So much in fact that WHO and other major health organizations are fearing that the disease may reach pandemic proportions similar for the Spanish influenza outbreak of 1918/19 that killed an estimated 40 million people worldwide. Taking today’s population figures into account, that figure would be around 100 million today.

While medical laboratories are working non-stop to perfect an effective vaccine against the H1N1 virus, a number of scientific experts are fearing that a vaccine may not be effective enough against H1N1, which is now said to be much more deadly than normal “seasonal flu” viruses. As noted by a researcher named Yoshihiro Kawaoka of the University of Wisconsin, who wrote in the health journal Nature:

“When we conducted the experiments in ferrets and monkeys, the seasonal virus did not replicate in the lungs… The H1N1 virus replicates significantly better in the lungs.”

What this means, in layman’s language, is that the swine flu virus, as comparable with the 1918 Spanish flu virus, is capable of embedding itself deep within the lungs and causing severe pulmonary infections. This is also something much more serious than seasonal fu viruses which usually cause fewer problems with the lungs.

Another problem that could make swine flu more serious in many people is the fact that many more people suffer from obesity nowadays than in 1918; a condition that is said to cause more chances of complications than in people not overweight.

The WHO vaccines being developed are said to contain what are known as “live attenuated influenza viruses” which are simply live H1N1 viruses that have been weakened, but could still pose a serious threat to human health – especially in people who already suffer from chronic health problems, such as elderly people.

So what can one do to be better prepared this winter? On way of being better prepared against H1N1 flu virus is to watch you weight and participate in a daily exercise program, as well as eating a more natural diet. Making sure that you maintain a high level of vitamin D in your body, whether by adequate sunshine or by food supplements, as well as adequate sleep, should go along way to building up a “natural immunity” against all types of influenza viruses, including swine flu.