Sex Differences in Influenza: The Challenge Study Experience.
The Journal of infectious diseases
washington; seattle; isb
BACKGROUND: Preclinical animal studies and retrospective human studies suggest that adult females have worse outcomes from influenza than males. Prospective studies in humans are missing.
METHODS: Data from 164 healthy volunteers who underwent Influenza A/California/04/2009/H1N1 challenge were compiled to compare differences between sexes. Baseline characteristics, including hormone levels, hemagglutination-inhibition (HAI) titers, neuraminidase-inhibition titers (NAI), and outcomes after challenge were compared. Linear and logistic regression models were built to determine significant predictor variables with respect to outcomes of interest.
RESULTS: Hemagglutination-inhibition (HAI) titers were similar between the sexes, but neuraminidase-inhibition titers (NAI) were higher in males than females at 4-weeks and 8-weeks post-challenge. Females were more likely to have symptoms (mean 0.96 vs 0.80, p=.003) and to have a higher number of symptoms (median 3 vs 4, p=.011) than males. Linear and logistic regression models showed that pre-challenge NAI titers, but not HAI titers or sex hormone levels, were predictive of all shedding and symptom outcomes of interest.
CONCLUSIONS: Females in our cohorts were more likely to be symptomatic and to have a higher number of symptoms than males. NAI titers predicted all outcomes of interest and may explain differential outcomes between the sexes.
Institute for Systems Biology
Giurgea, Luca T; Cervantes-Medina, Adriana; Walters, Kathie-Anne; Scherler, Kelsey; Han, Alison; Czajkowski, Lindsay M; Baus, Holly Ann; Hunsberger, Sally; Klein, Sabra L; Kash, John C; Taubenberger, Jeffery K; and Memoli, Matthew J, "Sex Differences in Influenza: The Challenge Study Experience." (2021). Articles, Abstracts, and Reports. 5171.