Thread by @VikiLovesFACS

It's another paper on #COVID19 #vaccination in #pregnancy and #breastfeeding, but with a twist...

How does being pregnant or breastfeeding affect responses to variants?

Does being pregnant or breastfeeding change T cell responses? 🧵

jamanetwork.com/journals/jama/…

The study looked at 30 pregnant, 16 breastfeeding and 57 ppl who were neither, who had been vaccinated with Moderna or Pfizer. Also 22 pregnant ppl and 6 non-pregnant ppl who had caught COVID.... 2/

They started by looking at antibody responses. Notice that we get more anti-Spike antibody in response to vaccination than natural infection.

This has been shown in other studies of COVID19 vaccination in pregnancy. 3/

medrxiv.org/content/10.110…

They also confirmed that the antibodies cross the placenta and get into breast milk. We might expect this to give babies some protection against COVID.

We knew this already, but always good to have confirmatory data! 4/

(You can find more studies that show the same thing linked in my explainer, here...) 5/

drive.google.com/file/d/1_wHIYX…

But no-one, so far as I know, has yet looked at T cell responses to COVID19 vaccination in pregnancy. But these guys do! 6/

The authors say that the T cell responses were comparable in ppl who were pregnant, breastfeeding, or neither.

Maybe there's no significant difference with these smallish numbers, but I do note a downward trend and I think that's worth keeping an eye on in larger studies. 7/

Finally, what about those variants? The authors looked at antibody and T cell responses to the original variant, as well as B.1.1.7 (UK) and B.1.351 (S. Africa).

Were these different in pregnant and breastfeeding ppl? 8/

The ability of antibodies to bind B.1.1.7 were the same as to the original virus. The ability to bind B.1.351 was reduced in all participants, regardless of pregnancy status.

Again, it's apparently not significant, but note the downward trend in antibody binding in 🤰🏻 &🤱🏽10/

The ability of T cells to respond to the variants was no different from their ability to respond to the original virus, regardless of pregnancy status. 11/

This is in line with findings published in the non-pregnant population, where we see B.1.351 partially evading the vaccine-induced antibody response, but still being recognised by T cells.

But worth keeping an eye on that trend to slightly lower good responses in 🤰🏿&🤱12/12

Sorry, that should have said either "slightly lower" or "slightly less good"!