Lisa Schryver Ericzon's daughter, Jessica F., died two years ago, and Ms. Ericzon says she believes the Gardasil vaccine was the cause. Ms. Ericzon, Omar, has spent the past two years researching the vaccine and connecting with other parents, in an effort to get her concerns about the vaccine heard.

"We're getting along. We take it day by day," Ms. Ericzon said. "I've done a lot of research since Jessie died. We cannot prove it, but it seems that there are way too many girls who have been injured or died after getting this vaccine."

Ms. Ericzon returned home after work Feb. 22, 2008, to find Jessica, 17, dead on the bathroom floor. It was two days after receiving her third dose of Gardasil. Jessica had been complaining of pain in the back of her head since receiving the shot, Ms. Ericzon said.

She said she believes that Gardasil was to blame for Jessica's death, and during her research on the vaccine, she has tried to contact agencies like the U.S. Food and Drug Administration to voice her concerns.

Gardasil, which is produced by Merck & Co., is a vaccination against four types of human papillomavirus, which can lead to cervical cancer. Gardasil is administered in a three-shot series to females between the ages of 9 and 26.

Jessica's autopsy results didn't yield a specific cause of death, and toxicology reports were inconclusive. After performing the autopsy, Jefferson County Medical Examiner Dr. Samuel A. Livingstone reported the death to the federal Vaccine Adverse Events Reporting System, or VAERS.

But on the VAERS Web site, people who view the vaccine data are cautioned that the adverse events can be submitted by anyone, including health care providers, patients and family members.

"A report to VAERS generally does not provide sufficient basis for concluding that the identified vaccine caused the adverse event described," the Web site reads.

The Jefferson County Public Health Service has administered 1,211 doses of Gardasil since 2007. It has not reported a reaction to Gardasil to VAERS, said Stephen A. Jennings, public health information officer.

"There haven't been any deaths that I know of that have a proven link to the vaccine," he said. "I know that because we're advised to continue administering the vaccine by the New York state Health Department and the (U.S.) Centers for Disease Control and Prevention."

But Ms. Ericzon said she believes Gardasil was the cause of Jessica's death. She has used the Internet to connect with mothers from all over the country who have concerns similar to hers about Gardasil. One woman is a north country resident.

Karen K. Spooner, Pillar Point, sent Ms. Ericzon an e-mail when she heard about Jessica's death. Mrs. Spooner's daughter, Alison L., began experiencing flu-like aches and pains and numbness in her arm after receiving her second dose of Gardasil.

"Alison connected the symptoms with getting the shot," Mrs. Spooner said. "We went back to the doctor and filed paperwork with Merck about the reaction. She didn't have the third shot."

Ms. Ericzon and Mrs. Spooner have gone back and forth, discussing the vaccine and comparing the symptoms their daughters experienced.

Ms. Ericzon and her boyfriend, Timothy Hall, spend hours every week researching the vaccine, its ingredients and possible side effects on the Internet. Her ultimate goal is to see the vaccine taken off the market, but she doesn't think that will happen anytime soon, she said.

"It will take scientific proof to get Merck to remove Gardasil from the market, and there are no doctors I know of who have said something is wrong with the vaccine," Ms. Ericzon said. "It's going to take someone much more high profile than us to get that to happen."

But she said she doesn't see an end to her efforts anytime soon and plans to keep researching and reaching out to other parents.

"There's strength in numbers, and now there are other people who are demanding information too," she said. "I felt so alone when Jessie passed away. Now I know that I'm not alone."