PHILADELPHIA (CBS) — With the frigid weather setting in, more people will be inside which is when respiratory infections are more likely to spread.

Today there are renewed warnings about the widespread misuse of antibiotics.

Mackenzie Meyer has a sore throat and a cough.

“It persisted for 5 days, I decided to stop in and make sure it wasn’t strep,” she said.

Her doctor determined it was not strep throat, which is a bacterial infection, but more likely a virus which is not treated with antibiotics.

“Viral infections don’t respond to antibiotics because antibiotics are targeted specifically at bacteria,” Dr. Henry Fairmow explained.

Fairmow is an Infectious Disease Specialist at Cooper Univerisity Hospital.

“So if you take an antibiotic for a viral infection, it’s not gonna help you,” he said.

In issuing new warnings about overuse, the American College of Physicians together with the CDC warn that 50% of antibiotic prescriptions for respiratory illnesses may be unnecessary.

“The goal of this is to protect antibiotic overuse which causes antibiotic resistance, which is literally killing people in this country,” Dr. Janette Newsheiwat, an infectious disease specialist, said.

If doctors know there’s a problem with antibiotic resistance, why do they keep prescribing so many antibiotics that aren’t necessary?

“Because patients expect them, and because we really don’t have anything else that works at that well, not that antibiotics get rid of their symptoms, but people believe they’re going to get better with an antibiotic,” she said.

Instead of antibiotics, Mackenzie was told rest would be more helpful.

“I want to make sure that when I’m really sick, my body will be able to fight it off and the antibiotics will be able to help,” she said.