The H1N1 swine flu virus appeared in the U.S. in April 2009 and never went away. After sweeping the globe, U.S. H1N1 swine flu cases surged as schools opened in the fall. What is H1N1 swine flu? What can we do about it? WebMD answers your questions.
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What made the difference? The power of the immune system. It's a network
that can help us avoid illness -- or sometimes become the underlying reason we
"The strength of our immune system is what makes the difference
between who gets sick and who doesn't. The one with the immune system
functioning below base-line normal has an increased risk of getting sick," says
Woodson Merrell, MD, director of integrative medicine at Beth Israel Medical
Center in New York City.
But is there anything you can do to keep your immune system from dropping
below par -- or increase its activity if it does?
Doctors say yes. And the secrets lie in understanding a bit about how the
immune system works -- and how your everyday life can stoke the fires of
In simplest terms, the immune system is a balanced network of cells and
organs that work together to defend you against disease. It blocks foreign
proteins from getting into your body. If a few happen to sneak by your
biological sentry, not to worry. With a powerful "search and destroy" task
force, your body deploys a host of additional immune cell forces designed to
hunt down these unwanted invaders and ultimately works to destroy them.
Fending Off Illnesses
"This entire system is known as the 'humoral' response. It's your body's
innate ability to manufacture antibodies that counter the infectious particle
-- allowing your body to eradicate it," says Phillip Tierno Jr., PhD. He's
director of clinical microbiology and diagnostic immunology at Tisch Hospital,
New York University Medical Center, and author of The Secret Life of
Antibodies are proteins which can identify normal "self" cells verses
foreign invading cells. They work as part of the immune system to destroy
abnormal or foreign cells.
This, he says, not only affects your ability to fend off common illnesses
like colds, the flu, or a stomach virus, but it can also play a role in
protecting you against catastrophic diseases like cancer or even heart
Additionally, we also have a second protective response known as the
"cell-mediated immune system." This immunity involves immune system cells,
rather than proteins, which are "helper" or "killer" cells. The cells help our
body create memory of past defense against disease protection.
"Your body recognizes that pathogen again, and immediately calls up the
memory of the previous infection and sets out to destroy the invader before the
disease develops," says neurophysiologist Carl J. Charnetski, PhD. Charnetski
is a professor of psychology at Wilkes University in Wilkes-Barre, Pa., and
co-author of Feeling Good Is Good For You: How Pleasure Can Boost Your
Immune System and Lengthen Your Life."
This mechanism is also the biologic behind vaccines for illnesses such as
measles, chicken pox, or hepatitis.
"The concept of inoculating us against diseases is based on deliberately
introducing a harmless amount of a pathogen so that our [immune] cells can
react, learn, and remember how to produce antibodies enough to fight it," says