The House has passed a bill requiring youngsters' registration in a state immunization registry, unless parents elect not to participate.
The current system lets parents opt-into the registry, rather than opt-out.
The measure also seeks to modernize the registry and drew bipartisan support. It passed 92 to 55 on Wednesday, but was strongly opposed by tea party-backed representatives.
The information collected is only accessible to doctors. But critics worried what would happen if it fell into the wrong hands.
Its sponsor, Austin Democratic Rep. Donna Howard, asked critics, "What are you afraid would happen to the records?"
Longview Republican Rep. David Simpson said the bill would make the registry larger and could lead to the harassment of participants.
He asked, "Should parents take care of children or should the state?"