"Absolute humidity, for reasons that remain undetermined, is affecting how long the virus remains viable, " he says.

CNN: Study: Humidifiers may help fight flu

Absolute humidity, on the other hand, refers to the actual amount of water vapor in the air regardless of saturation.

CNN: Study: Humidifiers may help fight flu

Some included information on relative humidity, which he converted to absolute humidity.

CNN: Study: Humidifiers may help fight flu

Shaman converted the guinea pig data from relative humidity to absolute humidity and found the link between air moisture and flu spread got much stronger.

CNN: Study: Humidifiers may help fight flu

For example, in the wettest possible absolute humidity, less than 20 percent of the virus was still viable after an hour, while at the driest conditions 80 percent of the virus was still capable of making someone sick.

CNN: Study: Humidifiers may help fight flu