BOSTON (CBS) — Multiple Boston hospital networks including Mass General Brigham, Beth Israel Lahey Health and Wellforce announced Thursday that there will be a future COVID vaccine requirement for their workers.

I-Team sources tell WBZ-TV that Mass General Brigham will require its employees to be vaccinated against the coronavirus once a vaccine receives full FDA approval. Beth Israel Lahey Health and Wellforce, which includes Tufts Medical Center, Lowell General Hospital and MelroseWakefield Healthcare, announced similar requirements.

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Pfizer and Moderna have both requested full FDA approval, but that process will take months.

The FDA has granted emergency use authorization to the Pfizer, Moderna and Johnson & Johnson vaccines.

“Based on the research, data and trends, we have made the decision that all Mass General Brigham employees will be vaccinated against COVID-19 once the FDA has granted approval of one of the three vaccines,” Mass General Brigham CEO Dr. Annie Kilbanski said in a letter to staff. “This step to require the COVID-19 vaccine as a condition of employment is consistent with our approach to the flu vaccine requirement implemented in 2018.”

Kilbanski said that employees will be able to request an exemption for religious or medical reasons, as will workers who are pregnant or intend to become pregnant.

More than 85% of Mass General Brigham employees are already vaccinated against COVID.

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Beth Israel CEO Dr. Kevin Tabb said all staff will be required to get vaccinated against the flu and COVID once the vaccines are fully licensed by the FDA.

“After the EUA is lifted, it will be a requirement that all staff be vaccinated against COVID as a condition of employment,” he said.

Wellforce said in a statement that the FDA is expected to approve the vaccines later this year.

“Our number one priority is the health and safety of our patients, employees, and clinicians,” Wellforce said. “That is why today we are announcing that we will require those who work within our hospitals and health system to be vaccinated against COVID-19 following the full FDA approval of one of the current vaccines.”

For now, Boston Medical Center is holding off on a vaccine requirement.

“Boston Medical Center firmly believes in the science and efficacy of the vaccine and its ability to protect our staff, patients and our communities from COVID-19,” a hospital spokesman said. “We are reviewing our policy regarding COVID vaccinations for employees. While COVID vaccinations are currently voluntary, BMC is actively encouraging and talking with our employees and our patients and their families about the benefits of getting vaccinated.”

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Vaccine mandates have proved controversial at health care employers elsewhere in the country. Earlier this week more than 150 workers at a Houston hospital system were fired or resigned over the requirement.

CBSBoston.com Staff