It turns out that the immunity reaction to the virus that comes first will stop any other virus from coming in. In the relatively warm autumn weather of September, the rhinovirus spread much more efficiently than the flu virus.
However, with colder weather now dominating, the flu virus is expected to get the upper hand, since it can be carried several metres through the air. Therefore, the Swine Flu epidemic that was expected in September might still be ahead of us. The question is whether the flu vaccine will stop it in time.