“They are quite overt,” stated Dorit Reiss, a professor at UC Law San Francisco focusing on vaccine legislation and policy.
The organization was established and is led by William Lionberger, a chiropractor licensed in California since 1981, who previously operated a practice north of San Diego. Public records indicate he has also worked as a police officer in a community near Sedona. (Lionberger declined to participate in an on-the-record interview, and the organization did not respond to a series of inquiries from Undark.) Interviewers who have welcomed Lionberger on their programs characterize him as associated with America’s Frontline Doctors, an organization that opposed Covid-19 vaccinations and various public health initiatives while endorsing unproven treatments like hydroxychloroquine.
The Frontline Health Advocates website was first registered in March 2022, sharing a name reminiscent of America’s Frontline Doctors. By April of that year, the site was encouraging individuals to “Get your exemption now.” In a 2023 discussion, Lionberger mentioned having a “team of medical specialists” who “handle a variety of circumstances,” assessing clients for both “standard vaccine injuries and common vaccine exemption conditions.”
He remarked: “Nowadays, parents don’t even want their children to come close to standard vaccines.”
The group utilizes a couple of unique legal tactics. One of these involves establishing itself as a Private Ministerial Association. Online, some organizations that assist in forming such private associations describe them as offering unique First Amendment safeguards. A membership application document found on Frontline’s site presents the group as “a private, unincorporated ministry that functions as much as possible outside the authority of government entities, agencies, officers, agents, contractors, and other representatives, as protected by law.”
An additional tactic is to invoke federal disability legislation. In the 2023 interview, Lionberger boasted that they relied on “the most formidable tool you can use against discrimination”—specifically, federal protections. A promotional video featured on the Frontline site makes a comparable assertion, promoting waivers “backed by protections under US federal laws.” Undark acquired three nearly identical exemption letters sent to New York families in 2024. In these documents, Frontline contends that the client’s need for a medical exemption is safeguarded under the Americans with Disabilities Act, or ADA, which ensures specific accommodations for individuals with disabilities and other medical requirements.
