age we can give the flu vaccine. So honestly, both my girls the best way I could protect them was for my oldest getting the vaccine while I was pregnant, so she was, again, able to get those antibodies as an infant. And for my 4-month-old right now who still can't receive the flu vaccine, I got vaccinated while still being able to nurse her. So, I think the important thing you pointed out here is not only can the baby get the antibody benefit from mother, but the mother is also protecting herself and baby.

Of course, the safer way to get that, you know, beneficial antibody protection is obviously through a vaccine rather than, you know, acquiring influenza and then potentially getting very sick myself or infecting my two little kids.

So that brings me to another question I commonly get. Do the antibodies in breast milk often interfere with vaccine responses in any way?

Paul Offit, MD: They can. I mean, so for example, with the rotavirus vaccine … so, rotavirus is a virus that causes fever and vomiting and diarrhea in young infants, primarily in the 6- to 24-month age group. So, you need to make sure that children are fully immune against that virus before they're 6 months of age. So that vaccine is given at 2, 4, 6 months of age by mouth. When those studies were done, actually initially in the United States, it was highly immunogenic and was able to protect — the vaccine was able to protect babies in that age group. When studies were first done then in the developing world, you found that there was somewhat of a lesser immune response because what happened was that there were much higher quantities of antibodies directed against rotavirus in the breast milk of women who lived in the developing world, say in Sub-Saharan Africa, as compared to the United States. The reason for that is that rotavirus is a winter disease in the United States, but in tropical climates, it's a year-round disease, and therefore people tend to have higher levels of antibodies against that virus, including in their breast milk. As it turns out, it didn't matter. You were still able to get an adequate enough immune response that you could protect that baby in those areas, in those countries that were around the equator, those so-called tropical climates.

But, no, antibodies in breast milk can interfere, which tells you again about the power of breastfeeding. I mean, the fact that those antibodies were able to neutralize the vaccine virus that was in the rotavirus vaccine.

Amna Husain, MD: That's really interesting. I had no idea. I think we have to think about what's the safest way to obtain these antibodies and then be able to confer immunity not only to ourselves, but then again to babies if you are breastfeeding.