But what do you know for sure about the virus?
On "The Early Show" Friday, CBS News Medical Correspondent Dr. Jennifer Ashton separated flu facts from fiction to help you be better prepared for the months ahead:
1. The H1N1 flu vaccine will give me the flu.
This is a common myth that doctors battle every year. And the H1N1 flu is being made the same way that seasonal flu is manufactured. The flu vaccine is created from killed virus, so there is no way to transmit flu from the vaccine.
Flu season coincides with the cold season so people frequently confuse the common cold with the flu. Also, in some cases, people who get a flu shot can still get the flu, but they may get a much less severe form of the illness and, most importantly, they'll have a decreased risk of flu-related complications -- especially pneumonia, heart attack, stroke and death -- to which older adults are especially vulnerable.
2. Wearing a mask will protect me from flu.
Except in certain health care settings, the Centers for Disease Control and Prevention (CDC) does not recommend wearing a face mask. They have a lot of shortcomings for infection control. They're only good for a short period of time and as soon as they get moist, they become ineffective. They also do not fit tightly enough around the face to prevent small infected droplets to get through. The best advice is that if you're sick, stay home. Stay away from sick people and make sure to keep your hands clean and practice good cough etiquette by coughing into your sleeve.
3. Hand sanitizer is as effective as washing my hands.
They are an effective way of cleaning your hands of germs. Doctors use them and they're commonplace in hospitals.
Ashton referenced the CDC, saying, the influenza virus is destroyed by heat. In addition, several chemical germicides, including chlorine, hydrogen peroxide, detergents (soap), iodophors (iodine-based antiseptics), and alcohols are effective against human influenza viruses, if used in proper concentration for a sufficient length of time. Wipes or gels with alcohol in them, for example, can be used to clean hands. The gels should be rubbed into hands until they are dry.
4. I am sneezing, have a sore throat and a cough, so I have H1N1 flu.
No, you need to also have a fever. Coughing and shortness of breath are common symptoms, but also vomiting, fatigue, muscle soreness and diarrhea.
Ashton cited the CDC saying the symptoms of novel H1N1 flu virus in people are similar to the symptoms of seasonal flu, although vomiting and diarrhea has been reported more commonly with H1N1 flu infection than is typical for seasonal flu.
The CDC studied the hospital records of 268 patients hospitalized with novel H1N1 flu early on during the outbreak. In this early subset of cases with significant clinical data, fever (93 percent) and cough (83 percent) were the two most reported symptoms. This is not surprising since cough and fever were part of the case definition. Other symptoms were shortness of breath (54 percent), fatigue/weakness (40 percent), chills (37 percent) and myalgias, also known as muscle soreness (36 percent).
5. If the rapid flu test comes back negative, that means I don't have H1N1 flu.
The CDC reports that many of the rapid diagnostic tests may miss many cases of the H1N1 flu, Ashton said. The overall sensitivity ranged as low as 40 to 69 percent. So, she said, the first result may not be the most accurate. The CDC recommends that clinicians use their judgment based on the patient, and prescribe Tamiflu if necessary.
For more information on the H1N1 virus, learn more at the CDC.