Pledging communication about vaccines that will be “grounded in science, not ideology,” the governors of California, Washington and Oregon announced Wednesday they will form a West Coast Health Alliance to begin coordinating public health guidelines separate from the US Centers for Disease Control and Prevention.

“The new alliance represents a unified regional response to the Trump Administration’s destruction of the U.S. Centers for Disease Control and Prevention’s credibility and scientific integrity,” the trio announced in a news release issued by California Gov. Gavin Newsom’s office.

The move comes a week after the CDC Director Dr. Susan Monarez was ousted by the White House after clashing with US Health and Human Services Secretary Robert F. Kennedy Jr. on vaccine policy. Four top agency leaders promptly announced their resignations in solidarity.

Lawyers for Monarez said she was “targeted” after she “refused to rubber-stamp unscientific, reckless directives and fire dedicated health experts.”

In a statement, the White House said Monarez was “not aligned with the President’s agenda of Making America Healthy Again.”

Even before last week’s exodus of top leadership from the CDC, some state and local health departments had begun looking for ways to end the reliance on the CDC and its advisers for their vaccine policies.

“We are seeing state-led efforts of different kinds emerging as their leaders prepare to protect their residents from federal guidelines not based on sound scientific evidence,” said Dr. Kelly Moore, who is president and CEO of the nonprofit Immunize.org.

Many states have laws guided by vaccine recommendations issued by the CDC’s Advisory Committee on Immunization Practices, or ACIP, committee. But after Kennedy abruptly fired all 17 experts on that committee and replaced them with seven of his own picks, many of whom have histories of casting doubt on vaccines, states began looking for ways to divorce their policies from those of the CDC.

Nine states, for example, have banded together to create the Northeast Public Health Collaboration, which is staffed by state and city health officials. The group is organized into committees, and their work has intensified quickly in response to shifting federal health priorities and deep cuts to health agencies, according to a person familiar with the group who was not authorized to share the details of their plans.

“They’re specifically looking at how, as a collaborative of states, they can address gaps in federal support and resources moving forward in key public health areas,” the person said. One of the areas they’re preparing to address is flagging federal support for vaccines, but the member states also have efforts underway to address pandemic preparedness, laboratory services, epidemiology and other key public health priorities.

One state represented in that group, Maine, has even recently struck language in its vaccine access law referencing ACIP and created a pathway to purchase vaccines outside of the federal Vaccines for Children Program, which provides vaccines for free to children whose families can’t afford them, and which public health advocates fear may also be under threat.

The new West Coast Health Alliance said that in the coming weeks it will finalize shared principles “to strengthen public confidence in vaccines and public health.” The group said they will also rely on guidance from national medical associations like the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists, which recently released guidance that broke from CDC’s around Covid-19 vaccines.

“In a vacuum of clear, evidence-based vaccine guidance, manufacturers lack reliable information to plan production, health care providers struggle to provide consistent plans of care, and families face uncertainty about access and coverage,” the West Coast Health Alliance statement reads.

“To protect the health of our communities, the West Coast Health Alliance will continue to ensure that our public health strategies are based on best available science.”

In a statement to CNN, Andrew Nixon, Director of Communications for HHS, said the states moves away from CDC guidance were based on partisanship, rather than science.

“Democrat-run states that pushed unscientific school lockdowns, toddler mask mandates, and draconian vaccine passports during the COVID era completely eroded the American people’s trust in public health agencies,” Nixon said. “ACIP remains the scientific body guiding immunization recommendations in this country, and HHS will ensure policy is based on rigorous evidence and Gold Standard Science, not the failed politics of the pandemic.”