Birth by C-section more than doubles odds of measles vaccine failure. Should I test?

[kaferty]

Have twins born by C-section 2 years ago. Kids got the MMR shots but have just seen the study that suggests that "Birth by C-section more than doubles odds of measles vaccine failure."

https://www.cam.ac.uk/research/news...-than-doubles-odds-of-measles-vaccine-failure

I mentioned this to the pediatrician who hasn't heard of the study.

Should I order the IgG test for measles immunity? Or is that overkill? Has anyone done this? Not sure if it's a test you order or if it must be done at a lab.

Is it possible the vaccine confers some protection, even if it fails?

 

[kimmie3]

@kaferty In general my advice would be that you shouldn't pay attention to a single study like this. There are countless things that can happen to make one study, particularly an observational one, produce results like these.

One of the most basic elements is that a lot of people go through the same data over and over again testing many hypotheses, so some of them turn out to be true by coincidence, but this is never recorded anywhere.

Another factor is that this is China, and I'm guessing from your English that this isn't where you're from. China has a very different MMR schedule. They give the MMR vaccine much earlier, more like 8 months; one of the earliest schedules worldwide. From my understanding looking at the paper it also seems like they first give a bivalent vaccine at 8 months and then the trivalent next time around? It's a bit unclear.

Actually, one of the conclusions from the paper is that they would be better off with the schedule we use in the West, MMR at 12 months, and it would work much better.

The science media center has two responses from scientists in the field: https://www.sciencemediacentre.org/...f-measles-vaccine-failure-with-a-single-dose/

Single studies also want to talk up their results. And in particular, news websites like the one you linked to want to talk up their results to get clicks! This results in very distorted messages.

That's why we have a rule that we want people to link to the story, not the news article. I didn't remove the post because it's a genuine question. The link is about halfway down. https://www.nature.com/articles/s41564-024-01694-x

Maybe you could edit the post to link to the paper?

Your kids will also get a 2nd dose soon.

 

[stonefist]

@kimmie3 This is the only comment OP needs to see.

 

[bht]

@kimmie3 They found that 12% of children born via caesarean section had no immune response to their first measles vaccination, as compared to 5% of children born by vaginal delivery.

I mean so 88% still had some immune response?

 

[mcbrideusa]

@kimmie3 This is definitely a flaw of the science based parenting rules for comments.

It doesn't allow CDC/NHS websites as sources, but does allow small trials that haven't been replicated or generally accepted by the field, as long as they're peer reviewed.

In other science-based areas, i.e. if you're writing Wikipedia articles in medicine, you can't use primary sources at all. Primary sources can be great, but always need to be contextualised.

 

[kimmie3]

@mcbrideusa The rules are more liberal in practice. But I agree, at the end of the day, we need to make a judgement call. Some sources are reputable and others aren't and there's no way to define that clearly.

 

[dugger]

@kaferty Correlation does not mean causation.

Yes, being born via c-section has been linked to reduced immune systems.

I would not be surprised if babies with pre-existing medical conditions in the womb are more likely to be born via c-section.

Having a pre-existing medical condition increases one's susceptibility to disease.

So, it may not be the c-section causing measles, it's being immunocompromised.

But, the only way to know for sure what causes these disparities in outcomes is to run a true experiment, where a sample of pregnant women are randomly assigned to either a c-section or vaginal delivery and then measure what happens with the babies afterwards. Obviously, this is not ethical, so the best we can do is identify correlations.

 

[ajs1342]

@dugger This is so true. I had a c-section because I had preeclampsia and my induction failed, but my baby was never in distress (and she was full term). I see a lot of conclusions drawn about c-section babies and worry, but I have to remind myself that there are so many baby-health related factors that lead to c-sections but don’t apply in my situation.

 

[danielson]

@ajs1342 Yeah my c section was because of an apparently narrow pelvis and she couldn't pass through, not because of a health concern with the baby

 

[euthymios]

@danielson I don’t even have a particularly narrow pelvis, my daughter just has her father’s enormous head! My OB actually laughed during my emergency c section and said ‘there was no way she was getting out’. She had a massive ring around her head where she was stuck.

 

[danielson]

@euthymios Yep maybe mine got my large head lol glad your baby arrived safe!!

 

[euthymios]

@danielson And yours! I know our daughter has been wearing hats for 3 year olds since she was 14 months old. Hopefully she’ll get his height and it’ll look proportionate!

 

[tay26338]

@euthymios Same. His head was so swollen! It was wild lol.

 

[mylilily]

@danielson Same.

 

[franjo]

@mylilily Same.

 

[fayequinn]

@franjo Same

 

[trueagnostic]

@fayequinn Same x2 here

 

[bobo4jc]

@dugger This is an interesting hypothesis and anecdotally true for my life.
3 kids and only the first born by c section because she required blood transfusions at birth. There was never any solid conclusion about why. Fast forward 5 years later and she is diagnosed with autoimmune encephalitis. No way to know but really does seem like it could have all been related.

 

[pninaelkayam]

@dugger Interesting - I didn't even know that about c-sections. So far that doesn't seem to be the case in my family. My 3-year-old was born via C-section, and whenever he brings home a cold or even a fever from daycare he bounces back quickly, as does my husband when he gets it. Meanwhile my 10-month-old who was born via VBAC and I are sick for a week! But maybe that will change as the baby gets older. The 3-year-old didn't get his first cold until 14 months, but I attribute that more to being a COVID baby who rarely went anywhere than to a super immune system.

 

[colinronald]

@dugger That makes a lot of sense! My baby was born via c-section due to being breech (so no real “medical” concerns) but so far at 17 months seems to have a very strong immune system despite being in daycare she’s barely gotten sick.