WASHINGTON - Vaccine industry officials helped shape legislation behind the scenes that Senate Majority Leader Bill Frist secretly amended into a bill to shield them from lawsuits, according to e-mails obtained by a public advocacy group.

E-mails and documents written by a trade group for the vaccine-makers show the organization met privately with Frist's staff and the White House about measures that would give the industry protection from lawsuits filed by people hurt by the vaccines.

The communications were made public in a report released this week by the group Public Citizen. Its study follows a February story in The Tennessean that Frist, along with House Speaker Dennis Hastert, R-Ill., ordered the vaccine liability language inserted in a defense spending bill in December without debate and in violation of usual Senate practice.

The group, called the Biotechnology Industry Organization, wanted such language in the bill, the e-mails reflect.

"At Senator Frist's staff's request, this morning, BIO (Tom and I) participated in a meeting with three other industry representatives (Sanofi and an outside counsel who works for both Pfizer and Roche, I believe), administration staff (HHS, DoJ and WH Leg Affairs), and Liz Hall to further discuss liability," BIO official Dave Boyer wrote in a November e-mail obtained by Public Citizen.

In a written statement, Frist spokeswoman Amy Call stated that the senator had promised publicly to include the vaccine liability protection in the defense spending bill. She did not address the issue of the influence of industry lobbyists.

The statement points out that the Public Citizen board includes prominent trial lawyers and liberals. "Trial lawyers oppose these provisions because it will strip them of the ability to line their pockets at the expense of the American public," Call said.

Frist and the White House reached out to the industry, according to the communications cited by Public Citizen, and Boyer, chief lobbyist for the industry group, was asked to provide an analysis of draft legislation.

The group asked that the legislation make clear that a vaccine maker could only be successfully sued if "willful misconduct" on its part were proved. The law includes that standard and says a company is protected from claims of negligence or recklessness.

The analysis, which Public Citizen quoted from, included BIO's concerns that the draft bill would have still allowed people hurt by vaccines to get jury trials.

"The lack of any restriction on jury trial is problematic," the analysis said. "Where injured parties have no other avenue for relief, juries are likely to find ways to award damages."

In another e-mail, Boyer described a meeting in which a deputy of Bush strategist Karl Rove said it was "important to the President that a bill move this year," and said "they had invited industry to discuss what they understood to be a few key remaining points" of contention.

"The intimacy of this, we think, is quite unusual," said Joan Claybrook, president of Public Citizen, about the relationship between the organization's lobbyists, Frist and the Bush administration. "We think it is an interesting case study of how the inside operation works in Washington."

In a January interview with The Tennessean, Frist denied the vaccine liability provisions were added improperly. Later, when others challenged his version of events, Call simply restated Frist's commitment to protecting people from a bioterror emergency.

Frist and other backers say the law is needed to boost the number of vaccine makers. Vaccine shortages during last year's flu season along with fears of a pandemic of bird flu or a bioterror attack have prompted interest in building up the country's lagging vaccine industry. The legal protections kick in only when the secretary of health and human services declares a public health emergency.

Alan Eisenberg, executive vice president for the Biotechnology Industry Organization, said the group's "staff acted with the utmost integrity and professionalism, as they do on all issues."

"BIO staff regularly comment on proposed legislation from, and meet with, Democrat and Republican lawmakers and their staffs alike all the time," Eisenberg said.