One week after the FDA and CDC found a potential safety concern linking ischemic stroke in older adults to the updated Pfizer vaccine, Israel and EU drug regulators announced they had not found a link between the two.
Ischemic strokes occur when blood clots or other particles block the blood vessels to the brain.
Reuters first reported on Thursday that an Israel health ministry official said there were no links found between the vaccine made by Pfizer and its German partner BioNTech, and strokes.
“We have not turned up such a finding, even after we went back and rechecked all our data after the FDA announcement,” Salman Zarka, the head of Israel’s coronavirus task force, said in a video briefing sent to Reuters last week.
On Jan. 18, the European Medicines Agency also told Reuters that it hasn’t found a safety concern in the EU with the vaccine but that it would continue to monitor data.
In a statement jointly posted by the FDA and CDC regarding the safety signal, the agency noted that only one of its multiple safety systems, Vaccine Safety Datalink, found a potential problem:
Rapid-response investigation of the signal in the VSD raised a question of whether people 65 and older who have received the Pfizer-BioNTech COVID-19 Vaccine, Bivalent were more likely to have an ischemic stroke in the 21 days following vaccination compared with days 22-44 following vaccination.
Followup analyses of the data also did not find a safety signal in Pfizer-BioNTech’s vaccine, and no issues were detected with Moderna’s shot, according to the FDA. The followup analyses included other large vaccine datasets from Medicare, the United States Department of Veterans Affairs, Pfizer’s and BioNTech’s own monitoring programs and a vaccine side-effect reporting collection tool known as VAERS.
The FDA and CDC do not recommend any “change in vaccination practice.”
According to data collected by the CDC, 69% of the US population has completed the original vaccine series, and 16% — about 50 million people — have received the updated booster.
Any vaccine carries some level of risk or side effect, though typically far smaller than the consequences of diseases they are meant to guard against.
In an emailed statement to Endpoints News, Pfizer said “there is no evidence to conclude that ischemic stroke is associated with the use of the companies’ COVID-19 vaccines.
“Compared to published incidence rates of ischemic stroke in this older population, the companies to date have observed a lower number of reported ischemic strokes following the vaccination with the Omicron BA.4/BA.5-adapted bivalent vaccine,” the statement continued. “With hundreds of millions of doses of the original and Omicron BA.4/BA.5-adapted bivalent Pfizer-BioNTech COVID-19 vaccine administered globally, the benefit-risk profile of our vaccines remains positive for all authorized indications and age groups.”