During the SARS-CoV-2 pandemic, novel and traditional vaccine strategies have been deployed globally. We investigated whether antibodies stimulated by mRNA vaccination (BNT162b2), including 3 rd dose boosting, differ from those generated by infection or adenoviral (ChAdOx1-S and Gam-COVID-Vac) or inactivated viral (BBIBP-CorV) vaccines. We analyzed human lymph nodes after infection or mRNA vaccination for correlates of serological differences. Antibody breadth against viral variants is less after infection compared to all vaccines evaluated, but improves over several months. Viral variant infection elicits variant-specific antibodies, but prior mRNA vaccination imprints serological responses toward Wuhan-Hu-1 rather than variant antigens. In contrast to disrupted germinal centers (GCs) in lymph nodes during infection, mRNA vaccination stimulates robust GCs containing vaccine mRNA and spike antigen up to 8 weeks post-vaccination in some cases. SARS-CoV-2 antibody specificity, breadth and maturation are affected by imprinting from exposure history, and distinct histological and antigenic contexts in infection compared to vaccination.

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Conditional gene regulation in Drosophila through binary expression systems like the LexA-LexAop system provides a superb tool for investigating gene and tissue function. To increase the availability of defined LexA enhancer trap insertions, we present molecular, genetic and tissue expression studies of 301 novel Stan-X LexA enhancer traps derived from mobilization of the index SX4 line. This includes insertions into distinct loci on the X, II and III chromosomes that were not previously associated with enhancer traps or targeted LexA constructs, an insertion into ptc, and seventeen insertions into natural transposons. A subset of enhancer traps was expressed in CNS neurons known to produce and secrete insulin, an essential regulator of growth, development and metabolism. Fly lines described here were generated and characterized through studies by students and teachers in an international network of genetics classes at public, independent high schools, and universities serving a diversity of students, including those underrepresented in science. Thus, a unique partnership between secondary schools and university-based programs has produced and characterized novel resources in Drosophila, establishing instructional paradigms devoted to unscripted experimental science.

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The prenatal environment may program health and disease susceptibility via epigenetic mechanisms. We evaluated associations of maternal trimester-specific intake of micronutrients with global DNA methylation (%5mC) and 5-hydroxymethylation (%5hmC) at birth in cord blood and tested for persistence into childhood. We quantified global %5mC and %5hmC in cord blood cells (n = 434) and in leukocytes collected in early (n = 108) and mid-childhood (n = 390) from children in Project Viva, a pre-birth cohort from Boston, MA. Validated food frequency questionnaires estimated maternal first- and second-trimester intakes of vitamin B2, vitamin B6, vitamin B12, folate, betaine, choline, methionine, iron, and zinc. Mean (SD) cord blood %5mC and %5hmC was 5.62% (2.04) and 0.25% (0.15), respectively. Each μg increase in first-trimester B12 intake was associated with 0.002 lower %5hmC in cord blood (95% CI: −0.005, −0.0003), and this association persisted in early childhood (β = −0.007; 95% CI: −0.01, −0.001) but not mid-childhood. Second-trimester iron (mg) was associated with 0.01 lower %5mC (95% CI: −0.02, −0.002) and 0.001 lower %5hmC (95% CI: −0.01, −0.00001) in cord blood only. Increased second-trimester zinc (mg) intake was associated with 0.003 greater %5hmC in early childhood (β = 0.003; 95% CI: 0.0004, 0.006). Second-trimester folate was positively associated with %5hmC in early childhood only (β = 0.08, 95% CI: 0.003, 0.16). Associations did not survive multiple testing adjustment; future replication is needed. Trimester-specific nutrients may impact various sensitive windows of epigenetic programming some with lasting effects in childhood. Further research is needed to understand the role of gene-specific epigenetic changes and how global DNA methylation measures relate to child health.