DENVER -- A Colorado mother says what you don't know about the HPV vaccine can hurt you.

Leslie Zimmers' daughter, Sarah, got her first shot to prevent cervical cancer a few weeks ago. It should have been a routine vaccination, along with a few other booster shots Sarah was required to get to attend school in Colorado.

But moments after getting the injection, things went terribly wrong.

"It literally felt like a lead weight was in my veins," Sarah said. "All of a sudden, the room started getting dizzy and I was like, 'I don't feel good' and then I went out."

Sarah passed out.

"I noticed that she wasn't breathing and her face was very white, her mouth was white," said Leslie.

Paramedics rushed Sarah to the emergency room. She stayed there for hours as doctors worked to keep her blood pressure up.

"It was upsetting," Leslie said.

But even more upsetting was what Leslie found on the Internet later that day when her daughter was finally sent home: studies showing that at least 29 people had died shortly after getting the vaccine.

Doctors said that number can be deceiving.

"It is a safe vaccine to give to our young girls," said Dr. Catrina Bubier.

Bubier said 16 million women have received the HPV vaccine and 96 percent of them had no adverse reactions. Most of the 29 deaths appear to be completely unrelated to the vaccine, Bubier said.

Bubier said hospitals are required to report any death that happens within two weeks of a patient receiving a vaccination, even if the death is something as random as an unrelated car accident.

"If it happens within 14 days of the vaccination, then it has to be reported," Bubier said.

The Centers for Disease Control, the Food and Drug Administration and Bubier all maintain that the vaccine is safe.

"I have a 5 and a half year old daughter and when she's of age, I plan on giving her the vaccine," Bubier said.

Bubier said there is some debate about whether the cervical cancer vaccine should be administered alone or with other shots. She said at hospitals, women are given the shot alone.

Sarah received her shot with other shots.

Doctors said it is important for parents to know that there are side effects with the cervical cancer vaccine, but they are generally not severe.

"Many women will complain of soreness at the injection site, redness at the injection site," said Bubier. "Rarely is there dizziness or fainting associated with the vaccine."

Bubier said some patients also experience fever and that is not uncommon for teenagers to sometimes faint after getting a shot, no matter the vaccination.

Still, the Zimmers said hospitals, clinics and doctors should do more to educate parents about the serious risks of the cervical cancer vaccine, even if instances of fainting or death are rare.

"They need to have far more information than they do," said Leslie.