The effect of cold exposure on influenza induced immune responses

The amount of people infected with the influenza virus varies throughout the
year, with most infections occurring during wintertime. From a large cohort
study we have learned that immune responses of isolated immune cells of
healthy volunteers during wintertime are less responsive to influenza
stimulation compared to those isolated during summertime. This seasonal effect
was specific to influenza and a handful of other pathogens, whereas most
pathogens showed no seasonal effect. The decreased responsiveness to influenza
in winter indicates that increased host susceptibility could be one of the
reasons for the seasonality of influenza infections. This susceptibility could
be influenced by various environmental factors. Two of the most significant
environmental differences between summer and winter are temperature and
precipitation. Cold in particular has been shown to be a modulator of the
immune system. However, the direct effect of cold on ex vivo influenza induced
immune responses has never been studied before. This study will investigate the
effect of cold exposure on immune responses induced by influenza. As a
reference we will also include a pathogen that does not show seasonal infection
rates. We speculate that cold exposure decreases the immune responses induced
by influenza, and that this effect is less pronounced in the non-seasonal
reference pathogen.

determine the effect of cold exposure on influenza induced immune responses

single arm interventional study

all participants exposed to a cold water bath. Before and after cold exposure
blood will be drawn to analyze changes in immune responses.

Burden of the study will include venapuncture before and after cold exposition
to a 16 degrees water bath of a duration of 4 minutes. Both are considered to
have minimum risk. There will be no benefit for participants.