美国有线新闻 CNN 美国即将进入流感季 医生建议接种疫苗（在线收听）

In the U.S., flu season starts next month. It's a time when flu epidemics often break out in the country. The Centers for Disease Control says it can last from October to May. This year, a group of American Pediatrician says flu mist, a nasal spray, designed to prevent the flu, should not be an option.

The reason: this summer, the CDC said it was not very effective.

Doctors are still recommending that Americans get the flu shot, just not the mist. They say everyone six months and older should be vaccinated and that that's the best protection against getting the flu. Vaccinations are not 100 percent effective. There's a chance you get the shot and still catch the flu. You just wouldn't get it from the shot itself.

DR. SANJAY GUPTA, CNN CHIEF MEDICAL CORRESPONDENT: Let me try and settle this flu shot thing, although I'm sure it's going to keep coming up again and again.

SUBTITLE: Debunking flu myths.

GUPTA: You can't get the flu from the flu shot. It's a dead virus, it can't actually cause flu. Why do people feel sort of crummy afterward?

It's because the flu vaccine is actually working, making your immune system fire up, get ready and recognize it, if it actually sees the flu, how to kill it.

No, it's not 100 percent fail safe. But it's still going to offer a lot of protection, so you are not going to be as sick as likely to get sick or if you do get sick, have a shorter duration.

OK, so if you are like me, your mom probably said don't go outside in the cold without your hat on, you are going to catch the flu. You can't catch the flu from just simply being outside in the cold.

But it does raise the question, why are there so many more flu cases in the winter months? You are likely to stay indoors more. So, if one person is sick, more people are likely to get sick.

The sun is lower in the sky, and as a result, you have less Vitamin D actually being produced in your body. Your immune system starts to get suppressed a little bit. You are more likely to get sick with the flu.

Winter months tend to be lower humidity. Viruses like the flu virus they like lower humidity. They are likely to live longer.

So, your mom may have been right: I mean look, moms are always right, but maybe not for the reasons you originally thought.