It’s only natural that pregnant mothers are paranoid about injecting themselves with unfamiliar substances. The rampant hype about swine flu has been swirling in a cloud of antivaccine misinformation, which has created a perfect storm of fear. Pregnant friends and family members have contacted me for reassurance that the H1N1 vaccine will not harm their unborn babies.
I know one thing. If a pregnant mother dies from swine flu then the question of potential vaccine harm doesn’t matter. Pregnant mothers are at a higher risk of contracting H1N1, and they have higher rates of mortality. There’s also not been comprehensive studies on the antiviral tamiflu that has been routinely used on pregnant women, so there’s an unknown risk with that too.
My friend Stacy visited last week. Her pregnant sister recently contracted swine flu, so this issue has really hit close to home. Stacy’s sister was tested, but the results were negative until they were retested at another facility. The flu, swine or not, is extremely unpleasant (hacking up your lungs and aching from head to tow). Imagine having to suffer the flu while dealing with the discomfort of being with child. I’m sure Stacy’s sister would have taken the vaccine if it were available.
I’m not an expert by any means, so let me just restate the information available from the CDC, an agency designed to prevent communicable disease.
- H1N1 vaccines are made in the same way that any other recommended flu vaccines have been made.
- The generic flu vaccine has undergone safety testing on pregnant women and has proven it’s efficacy.
- Thimerosal (a mercury-based preservative) has consistently proven it’s efficacy, but just like any flu vaccine, you can still opt for a mercury-free dose. The non-bio-accumulative mercury in thimerosal (ethylmercury) is an entirely different compound than the toxic mercury in tuna fish (methylmercury).
- Taking the flu vaccine will NOT give you the flu.
- Pregnant women are given the jab (not the nasal spray) because the virus is dead in the jab.
- Don’t receive the vaccine if you are highly allergic to eggs. Every flu vaccine of a similar strain is incubated in one singular egg.
- ETA: Sanjay Gupta (on Larry King) also reminded me that pregnant mothers who vaccinate may also pass on some of their immunity to the unborn child. Bonus! *
There are several other resources that are worth checking out: Amy Tuteur of Skeptical OB, Mark Crislip of Science-Based Medicine, and the anonymous epidemiologists at Effect Measure
Skeptic Family 
I’m printing this out for our faculty lounge. Will the H1N1 vaccine be available for the general public? I’m asthmatic and work in a school that has already had H1N1 illness this year. (We didn’t shut down just emphasized hand washing, coughing into the elbow (doesn’t work for me), making an effort to wipe down desks, door handles, and keyboards.
Several of us spent time assuring co-workers they couldn’t get the regular flu from the shot because it was dead virus. So several people got that shot on Friday when it was offered. (I got it earlier because of the asthma).
One co-worker had been insisting for weeks that she got violently ill every time she took the flu shot. I suggested she look at the possibility she is allergic to eggs or another ingredient. She talked to the her doctor they tested her and sure enough she is allergic to eggs.
By: kherbert on October 11, 2009
at 3:22 pm
Check your facts. The “immunities passed from mother to unborn child” thing that gets repeated ad nauseam applies only to gastrointestinal bugs. All immunities are not the same, and there is zero evidence that your flu vaccination will benefit your baby, except that you might survive to deliver him. You should still get immunized for flu, and the immunities that babies get from their mothers are valuable, but they do not make up for lack of vaccination. No no no. Look it up. And shame on whoever-it-was on Larry King. I hope he/she isn’t an MD, spreading that wrong information
By: PDXscience on October 12, 2009
at 3:14 pm
Thanks for the tip. Sanjay Gupta is the celebrity doctor who was in contention for surgeon general. I will double check that fact. Sorry about that.
Here’s a link to the video where he makes the statement @ 3:22.
By: Ticktock on October 12, 2009
at 3:17 pm
I asked the experts at the Effect Measure blog about this correction, and this was their reply…
“ticktock: There will be some passive immunity transfered transplacentally. How much protection that provides is unclear (if any), but it wanes in months (if it is effective at all). So “inherited” isn’t the right word. The sense, though, I suppose makes it possibly remotely true. By the time they are 6 months that’s gone and they should get vaccinated.”
By: Ticktock on October 12, 2009
at 9:07 pm
Passive immunity is a technical term here, meaning that the person didn’t create the antibodies themselves.
It has been known since at least 1980 that maternal IgG is at a higher concentration in cord blood than in maternal blood, suggesting that the mother’s body is actively concentrating these antibodies for her offspring.
The process works for influenza A in ferrets, I’m guessing exposing baby humans to influenza to see how effective it is going to be a hard sell to the ethics committee. The effectiveness or otherwise can probably be estimated if we have another epidemic.
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1453355
Fascinating science. Previously my knowledge on maternal antibodies transfer was limited to Graves’ disease, where mothers pass antibodies causing hyperthyroidism to their babies. Which leads to a transient overactive thyroid in the baby.
By: Simon on October 13, 2009
at 3:29 am
I have to say, I am still reluctant about this vaccine. This is all happening so quickly, and it seems that the scare of the flu is the worst part of it, not so much those affected. I would have rathered that we spent the time and money on something more important to us like Alzheimer’s and breast cancer, rather than a flu vaccine that might have been treatable with a normal vaccine that we know more about.
By: Erin on October 12, 2009
at 3:29 pm
A quick Google scholar search suggests that placental transport of IgG antibodies results in detectable levels of antibodies in neonates for influenza (the types studied at least) from vaccination of the mother during pregnancy. The paper also notes that 6 months is a minimum age for influenza vaccination, so Larry King’s doctor appears to be spot on with his facts.
Click to access immunity-12.pdf
Journal of Clinical Virology 46 (2009) 161–164
One of my partners friends, just lost a 10 year old nephew to suspected Swine flu. It is going to be a grim old autumn for many I fear.
By: Simon on October 12, 2009
at 6:10 pm
Sorry that is not from vaccination, but the results support vaccination of pregnant women. Anyway it is free to read, so read it and don’t rely on my muddled brain!
By: Simon on October 12, 2009
at 6:14 pm