By Dr. Jeff Daniels EBS Medical Columnist

The human immune system is a remarkable piece of work. Not only does it protect us against all sorts of invading organisms – viruses, bacteria, fungi and parasites – it also eliminates our own cells that turn cancerous.

We know that immunity is not perfect because we all get infections and some of us develop cancer, but throughout a lifetime – now 85 to 90-plus years for most Americans – the immune system is constantly working to keep us disease free.

I studied immunology intensely during my fellowship training in New York, and to me the most fascinating aspect of our immune system is how it produces billions of cells and molecules to fight an immense array of pathogens. It does so by splicing and combining a small amount of our DNA in various branches of the immune system then mass-producing specific defenses.

When germs invade our body, the first line of defense is a broad attack not aimed specifically at that one microbe. Over eons, this has evolved and proven effective in slowing down the pathologic process. That gives the immune system time – about a week or two – to mount a calculated, specific attack and successfully dispose of the infection. Many of the common illnesses we deal with could be fatal without a specific immunologic defense.

Timely vaccinations are important. By giving our immune system a chance to gear up before an attack we can limit, or virtually eliminate, a specific infection if we’re exposed to others with that disease.

Many of you are too young to remember some common diseases that are now preventable and rarely mentioned. Polio, before Jonas Salk developed a vaccine in the late 1950s, killed or paralyzed thousands of people every year. Measles, which until a vaccine was introduced in the early 1960s, infected almost every American child under the age of 15, and accounted for about 450 deaths per year in otherwise healthy children. German measles, also known as rubella, caused deafness and other birth defects in kids.

Very few vaccines are perfect, and only one disease prevented by a vaccine has been completely wiped off the face of the Earth. Smallpox was the first human disease to have a preventative vaccination. Other vaccine-preventable diseases still lurk, often in less developed countries, with the potential of sneaking back and infecting people who have not been vaccinated, such as measles did last year.

Consider this: Researchers at the University of California, San Diego showed that a child with a healthy immune system can effectively process up to 100,000 different immunological challenges at once. Most vaccines we use contain dozens, maybe hundreds of unique molecules to challenge the immune system and stimulate a protective response.

Since the Centers for Disease Control and Prevention recommends only 14 vaccines, to be administered over a two year period, those who worry about children getting too many vaccinations in short periods of time shouldn’t be so concerned.

I’ll have more to say about the importance and safety of vaccines in future columns.

Dr. Jeff Daniels has been practicing medicine in Big Sky since 1994, when he and his family moved here from New York City. A unique program he implements has attracted more than 700 medical students and young doctors to train with the Medical Clinic of Big Sky.