MBL has been shown to strongly bind S. aureus (31) and susceptibility to fatal S. aureus infection due to MBL defi ciency has been convincingly demonstrated in murine models (32) . Phase I clinical trials of MBL replacement therapy indicate that this therapy is well tolerated and effective at improving MBL defi ciency in healthy persons (33) . Reports of MBL replacement therapy administered to severely ill persons (34) (35) (36) or to patients with S. aureus sepsis (37) suggest that therapy can improve clinical conditions, although results of these studies were mixed, and in some cases, clinical improvements were temporary. The clinical implications of MBL replacement therapy for infl uenza treatment or prevention are unknown. Among persons with fatal cases, we observed an increased risk for sudden death in carriers of the variant allele of TNF rs1800750. We are unaware of previous literature reporting a similar association; there is no obvious biologic mechanism to explain the fi nding. The TNF rs1800750 variant is in linkage disequilibrium with other TNF variants (http://pga.gs.washington.edu), some of which (including TNF rs361525) have been associated with increased TNF serum levels. Therefore, it is possible that the observed association may be due to linkage disequilibrium with unmeasured polymorphisms that are the causal variants, and more exhaustive analysis of TNF variants is worthy of future study.