COVID-19 mRNA vaccination generates greater IgG levels in women compared to men.

<bold>Question: </bold>Is antibody response to COVID-19 mRNA vaccination similar in women and men?<bold>Findings: </bold>In a community cohort without prior COVID-19 infection, the first vaccine dose produced higher IgG levels and percent inhibition of spike-ACE2 receptor binding, a surrogate measure of virus neutralization, in women compared to men (7.0µg/ml; 51.6% vs 3.3µg/ml; 36.4%). After two doses, IgG levels remained significantly higher for women (30.4µg/ml) compared to men (20.6µg/ml), while percent inhibition was similar (98.4% vs 97.7%).<bold>Meaning: </bold>Sex-specific antibody response to mRNA vaccination informs future efforts to understand vaccine protection and side effects. [ABSTRACT FROM AUTHOR]