Influenza A is more likely to appear between early winter and the beginning of spring in areas that have distinct seasons. Influenza B can appear any time of the year. Both types begin to show symptoms within a week of exposure to the virus. read more
Influenza B can cause outbreaks of seasonal flu but they occur less frequently than outbreaks of influenza A. Typically, two strains of influenza A and one strain of influenza B are included in the seasonal flu vaccine. read more