Oct. 16, 2009 (Baltimore) -- Researchers believe that there may be a link between a vaccine against cervical cancer and a rapidly progressive, fatal disease in two young women.

Both the timing of the symptoms and autopsy results “suggest a link between” the Gardasil vaccine and the fatal cases of amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, says Catherine Lomen-Hoerth, MD, director of the ALS Center at University of California San Francisco Medical Center.

With only two confirmed cases, “we don’t know for sure if it’s coincidence or if they’re connected [to the vaccine],” she tells WebMD. “We hope that by raising awareness, we will become aware of any other cases."

Pam Eisele, a spokeswoman for Merck & Co., which makes the vaccine, says the company cannot comment specifically on the cases as it has not seen the data.

“However, after carefully reviewing all the information available to us about reported adverse events, including reports of deaths, Merck does not believe these events have been caused by Gardasil,” she says.

The vaccine has been given to more than 7 million girls and young women nationwide.