WATCH: Democrats sue feds over childhood vaccine overhaul

Democratic officials are calling the federal action unlawful.

Arizona Attorney General Kris Mayes said the suit names the U.S. Department of Health and Human Services and the Centers for Disease Control and Prevention as defendants.

The suit goes after “HHS Secretary Robert F. Kennedy Jr. and the CDC over their needless, confusing, scientifically unfound and unlawful revision of America’s immunization schedule,” said Mayes during a virtual press conference with California Attorney General Rob Bonta.

“Let me be clear about what happened here," Mayes told reporters. "In January, an acting CDC director with no medical or scientific background signed off on a so-called decision memo that stripped seven critical vaccines of their recommended routine vaccination status in favor of an unwarranted shared clinical decision-making recommendation that is confusing for parents and providers alike and difficult for providers to implement.”

Jim O’Neill was made acting CDC director after the August firing of Susan Monarez.

O’Neill’s “Decision Memo” was announced Jan. 5. This followed a Dec. 5 memo from President Donald Trump that directed the leaders of HHS and CDC to review how other developed nations structure their childhood vaccination schedules and consider “the scientific evidence underlying those practices.” According to HHS, the leaders of the National Institutes of Health, the Food and Drug Administration, and Centers for Medicare and Medicaid Services consulted with health ministries of peer nations, considered findings and later directed the CDC to move forward with implementation.

“The data support a more focused schedule that protects children from the most serious infectious diseases while improving clarity, adherence and public confidence,” said O’Neill in a January press release.

O’Neill has since been replaced by NIH Director Jay Bhattacharya.

In January, the CDC said it would continue to organize the childhood immunization schedule in three categories: recommended immunizations for all children, recommended immunizations for certain high-risk groups or populations, and immunizations based on shared clinical decision making.

The first category included shots for chickenpox, diphtheria, Haemophilus influenzae type B, human papillomavirus, measles, mumps, rubella, polio, pertussis, pneumococcal disease and tetanus.

Gone are recommendations for vaccines for the flu, hepatitis A and B, rotavirus, and RSV (respiratory syncytial virus).

Bonta said he was proud to be part of this lawsuit, adding that it's California's 59th suit against the Trump administration.

“HHS Secretary RFK Jr. and his CDC are flouting decades of scientific research, ignoring credible medical experts and threatening to strain state resources and make America’s children sicker,” said Bonta. “Their actions have been unconscionable, illogical and illegal.”

Examples offered by Bonta include Kennedy “blowing past appointment requirements” for the Advisory Committee on Immunization Practices, including that it be fairly balanced, and instead appointing “several anti-vaccine advocates and people without clear credentials” in immunization science.

The lawsuit is filed in the U.S. District Court for the Northern District of California.

The Center Square Tuesday contacted HHS, where spokesperson Richard Danker called the lawsuit a "publicity stunt."

"By law, the health secretary has clear authority to make determinations on the CDC immunization schedule and the composition of the Advisory Committee on Immunization Practices," said Danker, the assistant secretary for public affairs.

"The CDC immunization schedule reforms reflect common-sense public health policy shared by peer, developed countries," Danker said, answering The Center Square's question in an email Tuesday evening.

Earlier, HHS referred The Center Square to a previous statement that said the updated CDC childhood schedule “continues to protect children against serious diseases while aligning U.S. guidance with international norms.” HHS also claimed that many peer nations achieve high vaccination rates without mandates by relying on trust, education and strong doctor-patient relationships.

“HHS will work with states and clinicians to ensure families have clear, accurate information to make their own informed decisions,” said HHS.

With parties on both sides of the lawsuit pointing the finger at one another, The Center Square asked the Arizona Attorney General’s Office what people are supposed to think.

Richie Taylor, Mayes' spokesperson, said the recommendations being defended in this lawsuit are the product of decades of rigorous scientific research and peer review by thousands of independent experts.

“The public should trust the same evidence-based processes that eliminated polio, controlled measles until recently, and has protected public health for generations,” Taylor told The Center Square Tuesday. “The measles outbreaks now occurring across the country are an example of what happens when science is dismissed.”

In addition to those from California and Arizona, attorney generals involved in this lawsuit are Democrats from Colorado, Connecticut, Delaware, Maine, Maryland, Michigan, Minnesota, New Jersey, New Mexico, Oregon, Rhode Island and Wisconsin. Democratic Gov. Josh Shapiro of Pennsylvania is also participating.