The debate over the safety of childhood vaccinations continued at the State Capitol on Monday, when a House committee heard conflicting testimony over a plan to mandate two more vaccines.

Shannon Duffy Peterson of Sleepy Eye told legislators that she lost her 5-year-old daughter to complications related to chickenpox in 2001, a death that she said could have been averted with a chickenpox vaccine. She supported a vaccine expansion.

Stephanie Lee of Finlayson told legislators that her 2-year-old daughter died after developing seizures and medical complications shortly after receiving her infant immunizations. Lee opposed more vaccine requirements.

Meanwhile, state health officials told the House Health and Human Services Committee that serious negative reactions from vaccines were rare. But vaccine opponents said that parents are discouraged from reporting reactions, and that the state Health Department is not capturing all the problems.

Such was the debate over the plan to recommend that children receive vaccines for chickenpox and pneumococcal bacteria, the leading cause of meningitis. The Health Department presented the plan to a Senate committee last week. The Legislature does not have the authority to halt the plan, but it can make changes to it.

The plan would:

• Require chickenpox vaccinations for children in child care, age 15 months to 2 years, as well as school-age children in kindergarten and seventh grade. Children who already had the disease would be exempt.

• Require a vaccine for pneumococcal bacteria, the most common cause of bacterial meningitis in young children, for children in child care who are between two months and 24 months old.

Thirty-five states already have a chickenpox vaccination requirement in their school laws, said Kristen Ehresmann, who oversees immunization programs at the Minnesota Health Department. About three states have requirements for the pneumococcal vaccine, she said.

Additionally, she said, parents have the option of not vaccinating their children. However, in such cases, that information must be reported to school nurses so the school would know which children were at risk of certain diseases.

Dale Thompson, representing the Immunization Action Coalition, a St. Paul nonprofit that produces educational materials on vaccines, supported the Health Department plans.

"With the exception of safe water, no other health intervention -- not even antibiotics -- has had such a tremendous effect on the reduction of disease and the improvement of health as has immunization," Thompson said.

But Jerri Johnson, of the Minnesota Natural Health Coalition, said there is a long history of adverse reactions to immunizations, including seizures and possibly autism.

New vaccines should be recommended only after being adequately tested for safety and efficacy, she said.

"We have a good debate in this country on the smallpox vaccine," Johnson said. "This could be a great model for our infant vaccination program."

Members of the committee offered different views on the issue. Rep. Thomas Huntley, DFL-Duluth, said it was crucial to understand the difference "between cause and correlation." There may be a correlation between the vaccines and health problems but not necessarily a cause, he said.

Committee Chairwoman Lynda Boudreau, R-Faribault, was more skeptical about the need for more vaccines.

"I'm concerned the way the data is collected, whether it is skewed," she said. "And I'm concerned about the comment [made by a parent] that she couldn't get a physician to give her a medical exemption."

Boudreau said she is considering introducing legislation to strengthen the reporting and analysis of adverse reactions to immunizations.

-- Jean Hopfensperger is at hopfen@startribune.com.