Frederike Schmitz
COVID-19 vaccination during pregnancy: more positive messages please!

In my last blog I promised you an analysis of the Q&A landscape on COVID-19 questions from children. Before I get to that I wanted to share a thought with you I’ve been thinking about the past week.
I closely follow the debate on social media about vaccinating while pregnant against SARSCoV2.
As I have written about in an earlier blog post, I personally found it complicated to decide whether or not to vaccinate while being pregnant.
And I have a scientific education- a PhD in immunology- so I can read up on scientific literature and then come to a conclusion.
Based on science.
That most other pregnant people can’t do that is only logical.
That is why I think there should be a lot more guidance on how to decide.
So far, as I have described before, the messaging was either neutral up to plain out confusing.
Apparently with the immense COVID-19 numbers in the UK their public health messaging now seems to change.
What they are seeing there is a rise in hospitalizations of pregnant people with COVID-19.
Can you imagine being pregnant and experiencing severe COVID-19? Severe enough for a hospital admission?
I had a stomach flu, probably a Norovirus, during my first pregnancy and I still remember how awful it is when you feel sick while you’re really pregnant.
You must know that a pregnant person in their last trimester is not the fittest.
Your lung volumes are smaller due to the baby taking up a lot of space.
You carry lots more weight.
Your body is full of hormones which weaken all your connective tissue.
All of this makes even the fittest (and I consider myself rather sporty) rather unfit ;)
Now, imagine you get a severe SARSCoV2 infection and need additional oxygen.
That the numbers of hospitalization rates amongst pregnant people are rising in the UK is not really surprising. Some articles state that probably only about 50% of pregnant people are getting vaccinated. I suppose we’re still missing the real numbers, but they can’t get high.
How could they?
If the public health messaging is on the spectrum of “oh it’s up to you” to “we don’t recommend it due to the lack of data”, it’s no surprise really.
Who would decide in favor of vaccinating if you’re not familiar with the data and the science?
If nobody takes the time to walk you through it? To weight the pros and cons with you?
Also midwifes (at least what I can tell from my experience here in the Netherlands) leave it completely up to you. They often don’t even mention it. They don’t ask for your thoughts and feelings about getting vaccinated.
And if you see information now appearing from the UK where they have apparently shifted their public health messaging from “up to you” to “you should do it” – because of such drastic rises in hospitalizations- the message is still very much “you should do it because it seems safe”.
I however would like to see more positive messaging.

There are some studies now that have been looking at the passive transfer of antibodies from mothers after infection or vaccination to their unborn child. Or in case if they are breastfeeding, to their babies.
I spoke about ‘passive immunity’ in my previous blog explaining the phenomenon of sharing an immune response with your baby. That to me is a brilliant thing and definitely worth mentioning.
I think that the public health sector can learn a lot from marketing.
The slogan “you want the best for your baby” is very effective. It’s subconsciously used so much for marketing anything baby related to future mothers, that it repeatedly annoys me.
Yes, I do want the best for my baby but that doesn’t mean I have to buy the new co-sleeper for the price of a car!
But “you want the best for your baby” definitely applies when you choose to vaccinate against COVID-19. Because you likely not only care about your own health (“it seems safe for your health”) but you also care about your baby’s health (“it seems safe for your unborn baby or your breastfed baby”).
AND you probably care about protecting your baby from future threats.
Once vaccinated you make antibodies against the virus and pass that on to your unborn child.
The public health message should be “By vaccinating you protect yourself and likely your child from a future SARSCoV2 infection”.
Of course, these studies are (relatively) new and just emerging, and I’m not sure at what stage public health institutes regard it as sufficient data to adjust their messaging, but the lack of positive reassurance in that sense is very striking to me.
I hope that that will change in the near future.
And I do hope that we will see more studies investigating if indeed passive antibodies from the mother can prevent a future SARSCoV2 infection in babies who’s mothers have been vaccinated.
If you want to read up on some published scientific studies or the main takeaways:
Efficient maternal to neonatal transfer of antibodies against SARS-CoV-2 and BNT162b2 mRNA COVID-19 vaccine. Main takeaway: The Pfizer/BioNTech vaccine generated strong (IgG) antibody responses in mothers that also crosses the placenta barrier and is found in the fetus. IgG is a very specific, selective and mature- so to speak- type of antibody usually found in blood. IgM is the first version (version 1.0) of antibodies one makes when encountering a threat. It is not as specific as IgG.

Coronavirus disease 2019 vaccine response in pregnant and lactating women: a cohort study. Main takeaway: Vaccine-generated antibodies were found in mothers, in the baby's blood (or more specific in the umbilical cord blood right after delivery) and in breastmilk. Thus immune transfer to the unborn baby works. Vaccine-induced immune responses were even greater than the response to natural infection.
Cord blood antibodies following maternal coronavirus disease 2019 vaccination during pregnancy Main takeaway: Antibodies could be passed on from the mother to the child after receiving the Pfizer/BioNTech or Moderna vaccine in their third trimester. Also here, the effect was even stronger after the vaccine than the natural infection.
Worth noting:
Both last two studies seem to indicate that an earlier vaccination (in the 2nd trimester) may result in an even greater immune transfer to the baby. Let's see how this spans out. Would be worth knowing when the best time to vaccinate during pregnancy actually is. That is of course, if you can choose when to vaccinate.