As an immunologist working on pregnancy, I know people have a lot of questions about the #COVID19 #vaccine, #fertility, #pregnancy and #breastfeeding. 💉🤰🏻🤱🏾. This explainer summarises what we know so far (it's reassuring!) and I update it regularly.

RT @NatRevImmunol: Vaccination in pregnancy to protect the newborn

PS. Popping back to post this because *so many* of you tweeple have asked about it over the years, so I wanted to be sure to share here! But I am mostly over at 🦋now - same handle!.

Finally, why did we do all this? Because ppl living with.#LongCOVID and #MECFS asked us to! Big thanks to collaborators @HarryLeeming and @RorPreston from @visible_health who made it possible. Thanks to the MRC for funding. And congrats to lead author Abi Goodship! 5/5.

But a caveat! These data don’t show combined hormonal contraception *causes* fewer crashes - perhaps a 3rd factor we haven’t measured influences both contraception and crashes. But certainly this suggests contraception is worthy of further investigation as a therapy. 4/.

Our finding that combined hormonal contraception is associated with fewer crashes could inform use of contraception in people living with #LongCOVID #MECFS. (Progestin only contraception doesn’t do this.) 3/.

Our findings on symptoms over the menstrual cycle chime with survey reports, but use of app data reduces recruitment and recall bias. Knowing they are more vulnerable to crashes during menstruation could help people plan less strenuous activities during their period. 2/.

948 users prospectively entered #MenstrualCycle.& #LongCovid #MECFS symptom data into tracking app @visible_health. 👉🏻 Crashes more likely during menstruation . 👉🏻 Crashes less common in people taking combined hormonal contraception . 🧵.

Link….

I plan a thread with more info and nuance later today. You’ll find that on 🦋. 5/5.

I certainly do not envy the JCVI, having to make these decisions!. But what hasn’t changed is the view of the MHRA, which decides whether vaccines are safe and (medically) effective. They continue to back COVID vaccines in pregnancy, and you will be able to buy one privately. 4/.

There are arguments that this is the wrong decision. Perhaps it is worth spending ~3k to avoid one baby being hospitalised. And/or perhaps there are other benefits of extending the offer that have not been factored into this analysis. 3/.

With prices rising to £25/dose next spring, and an estimated 13,000 doses (£325,000) needed to prevent one baby being hospitalised, it is thought the money could be better spent elsewhere. 2/.

The JCVI will not offer COVID vaccines in pregnancy in Autumn 2025. Does this mean they shouldn’t have been offered before?. No!. The JCVI decides if vaccines are cost-effective enough to be offered free. Prices ⬆️ so they have decided no… 1/.

Happy The Clock in the Car is Right Again Day to all who celebrate.

When I was working on the liver, I never heard 50-year-old tropes about it quoted. Nor did people feel they had an instinctive understanding of how its immunology must work. Why is it different for the placenta? 🤔.

RT @chrischirp: Important 🧵on our new peer-reviewed paper: . The pandemic is as bad as it ever was for babies - in year to Aug 2023, 6,300….

🤔 Should we change the timing of COVID vaccination in pregnancy to maximise protection of babies after birth, rather than during pregnancy?. This paper (and lots of pediatricians who have got in touch!) argue that we should. And I’m starting to agree with them…. 3/3.

… and of the nine babies who died, none were born following COVID vaccination in pregnancy. 👶🏼 This adds to the extensive evidence that COVID vaccination in pregnancy protects newborns from COVID. 2/.