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Published on: July 6, 2014
Menstrual cycle phase and its association with COVID-19 vaccine outcomes among period tracking app users
Poppy Alexandra Cooper1, Emily R Boniface2, Blair G Darney2
1LSHTM (London School of Hygiene & Tropical Medicine), London, UK.
Abstract:
Despite known hormonal influences on immune function, the impact of menstrual cycle phase on vaccine outcomes remains unexplored. Using prospectively tracked cycle data from the Clue period tracking-app, matched with an in-app survey of 1474 women, we compared self-reported COVID-19 vaccine outcomes between follicular-phase (estrogen-dominant) and luteal-phase (progesterone-dominant) vaccinated women. Side effect presence, severity and number were analysed using binary, ordinal, and negative binomial regression respectively, and post-vaccination time to infection (67-372 days) via Wilcoxon rank-sum test. Follicular-phase vaccination was associated with 35% higher odds of any self-reported side effects (OR: 1.35, 98.3% CI: 1.01-1.79) compared to luteal-phase vaccination. Median time to infection was 35 days longer following follicular-phase vaccination (200 [140-237] vs 165 [107-210] days, p = 0.05), though infection numbers were limited. These findings suggest menstrual cycle phase warrants consideration in sex-based immunity research and may inform future research on vaccination and personalised health strategies.
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