Disappointing to see the UK take such a strong & overly precautionary position against vaccinating pregnant and lactating people (incl. requiring pregnancy tests) with the recently approved Pfizer/BioNTech vaccine. A thread on why this is problematic (1/n) https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/940565/Information_for_Healthcare_Professionals_on_Pfizer_BioNTech_COVID-19_vaccine.pdf

There is a difference bw saying "Don't give vaccines to x population" vs "We don't yet have evidence to support a positive recommendation." The former "contraindication" suggests that there are risks to be concerned about, the latter reflects the actual state of uncertainty (2/n)

To be clear, we haven't seen any evidence of risks with this product in pregnancy or lactation, or any signals from animal data... though unfortunately we also don't yet have much data to look at since these populations were largely excluded from trials & DART data pending (3/n)

But, as I and others have said before: (4/n)

Also, starting with a contraindication can be quite difficult to walk back from, as and when the fact situation changes and evidence supports a positive recommendation. Not only is it hard to effectively convey how you go from a hard "no" to a positive recommendation... (5/n)

But language on product labels often stays unchanged with precautionary language not to use while pregnant or breastfeeding, even when public health agencies/WHO have good evidence to advise using it. Just look at harms to maternal flu immunization (6/n) https://www.sciencedirect.com/science/article/pii/S0264410X16307149

Then the issue w lactation precaution. Having a hard time imagining what biologically plausible risk there might be to breastfeeding infants from this vaccine. If anything, they stand to benefit if antibodies transferred via breastmilk (7/n) https://www.sciencemag.org/news/2020/11/breast-milk-contains-coronavirus-antibodies-study-suggests

Not only seems like an unjustifiable exclusion w/ serious implications for many people of childbearing potential who will be unfairly denied/delayed benefits of covid vaccination, but also lets not forget how many people in essential workforces are pregnant or breastfeeding (8/n)

If both pregnancy and lactation are contraindications for vaccination, what is the plan to protect all those who we rely on as a society to provide health services, care, education, and so many other critical services??? (9/n)

For regulatory agencies/advisory bodies working on positions re vax in pregnancy & lactation:
- burden of proof on you to justify exclusion, w science & risk/ben assessment
- assess pregnancy & lactation as distinct groups
- there are permissive stances that speak to uncertainty