First, let’s note that we do have some data on pregnancy from the COVID vaccine trials. Participants were asked not to become pregnant, but some did by accident. The outcomes for these pregnancies were monitored as part of the trials, with no concerns emerging. 2/
These ppl were told about what (little) data was available on these vaccines as well as the data on the harms of COVID 🦠 in pregnancy, and made an informed choice.
We collected data from the 1st 🤰🏻 vaccinees so future ones (in other countries) would be better informed.
5/
So was rolling the vaccine out to 🤰🏻 without trial data in that population okay?
They made an informed choice and safety was closely monitored, so I would say… yes.
But could we have done better?
Also yes! 6/
How? By including 🤰🏻 in the first round of clinical trials. This has 2 benefits…
1. Justice. It’s not fair ppl be excluded from the potential benefits of being in a trial just because they’re 🤰🏻
2. Knowledge. 🤰🏻 being offered 💉 in the general rollout wd have better info. 7/
Guidelines for the ethical inclusion of 🤰🏻 in vaccine trials were developed for use in Ebola and Zika outbreaks.
These could - and should - have been used in the COVID pandemic. We must do better next time. 8/
But can’t we exclude 🤰🏻 from the first round of trials, and only include them once we know a 💉 is safe and effective in the general population?
This is actually what we tried: Pfizer started a trial in 🤰🏻in February 2021.
But there are two problems with this approach… 9/
1. In a public health emergency, we need the data urgently. During the delay between the first trial data and that from 🤰🏻, this population will be in the same position as before - making a decision on limited data. 10/
2. If - as happened - it emerges from the general rollout that it’s much safer to get vaccinated than to remain unvaccinated, the placebo group in your trial will want to get vaccinated. And it’s not ethical to prevent them. 11/
This means you will only have a very short window of time where your trial is placebo controlled and blinded, which limits the ability to follow up outcomes in the control group and thus the usefulness of the trial. 12/
Because of this, lots of people (and me!) would advocate including pregnant people in the first round of vaccine trials in public health emergencies.
I’m going to link the guidelines developed for doing this again, because they’re great! 13/
Finally, why have I written this thread? In short because a lot of people have been asking “Is it okay that our safety in pregnancy data comes from the general rollout?” so I thought it was worth taking the time to write a nuanced answer to them. 14/14
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In December 2020, Pfizer submitted data on its vaccine to the MHRA for temporary approval, which was granted. The documents on this are in the public domain... 2/
Periodically, Pfizer sends the MHRA some more data. On 16 August, they sent some additional data on boosting with different brands of vaccine. The documents were updated accordingly. 3/
There seems to be some confusion because the full approval documents for the Pfizer vaccine - published a few weeks ago - note that Pfizer did not themselves do any studies of the vaccine in pregnancy.
But this document describes only the data that Pfizer submitted to the MHRA, not the independently generated data we have from universities and government bodies, which track vaccine safety in more than 315,000 pregnant people and find no problem. 3/
In fact, the authors found a slight reduction in the risk of stillbirth and very preterm birth among those vaccinated. Although they controlled for known confounders, they didn’t feel confident that this wasn’t due to residual confounding. 2/
However, it is in line with the findings from other large studies which show a reduced risk of stillbirth following vaccination… 3/
These data were published about a year ago, but ppl are talking about it today because Naomi Wolf has looked at the FOI data and claims she has found a miscarriage rate of 44%. Unclear how she has done this but seems to be a combination of… 2/
👉🏻 Accidentally counting everything twice (oops)
👉🏻 Counting some ppl who didn’t have miscarriages (eg. males)
👉🏻 Counting miscarriages among the control group (ie. ppl who did not get vaccinated). 3/3