I’ve always heard that babies have this uber immune system when their born. Well mine is 4 weeks old and definately has a cold. So I was thinking that the the whole uber immune system may be a myth because generally our immune system gets built over time as it gets exposed to different germs and pathogens. On the other hand they may be so chock full o’ white blood cells that they just overpower most germs even though they don’t have a specific fighting method programmed. So what’s the straight dope? Do baby’s have accelerated immune systems for a while after their born?
Babies have OK immune systems when they’re born - like right when they’re born, due to the fact that many (but not all) of mom’s antibodies cross over the plactenal barrier and also protect the infant. These “borrowed” antibodies are not produced by the baby’s body, however, so when they die off, the baby is just as susceptible to viruses as anyone who’s never been exposed. Most of these antibodies die off in a few weeks, though some live for a few months. I wouldn’t call it an “uber” immune system. It’s certainly not better than mom’s. (Unless mom is immunocompromised.)
You can, however, continue passing many of your antibodies to the baby by breastfeeding. This passes some specific antibodies (antibodies that are formulated to attack a specific virus, like measles*) as well as “general” antibodies, which can attack an array of invaders.
*Measles antibodies in particular are present in breast milk of only mothers who themselves have had measles. One of the unfortunate side effects of childhood measles vaccination is that those antibodies from vaccination are not passed in the breast milk, so babies whose moms were vaccinated are not themselves protected until they get their MMR at 15 months.
The first beastmilk is called colostrum, I think, and it provides the baby’s immune system with a lot of help. If you don’t breastfeed, you don’t get that benefit.
FYI, my understanding is that mammals in general produce colostrum as “first milk” and that’s why animals that have a lot of pups or kits or whatever wait until all of them are born before they allow the babies to nurse. I saw that on a nature show on lions, though, so I may be incorrect or it may not apply to all mammals. It makes sense though that you’d want all the babies to get the benefit.