baby immune systems

A friend, bless her heart, is refusing to immunize her baby (now about 6 months). One of her “reasons” is that, she claims, a baby’s immune system isn’t active at 2 months and is just getting warmed up until 1 year or so. She believes that all those injections are traumatic to the baby and the as-yet-not-mature immune system. So I have 2 questions

  1. Does a baby’s immune system really need a ramp-up period?
  2. Where does this um…information…come from?

I’m well aware that there is an anti-immunization movement, particularly in the US, but what are the specific organizations that push this point of view, and are there any places where one can get a balanced-reporting sort of coverage of the issues?

I have no idea where she is getting her information from. Could it be she is getting confused about immunity from breast milk?
When babies are born they have a limited immunity and as breast milk is full of antibodies it helps boost their ability to fight off disease. As the baby gets older and is weaned off breast milk, the protection dwindles and they become more susceptible to disease.
Maybe your friend is getting her wires crossed. As far as I am aware the immune system is always active.
I am speculating here, but surely even if pumped full of antibodes via breast milk, you would need an active immune system to carry them about and have them do their job.
I am sure WhyNot will be along soon to sort it all out…

Paging Picunurse or Qadgop.

Well specifically Picunurse, she’s given us some REALLY good explinations of the immune system in the past.

Heh. Not so much. I’m incredibly confused on the vaccination (they’re not immunizations, really) debate, to be honest. My political stance is that mandatory vaccinations are a terrible idea, but that’s my Libertarian Mommy Rights hat talking. My personal stance is that, like all medical decisions, vaccinations should be considered on a case-by-case basis by the parents and the doctors of the child. I am outraged that in my state I cannot accept some vaccinations and refuse others and still get my kid into school. I’m also quite pissed off that I can’t use scientific doubt or even spiritual opposition as a rationale for a vaccination exemption, I have to word my refusal in very specific *religious *terms which include the word “God”, or it will be denied. But those are all POLITICAL exceptions I have to *mandatory *vaccinations, not medical ones to any vaccination.

As it happens, both *my *kids are vaccinated for most things. The 14 year old because I was too young to know I could say no, and the 2 year old because her micropreemie status and delicate lungs put her at an even greater risk from most vaccine-preventable illnesses than most children, so I made the medical decision, after seriously quizzing my doctor, to vaccinate her. However, I did delay her vaccination schedule to consider her due date as her birth date, with some things delayed a bit more than that. There is no special schedule for preemies, which means they wanted to start before her due date, and I said absolutely not, for reasons not unlike those in the OP. I felt that she hadn’t even finished her prenatal development yet, and I was not comfortable messing about with adding stress to her body while she was still learning to breathe on her own. I didn’t have to fight for that, the nurse actually seemed relieved that I wouldn’t sign and never mentioned it again while she was in the hospital.

As for the immune system question, I used to think that babies were fairly well sturdy from birth, but I was corrected about that in a Pit thread some years ago by an immunologist, who told me that even healthy full-term newborns have a less than fully functioning immune system. It’s a slow exposure to little things that “teaches” the immune system to function over time. So that’s probably where this mom is coming from. It’s a very common feeling in the anti-vaccination circles I’ve traveled in that a delayed and slower vaccination schedule might be gentler and safer on the infant’s system than the current recommended schedule which begins literally hours after birth. I don’t know of any scientific data to back this up, however.

So, I guess that was a longwinded way of saying I don’t have a GQ answer for this question, and I look forward to reading what others have to say about it.

I have no dog in this debate. But I wanted to clarify the science. I think you may have misunderstood the immunologist.

The immune system becomes robust over time by being ‘taught’ by antigens(i.e, Bacteria and viruses). THis is done because the immune system remembers past attackers and can respond very strongly the second time it is detected. This to having a list of things foods you don’t like. You have no idea if something is going to taste like shit until you try it. But once you do you’ll never touch the stuff again.

A 5 year olds immune system isn’t less functional then an adults immune system. it in fact functions exactly the same. The adult immune system has simply been ‘educated’ to more things. This education is in fact the idea behind all vaccines. Vaccines teach the immune system to reject pathogenic(disease-casuing) viruses by showing the immune system something that looks very similar to the actual disease causing virus. This can be non-infectious virus subunits, dead viruses, or related, but non-pathogenic viruses. Again, It is not that the 5 year old’s immune system gains functionality, but that it simply isn’t educated.

I used a 5 year old in the above example because I do not know with absolute certainty if a new-born baby’s immune system is actually fully developed. I would imagine it is otherwise all babies would constantly be reinfecting themselves with the same thing.

As much as I dislike giving the anti-vaccination crowd fodder, they are actually somewhat right in this matter. Only certain parts of the immune system are not fully developed for the first year of life. Specifically, infants experience a transient deficiency in IgG. It is not until about the sixth month that they start to produce IgG, and even then the response is not as robust as it could be. Infants receive IgG through the placenta during gestation, but these levels fall as the infant breaks down the antibodies after birth. Breast milk can supplement the infant’s supply to help the infant through this low period of production.

For more information, see Janeway’s Immunobiology pg 439-440.

Ok. I did a cursory review of my immunology textbooks.

Guy In the Corner,
Could you specifically quote the lines that say that Infants do not produce IgG -at all- until the 6th month mark? I find that exceedingly difficult to believe.

An overall deficiency in IgG is meaningless. What matters are what SPECIFIC igG antibodies do you produce. I do however know that the lack of a robust immune response (and therefore the need for booster shots) in the fetal immune system is actually caused by those very maternal antibodies that protect the baby. Those maternal antibodies actually attack the invading organisms before the baby has a chance to recognize it themselves. In which case it still makes alot of sense to vaccinate. PArtial immunity caused by an innocuous vaccine is alot better then true immunity caused by the actual organism after those maternal antibodies are gone.

There is no transfer of antibodies in mothers milk, this has been covered before as well here by Gabriela.

What? I think you misunderstood. In this post, gabriela said “… newborns whether breastfed or not are at more risk from TB. And this may be because the body fights off TB with cell-mediated immunity, not antibodies. And the mother cannot transfer the whole apparatus of cell-mediated immunity (a large network of several kinds of white cells checking with eachother and responding via interleukins about a potential enemy) through her breast milk.” Implying that antibodies are transferred through breast milk, but that they are insufficient for fighting off tuberculosis.

Convincing the “I think the CDC has no idea what my baby should get” anti-immunization crowd that the CDC is not a conspiracy is no more effective than working on the JFK or 9-11 crowd. Part of the mothering gene is to control your own child’s destiny and mistrust outsiders. This creates a filter which distorts information intake so that all some parents hear is information why they might not want to vaccinate their child. It’s no different than any other conspiracy psychology–bits and pieces with a particular slant, predicated on a distrust of Authority.

It’s highly unlikely a technical discussion of the whys and hows of immunization programs will convince a layperson who has already decided their ability to grasp immunology exceeds the consensus opinion of scientists.

Immunizations are not absolutely without risk. The safest course is to have everyone but you (or your baby) take the risk. This eliminates the wild vector and therefore the disease, with no risk to you. For this reason, vaccination programs are hard to drive when the diseases they are preventing are already rare in that population, and it is for this reason that vaccination is required by law.

We have been living in the lap of disease-free luxury so long that we have forgotten the extent to which mass vaccination programs have created a fat and healthy citizenry.

As a surly old physician whose kids are grown I’m sorta hoping the anti-vaccine crowd becomes successful enough that diseases raise their ugly heads again and we get a good outbreak of something that bumps off enough kids to put the issue at rest again for awhile. The net net will be saved lives. It would be even better if it were the parents who croaked, but I forgot that detail when I designed the world.

ETA: Yes I am a terrible person.

NoCoolUserName, is your friend refusing to immunize her baby, or refusing to immunize her now? I admit I don’t know much about why the vaccination schedules are set the way they are, but I’m guessing it has more to do with making sure everyone gets their shots in as few visits as possible in order to maximize participation rather than what’s medically the ideal approach. My kids are fully immunized and my oldest has always been done on schedule. My youngest, though, had health issues as an infant, so we delayed some of his vaccinations.

Incidentally, his health issues prompted his doctors to test his immune system. He was found to be IgA deficient. They told me to keep an eye on him for certain issues (asthma, allergies), but also said the test could mean nothing because babies his age (5.5 months at the time) typically show low levels of IgA…they don’t get fully ramped up until after 6 months and some kids don’t reach normal levels until age 2-3.

Chief Pedant, while I agree with you that some of the no-vax crowd is pretty loony, I don’t think it’s unreasonable for a parent to question and investigate exactly what is going into their kid’s body and what the ramifications are. Maybe I took your post the wrong way, but you sound very condescending to parents (well, just mothers, actually) who don’t blindly obey their doctors. I’ve read a ton of anti-vax stuff on parenting message boards and there are a lot of different reasons people don’t immunize their children. Some are, like you said, relying on “herd immunity.” Some do believe there are conspiracies involving the CDC and “Big Pharm.” There are others, though, who have had older kids with severe reactions to vaccinations and still many more who are not avoiding vaccinations entirely, but merely delaying or splitting them up (instead of getting many shots or combined shots done in one day).

It sounds like the OP’s friend could be a member of this last group and I don’t see what the problem is with taking a more cautious approach to vaccinations, as long as the child is getting all the most important ones* in the end.

*this wording is directed at the chicken pox vaccine, which I personally think is stupid

No, I hadn’t misunderstood, but thank you for the clarification anyway. The anti-infant vaccination idea understands that, and further thinks that the baby’s immune system is busy enough learning to fight off whatever pathogens it encounters in the baby’s environment naturally, through being handled, being sneezed on, sucking on things that have been dropped on the floor, etc. Adding additional stress to the immune system is worrisome, when one thinks about other (perhaps not comprable, I don’t know) multi-immune challenges, like getting a secondary bacterial infection while you have a cold. The thought is that the immune system has only finite capabilities, and if you “overwhelm” the system with lots of vaccines AND natural exposure all at once, maybe things go wrong. Maybe the system can’t handle it and the kid gets a full blown case of whatever thing we’re trying to prevent and dies from it - when she might have survived it had she gotten it later on her own or later from a shot, or, statistically, not gotten it at all. Maybe she gets a high fever and seizes as a result, and wouldn’t have if not vaccinated. Maybe something else happens to an overwhelmed system, and the kid is never the same again. Finally, there’s a great skepticism that vaccines are actually effective - everyone has a story of an unvaccinated kid who never got more than a cold and a vaccinated classroom who got put out of commission from measles despite their vaccines. People are under the impression that the rates of complications from, say, measles, are less than the rates of complications from the vaccine - that the chance of your kid dying of measles is less than the chance of your kid being irreparably damaged by the vaccine. Modern sanitation and the disease cycle of the vaccine-preventable diseases is thought to have more with reduced vaccine-preventable disease than the mandatory vaccination programs.

Again, I’m not saying I, or anyone else, has any evidence of this. I want to be clear that I’m not trying to present a GQ-worthy defense of the anti-infant vaccination point of view. I can’t, and I don’t think anyone else can, either (or if they can, I haven’t heard it yet.) All I’m trying to do is explain the thinking to you folks (most of whom, board history has shown, aren’t on that “side” of things) so that you can understand the fears parents spread to each other that keep them from vaccinating.

No, I don’t know who the organized groups are these days. But this is what’s discussed around the hummus whenever I have a party, by lots of very intelligent people, some of whom have M.D. or R.N. listed after their name. Sure, they’re fringy M.D.s and R.N.s, but this anti-vaccination stance is not limited to the ultra-religious or ultra-granola crunchy folks. That doesn’t mean that it’s any more valid, but I do think we need to actually address the concerns that parents have, and not simply shout at them that they’re stupid whackos, IF our intent is to actually figure out what’s best for the babies individually as well as the population as a whole. I can’t think of another subject where people are intentionally misled into willingly sacrificing their children, by a single action, for the greater good. Of course that’s hard to convince people to do! Parents get rather attached to their sprog. :wink:

That isn’t the problem here because the baby is able to produce normal levels of IgM almost immediately which are able to respond to an antigenic insult.

Breast milk, 100%, contains IgA and IgG.

I think that parents ought to be able to make decisions for their children’s health, within reason. Among the decisions I think should ultimately be left to parents is vaccination.

On the issue of vaccinations in particular, the only workable model is to come to a national consensus opinion and then find mechanisms to effect it. If that mechanism is to require vaccination of everyone, even though the vaccination may be dangerous for some, I have derision toward those unwilling to take a tiny risk for their child in the interest of the broader good of society. This selfishness, applied broadly, breaks down society and generally speaking benefits the privileged over the underprivileged.

I am all for healthy, scientific and robust debate over what the consensus should be. Toward those who take a contrary route to the consensus opinion, I hold no particular grudge as long as they do not want public tax money or sympathy if their kid falls ill from a preventable illness. It is true that I have condescension toward uneducated opinions, but of course in the area of vaccination, there are many educated contrary opinions. My personal observation is that the average motivation is personal selfishness over public good. Since I was never a pediatrician my opinion should be taken as a lay opinion on this.

I have no medical training, but I am doing more reading about this right now as I am pregnant. The books that I have (I can look for specific sites if you want) all do recommend that a newborn child not be exposed to public places for at least the first 6 weeks or so. Taking a newborn to the grocery store, or to a nursery or daycare is cautioned against, and the reason always seems to be that their immune systems are not fully functioning yet. I don’t have a book that goes into much detail about that though, but that seems to be the paranoia new parents have about sanitizing everything for a new baby.

I remember reading that the mother passes on benefits in utero that stay with the child for a while, and also through breast milk, but as the child ages their immune system is better at fighting off infection on their own.

That said, another reason may just be that newborns are potentially more harmed by diseases that don’t affect older kids as much, not necessarily that they can catch them easier. That’s a different scenario. I know certain diseases are much more dangerous to a newborn than say, a 2 year old. However, the reverse is also true sometimes, that diseases that are relatively minor in a child are really tough on adults. So it might just depend on the nature of the disease.

(BTW, I expect there to be more debate about this and vaccinating now that Oprah has made it mainstream. I saw a show last week where Jenny McCarthy all but outright claimed a vaccine caused her son to become autistic…although she also claims she has all but “cured” him… and claimed the CDC is ignoring mothers. What used to be a fringe movement might become more widespread if Oprah seems to be endorsing it, as sad as that sounds.)

Your interpretation is incorrect. Saying the mother cannot pass the whole apparatus of cell mediated immunity through her breast milk is kind of like saying you cannot get a whole elephant through a 6" porthole. You could, but you would not have a functioning elephant on the other side. There is no mechanism for passing functional components of moms immune system via milk through babys digestive tract into the bloodstream to help fight infection.

If anything baby will be subjected to pathogens mom has on board via milk which baby will immediately begin generating an immune response against because of being exposed to them.

This was confirmed by doper Cyn RN (and my wife) as well she worked for years in labor/deliver/postpartum dealing with moms and 0-72 hour old babies.

I think the confusion is that IgA is secreted in breast milk, but it’s not passed on to the baby that way. IgA is the most common immunoglobulin found in the body because it’s found in all secretions. IgG, on the other hand, is passed to the baby through the placenta.
Also, perhaps the OP’s friend is confused about why doctors don’t give vaccinations immediately? If you give it too soon, the mother’s antibodies are still present in the baby, and thus are going to suck up all the vaccination before the baby’s immune system has a chance to respond. This isn’t going to be bad for the baby, but it’s a waste of a vaccine. Usually you wait until most of the maternal antibodies are gone before you give the vaccination.

Actually, IgG is the most common isotype found in the body.

In the U.S. (and in Australia), the first HepB vax is given in the hospital at one or two days of age. Why is that one not sucked up by the mother’s antibodies? That’s certainly not long enough for the maternal antibodies to be gone, is it?

The maternal antibodies are still there. They take about six months to totally degrade. Maternal antibodies don’t “suck” the antigen. The antibodies can bind to the antigen presented by the vaccination. The antibodies act as opsonins making it easier for macrophages to phagocytose the antigen. These can then be displayed on MHC molecules allowing a response to develop eventually leading to the formation of memory cells. In essence, maternal antibodies make it easier for the baby’s immune system to handle the insult.