A total of 92% of echinacea recipients and 95% of placebo recipients were infected. Colds developed in 58% of echinacea recipients and 82% of placebo recipients (P=.114, by Fisher's exact test). Administration of echinacea before and after exposure to rhinovirus did not decrease the rate of infection; however, because of the small sample size, statistical hypothesis testing had relatively poor power to detect statistically significant differences in the frequency and severity of illness.

Echinacea

Health conditions analyzed in this study

Common Cold

1 supplement Moderately Positive Echinacea

Functions related to this study

Immunity

1 supplement Moderately Positive Echinacea

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Body systems related to this study

Respiratory System

1 supplement Echinacea