CAMDEN, NJ (CBS) — We keep hearing how swamped area emergency rooms have been with people sick with the flu. So, why aren’t all the health care workers suffering from the virus?

The local emergency room has been overflowing with people coughing, sneezing complaining of body aches says Dr. Alfred Sacchetti, Chief of Emergency Medicine at Our Lady of Lourdes Medical Center in Camden.

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He says of the nearly 100-doctors, nurses and others in the ER…only two have come down with the flu so far and he credits hospital policy.

“All of our staff have had mandatory vaccinations going back years, so that we have kind of built up a library of antibodies against all the variations of the flu,” he said. “That’s led to the tremendous ability of our staff to resist what’s become a nasty flu season.”

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He also says his co-workers are pros at practicing good hygiene.