FDA Investigates Multiple Reports of Adverse Reactions to Pfizer’s Vaccine

The FDA has announced that it is investigating multiple reports of allergic reactions to Pfizer/BioNTech’s COVID-19 vaccine as supplies of the shot continue to roll out across the U.S. this week.

According to the Centers for Disease Control and Prevention, six cases of anaphylaxis occurred in patients vaccinated with Pfizer’s vaccine, BNT162b2, but were caught in time and immediately treated. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said late Friday that the culprit could be polyethylene glycol, an ingredient in both the Pfizer and Moderna vaccines.

“We’ll be looking at all the data we can from each of these reactions to sort out exactly what happened, and we’ll also be looking to try to understand which component of the vaccine might be helping to produce them,” Marks said.

Pfizer has spoken out against U.S. government claims that it faces manufacturing delays for its COVID-19 vaccine, denying that it is seeing any problems in production or distribution of its shots and asserting it’s still on track to make more than 1 billion doses in 2021.

The company was responding in part to comments made by HHS Secretary Alex Azar during an Operation Warp Speed briefing last week. The HHS chief claimed that Pfizer had recently informed the federal government about “various challenges that they might have” in vaccine manufacturing, though he did not offer details, only vowing to provide the company “full support” for production operations.

Pfizer CEO Albert Bourla acknowledged last week that some vaccine components for an additional 100 million U.S. doses — which the drugmaker is still working out with the government and has not yet signed an official agreement for — could face “critical supply limitations” in the future. The executive stressed that he believes the related manufacturers will sort it out and “there will be no problem,” though he expressed support for President Trump invoking the Defense Production Act, if necessary, to compel suppliers to produce the needed components.

“We are asking [suppliers] right now for things. They haven’t done it yet, but we are asking them, and I hope they will do it very soon, because particularly in some components, we are running at critical supply limitations, but I think they will do it,” he said.

Bourla said Pfizer offered to provide an additional 100 million doses to the U.S. in the third quarter of 2021, but the U.S. is asking for them in the second quarter. Pfizer is working to allocate at least a large amount of the doses by the federal government’s requested timeline, he said.

A Pfizer spokesperson told FDAnews the drugmaker “is laser-focused on delivering the 100 million doses,” adding that the company “is confident in the ability of the U.S. government to remove any obstacle that may present itself as we work to ramp up manufacturing to deliver any additional doses.”

The drugmaker, the first to receive the FDA’s Emergency Use Authorization (EUA) for a coronavirus vaccine, emphasized in a statement that it has a hefty supply of doses of its vaccine stored away that are awaiting a greenlight for distribution.

“Pfizer is not having any production issues with our COVID-19 vaccine, and no shipments containing the vaccine are on hold or delayed. We successfully shipped all 2.9 million doses that we were asked to ship by the U.S. government to the locations specified by them,” the company said. “We have millions more doses sitting in our warehouse but, as of now, we have not received any shipment instructions for additional doses.”

Pfizer said that it believes it can deliver up to 50 million doses globally by the end of the year and up to 1.3 billion doses in 2021.

Responding to FDAnews’ inquiry about the warehouse doses still awaiting distribution, an HHS spokesperson said that “there was some confusion between planning and training numbers provided in mid-November and actual official weekly allocations, which are only available the week prior to distribution shipping because they are based on the number of releasable vaccine doses available.”

“We are working on clearing up any misunderstanding with the governors and jurisdictions,” the spokesperson said, noting that only two official Pfizer vaccine allocations have so far been provided to states, with the second allocation given on Dec. 15.

Operation Warp Speed’s chief operating officer, Gen. Gustave Perna, said Saturday that he takes sole responsibility for the confusion, an unusual admission of culpability from a government official. — James Miessler