AUGUSTA, Maine — The Legislature’s Health and Human Services Committee on Monday split along party lines on a bill that would require doctors and their staff members disclose vaccine ingredients to parents before they agree to have their children immunized.

The committee voted 6-4 against the bill, LD 754, after a debate that centered on concerns that such a requirement could turn parents off to vaccinating their children and parents’ right to know what’s being injected into their children’s bodies.

The Health and Human Services Committee weighed the disclosure requirement a week after the proposal, sponsored by Rep. Andrea Boland, D-Sanford, ran into stiff opposition from doctors at a public hearing.

Boland’s legislation comes as vaccine rates in Maine and elsewhere are slipping amid growing concerns about the ingredients in vaccines and related effects on health. Doctors and their representatives who testified at the public hearing said a declining vaccination rate is a cause for concern, and as a result, Maine is seeing communicable diseases such as pertussis, also known as whooping cough, more frequently.

Opponents on Monday said parents who want the information can ask their children’s doctors or look up the information online. Rep. Richard Farnsworth, D-Portland, said the required disclosure of ingredients — whose meaning is unknown to most people without specialized education — could raise unnecessary alarm among parents.

“This is an anti-vaccine bill,” said Rep. Ann Dorney, D-Norridgewock, who is a family physician. “We’re going to be discouraging parents from vaccinating their children, or that’s going to be the effect of the bill.”

But Rep. Deborah Sanderson, R-Chelsea, said disclosing ingredients to parents before they agree to have their children vaccinated would simply be “informed consent.”

“Why can’t this information be provided to parents at the time of vaccination, or maybe prior to, so they have the time to go look and see what’s in the medications and vaccinations that are going to be injected into their child?” she said.

Rep. Heather Sirocki, R-Scarborough, said the disclosure requirement could present an opportunity for conversations about the importance of vaccines among parents and pediatricians.

The proposal next moves to the full Legislature. Boland sponsored a similar bill two years ago that failed in both the House and Senate.