"With 11 or 12 vaccines required in the first 2 years of life, physicians and nurses need to be as up-to-date as possible and be prepared to educate parents," Dr. Gellin told Reuters Health in an interview during the meeting.

Dr. Gellin is an infectious disease specialist in Nashville, Tennessee, and the director of the National Network for Immunization Information. He is also an assistant professor of preventive medicine at Vanderbilt University.

The Network, which is sponsored by several medical professional societies, has established an online information center at http://www.immunizationinfo.org. The Network receives no financial support from any pharmaceutical company.

Some people and organizations have become distrustful of both vaccines and established medical sources, Dr. Gellin noted. "There are people in the US who are opposed to vaccines--there is a consumer movement--and parents have instant access to a lot of information about vaccines. Does that mean they're well informed? Perhaps not, because they may not know how to evaluate the information they receive."

In order to educate parents and yet speak to the general safety of vaccines, physicians and other healthcare professionals need to fully hear out parents' concerns and be prepared to educate them, he said.

"Remember the reason that these questions are even being raised," Dr. Gellin told Reuters Health. "Many diseases that were common and fatal are not part of young parents' collective experiences." The parents themselves may not have had measles or mumps, and they may have never met a polio survivor, he said.

"How do you keep an epidemic from reminding people of the value of vaccines? We need to know what the facts are and how to express them," he said. "We need to do the best job of answering questions, and we even need to elicit unasked questions. If parents leave the office with unasked questions, they will get their answers from other sources."