Homeland Security Secretary Janet Napolitano says people should expect "a big influx" of swine flu cases this fall and brace for it as best they can.

Napolitano also said in a nationally broadcast interview Wednesday that many cases are likely to surface before a vaccine for H1N1 is available, probably no earlier than mid-October.

She said "the best things we all can do are the very simple things" like thorough and frequent hand-washing and coughing into the sleeve. Napolitano appeared on NBC's "Today" show a day after President Barack Obama got a briefing on federal plans for the virus and said that people should be prepared but not alarmed.