Three unions representing 2 million healthcare workers are saying that their members will refuse to receive or administer a COVID-19 vaccine without validation from independent third-party experts.

The Service Employees International Union, American Federal of Teachers and the American Federation of State, County and Municipal Employees said in a joint statement Tuesday that they are “deeply troubled by the evident politicization” of the vaccine process.

“We need a transparent, evidence-based federal vaccine strategy based on principles of equity, safety and priority, as well as robust efforts to address a high degree of skepticism about safety of an authorized vaccine,” the statement reads. “We know that we need a safe, effective vaccine to end this pandemic. When one is available that is clearly proven to be both, we are ready to both take the vaccine and to administer it.”

The organizations said that they understand the “devastating impact of SARS-CoV-2,” have witnessed deaths from the virus, have lost coworkers and friends, and “continue to work every day to support patients who are gravely ill.” 

But they said that reports of presidential appointees directly interfering in Centers for Disease Control and Prevention guidance point to “corrupting a process which should be based solely on science.” 

“While pharmaceutical companies have signed a statement of principles on safety and efficacy, they are also competing for billions of dollars in government contracts,” the statement reads. “Given this record of politicization of public health, it is impossible for us to take or promote any vaccine without additional assurance for independent experts that the approval process has not been tainted.”

The three organizations said once a vaccine is identified, they will work with federal, state and local bodies, and with the leadership of the healthcare community and the communities they serve, to educate the public and “promote a fair and effective vaccination program for distributing this desperately needed vaccine.”