SACRAMENTO — With the U.S. Centers for Disease Control and Prevention in turmoil as vaccine skeptics gain influence in the Trump administration, California is partnering with Washington and Oregon to form a pact that will offer its own public health recommendations.

Govs. Gavin Newsom of California, Tina Kotek of Oregon and Bob Ferguson of Washington announced Wednesday the creation of the West Coast Health Alliance, which they said will provide science-based recommendations at a time when the nation’s top public health agency is reversing long-standing vaccine guidance.

Robert F. Kennedy Jr. , the secretary of the U.S. Department of Health and Human Services and a loyal Trump ally, has dismissed top scientific advisors and fired top leadership at the CDC, moves that have shaken public confidence in its direction. And Kennedy has warned that more turnover could be coming.

“President Trump’s mass firing of CDC doctors and scientists — and his blatant politicization of the agency — is a direct assault on the health and safety of the American people,” the three governors said in a joint statement Wednesday. “The CDC has become a political tool that increasingly peddles ideology instead of science, ideology that will lead to severe health consequences.”

The rebuke from the West Coast states reveals the escalating concerns about the life-and-death consequences of the Trump administration’s healthcare agenda. For decades, the CDC has been the nation’s trusted authority on vaccines — setting childhood immunization schedules, guiding which shots adults should receive and shaping state health policies across the country.

The states said the focus of their health alliance will be on providing evidence-based recommendations about who should receive immunizations while ensuring the public has access to credible information about the safety and efficacy of vaccines.

It’s not the first time the three states have partnered to counter upheaval within the federal public health agency. In June, the states condemned Kennedy’s decision to remove all 17 members of the CDC’s Advisory Committee on Immunization Practices. Among the replacements named by Kennedy are appointees who spread vaccine misinformation and relayed conspiracy theories during the COVID-19 pandemic, according to the Associated Press.

Kennedy said the change would improve public trust by ensuring members of the committee didn’t have “any specific pro- or anti-vaccine agenda.”

Polling suggests the opposite effect. A Kaiser Family Foundation poll last month found Americans across the political spectrum are increasingly uncertain about public health guidance and whether new recommendations from the administration will make them more or less safe.

Experts say that not only are vaccines crucial for the health of individuals and the community but they also ultimately save money — preventing sickness and the rise in healthcare costs that would accompany widespread disease outbreaks.

Andrew Nixon, director of communications at Health and Human Services, told The Times that it was in fact California and Washington that had undermined trust in public health with their response to the coronavirus pandemic, and he pushed back against attempts to create a shadow CDC.

“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,” he said.

Nixon said the CDC’s vaccine advisory committee “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.”

The clash over vaccine guidance comes as a new wave of COVID takes hold and flu season nears. In California, some county-level health officials are recommending that residents take greater precautions, such as temporarily wearing masks in indoor public settings. The CDC estimates that as of last week, COVID infections were growing or probably growing in 30 states and the District of Columbia.

The increase comes as federal guidance is making it more difficult for people to receive the COVID vaccine. The Food and Drug Administration, which falls under Kennedy’s purview, now requires adults 65 and younger and otherwise healthy — who say they don’t have an underlying health issue — to consult with a healthcare provider before getting the shot. Similarly, the CDC requires parents of healthy children to talk to a healthcare provider before their child can receive the COVID vaccine, a barrier the American Academy of Pediatrics called “deeply troubling.”

The American Academy of Pediatrics issued its own COVID vaccine guidance, countering what the CDC recommended, that says all young children 6 months to 23 months should be vaccinated, as well as certain high-risk older children. The group has also said that older children should be offered the vaccine if their parents request it.

Earlier this year, the CDC changed its vaccine schedule from recommending the COVID vaccine to all pregnant women to offering “no guidance” as to whether healthy pregnant women should get the vaccine. In response, the American College of Obstetricians and Gynecologists recommended that people receive the updated COVID-19 vaccine at any point during their pregnancy.

It’s not the first time California has created a state safeguard to vet federal vaccine recommendations. In 2020, Newsom created a group of physicians and scientists working at the California Department of Public Health to independently review all newly created FDA-approved COVID vaccines, which were developed during President Trump’s first term in office. The concern at the time was that the White House would rush the approvals under an initiative dubbed Operation Warp Speed.

Three other states — Washington, Oregon and Nevada — quickly joined California’s initiative, which was renamed the Western States Scientific Safety Review Workgroup and reviewed subsequent versions of the COVID vaccines. The review group returned saying the vaccines were safe and effective.

Now, amid mounting turmoil at the CDC, California is reviving that playbook, saying the public needs credible information about the safety and efficacy of vaccines. The three-state effort follows more than 1,000 current and former U.S. Health and Human Services officials calling on Kennedy to resign.

Kennedy is expected to face a bipartisan grilling from the Senate Finance Committee on Thursday morning, where he had already been scheduled to testify on the president’s healthcare agenda for the coming year. Sen. Bill Cassidy, a Republican from Louisiana and a member of the committee, has vowed “oversight” over Kennedy and the agency after expressing concern over his skeptical approach to vaccine policy.

Peter Chin-Hong, an infectious disease expert at UC San Francisco, said that although California’s health alliance with Oregon and Washington is, for now, largely symbolic — providing an alternative voice to the CDC — it does risk adding to the polarization of healthcare. It’s paramount, he said, that healthcare practitioners from across the political spectrum come together.

Chin-Hong said other state alliances are also forming, including eight states in the Northeast and a group of healthcare systems in the upper Midwest.

“What you are seeing is people standing up for science — coming together and bringing people together to give a counter argument to what the CDC is saying,” Chin-Hong said.

But things may become more difficult when it comes to funding vaccination programs. He said insurance companies typically follow CDC guidance. If the federal government is not recommending vaccines, it’s unclear how they’ll be covered.

Still, Chin-Hong noted the challenges of political division and community resistance surrounding immunizations, pointing to Florida’s announcement that vaccines will no longer be mandated in public schools.

“It’s all so bananas,” he said. “It’s like today is ‘opposite day’ and we’re all in some Dr. Seuss story where nothing is what it seems.”

Jake Scott, an infectious disease physician and clinical associate professor at Stanford School of Medicine, said the alliance could put the three states at risk of retaliation by Trump and his allies.

“We’ve already seen how this administration uses federal agencies to go after states that won’t fall in line,” Scott said. “These states are likely looking at reduced federal funding, regulatory harassment, you name it. But honestly, what’s the alternative? The cost of just letting preventable diseases spread, of completely losing public trust in vaccines, of throwing out decades of medical evidence — that would be catastrophic. From a medical perspective, these states really don’t have a choice here, regardless of the political fallout.”

Times staff writer Rong-Gong Lin contributed to this report.

NEW YORK — Amanda Anisimova upset Iga Swiatek 6-4, 6-3 in the US Open quarterfinals Wednesday, less than two months after losing to the six-time Grand Slam champion in the Wimbledon final by a 6-0, 6-0 score.

The No. 8-seeded Anisimova reached her third major semifinal and first at Flushing Meadows.

“To come back from Wimbledon like that is really special to me,” said Anisimova, who was born in New Jersey and grew up in Florida. “I feel like I worked so hard to try and turn around from that. … Today is really special.”

The powerful strokes and poise she displayed in Arthur Ashe Stadium against No. 2 Swiatek — the 2022 US Open champion — were such a striking contrast to what happened at the All England Club’s Centre Court on July 12.

That title match lasted just 57 minutes, and Anisimova only managed to win 24 points that day, a total she eclipsed about midway through the first set this time. Anisimova cried during her runner-up speech during the trophy ceremony at Wimbledon; on Wednesday, she was all smiles while addressing thousands of supportive spectators who kept interrupting her on-court interview with cheers.

“Playing here is so freaking special,” Anisimova said, “and I’ve been having the run of my life here.”

On Thursday, Anisimova will try to reach a second consecutive major final. She’ll face four-time Grand Slam champion Naomi Osaka — who eliminated Coco Gauff on Monday — or Karolina Muchova in the semifinals.

After one game against Swiatek in the quarterfinals Wednesday, Anisimova might have been forgiven for thinking, “Oh, no. Not this again.”

That’s because Anisimova served first and got broken immediately when she lost three points in a row by missing forehands — one into the net, one wide, one long.

But Anisimova broke right back and soon was the one dictating points with her strong, flat groundstrokes that wound up contributing to 23 total winners, 10 more than Swiatek accumulated. Anisimova also played quite cleanly, making just 12 unforced errors.

In the second set, Anisimova fell behind again, this time 2-0. But she again regrouped and quickly gained the upper hand. Swiatek was the one looking increasingly frustrated, shaking her head or slumping her shoulders between points, spreading her arms wide and looking to her coach for advice, and leaning back in her changeover chair as if pondering what, exactly, she could do differently.

When Swiatek double-faulted to trail 5-3 in the second set, that allowed Anisimova to serve out the victory.

“From the get-go, I was trying to fire myself up,” Anisimova said. “She is one of the toughest players I’ve ever played. I knew I was going to have to dig deep.”

After taking down world No. 1 Aryna Sabalenka in the Wimbledon semifinals, Anisimova is the first American woman to defeat a WTA Top-2 player in back-to-back majors since Serena Williams in 2012 at Wimbledon and the US Open.

Having just turned 24 on Sunday, Anisimova is also the youngest woman to reach a major semifinal on all three surfaces since 23-year-old Simona Halep at the 2015 US Open.

ESPN Research and The Associated Press contributed to this report.