Originally Published: 21 JUL 23 15:11 ET

Updated: 21 JUL 23 16:45 ET

By Meg Tirrell, Kevin Conlon and Brenda Goodman, CNN

(CNN) — Most of the damage from Wednesday’s tornado to a major Pfizer plant in North Carolina was to a warehouse facility, rather than areas that produce medicines, the drug giant said Friday.

The plant remains closed while damage is assessed, and Pfizer Chief Executive Officer Albert Bourla said in remarks at the site that it would be weeks, not days, until it’s back online, although he said he couldn’t speculate on a precise time frame.

“We are dealing with a big disaster in terms of damages,” Bourla said in a press conference Friday. “We have a monumental task in front of us.”

Pfizer said it’s “committed to rapidly restoring full function to the site, which plays a critical role in the US healthcare system,” and noted it’s working with US Food and Drug Administration Commissioner Dr. Robert Califf, North Carolina Gov. Roy Cooper and other state, local and federal officials on the effort.

The company said it supplies about 8% of all sterile injectable medicines used in US hospitals, and this plant, in Rocky Mount, accounts for a quarter of that. A previous fact-sheet had suggested that the Rocky Mount plant itself was responsible for more than 25% of all sterile injectables used in US hospitals.

Drug shortages experts are worried the natural disaster may exacerbate an already historic crisis in access to medicines in the US.

Bourla said Friday that the company’s top priority is minimizing supply disruptions, and pledged that “no American will feel the lack of medicines” in hospitals.

Pfizer didn’t provide a detailed list of products made at the plant, but US Pharmacopeia, a nonprofit organization, said its Medicine Supply Map identified more than 150 medications made at the facility, about half of which are on the FDA essential medicines list. It said its review shows that many of the products made at the plant have been in shortage recently and were already at risk of falling into shortage before the tornado.

USP said products made there include electrolytes like potassium chloride and magnesium sulfate, which are used for conditions including severe dehydration, cardiac arrest and metabolic acidosis; and anesthetics and analgesics, used in hospitals to control pain, including controlled substances like morphine and fentanyl, which can be used for pain management for cancer patients or in acute care.

The fact that the warehouse sustained the bulk of the damage rather than production lines, manufacturing experts had suggested, could mean any potential shortages wouldn’t last as long as if drug manufacturing were taken down.

The company said the warehouse facility stores raw materials, packaging supplies and finished medicines waiting to receive quality assurance. Bourla said that crews are on site working to restore power and to assess the structural integrity of the buildings.

Pfizer said it’s working to move products to other nearby sites for storage and to find ways to replace damaged raw materials and supplies, and is looking at alternative manufacturing locations in the US and internationally, both through its own sites and through partners. Bourla said that facilities under consideration include one in Sanford, North Carolina.

Bourla noted that employees at the Rocky Mount site, where 3,200 Pfizer employees and contractors work, were able to evacuate safely and reach storm shelters before the tornado hit Wednesday. He didn’t say how long the plant would be closed, but said all workers would be paid through the duration. Pfizer also said it would donate to the American Red Cross North Carolina Chapter and United Way Tar River Region to help support the community as it rebuilds.