Stroke After Pfizer Booster May Be Connected to Flu Vaccine: Officials

Instances stroke After receipt Pfizer’s new booster in the elderly may be connected to the influenza vaccine, officials said on Jan. 26.

One-hundred thirty cases of ischemic stroke, which can be deadly, were recorded among people aged 65 or older within 21 days of a bivalent Pfizer booster, the U.S. Food and Drug Administration’s Vaccines and Related Biological Products Advisory Committee heard on Thursday.

This was more than the 92 cases that were recorded within the 22-to-42-day period following vaccination. Thus, the safety signal was activated.

The U.S. Centers for Disease Control and Prevention and the administration (FDA). revealed the signal on Jan. 13 but had not said how many cases were recorded from the U.S. government’s Vaccine Safety Datalink surveillance system, which contains records from 12.5 million people across 11 sites.

An initial review of medical records from one location, which had 24 cases of stroke in the three weeks after Pfizer vaccinations, showed that the majority of stroke victims had received an influenza vaccine on the same day as the COVID-19 vaccine.

None of the patients had suffered from strokes or transient ischemic attacks in the past. This is similar to a stroke but could also be due to non-vaccine causes of ischemic stroke.

Three patients, including one man, died after the stroke. His death was attributed to the health problem.

There were 40 cases of strokes in people who had suffered strokes between Dec. 17 and 17, 2022. Post-signal analyses raised the safety signal which means that vaccines may cause an illness. Based on background rates, 34.5 cases were predicted.

60 cases were reported among the elderly who had received a bivalent COVID-19 vaccination but not a flu vaccine. The signal was not met by this number.

Officials decided to examine the first analysis by comparing the cases of boosted individuals one to 21 days after vaccination to those of boosted persons 22 to 42 days later. It was argued that vaccine-received people were more likely to have a higher chance of developing a disease. “expected to be more similar to current vaccinees than unvaccinated individuals.”

Officials also stated that post-vaccination cases of ischemic stroke were excluded if the person has a personal history with certain conditions such as transient ischemic attack and atrial fibrillation (also known as irregular heartbeat).

The updated information was sourced from a set of slides that Dr. Tom Shimabukuro, a CDC official, and Dr. Nicola Klein, a Kaiser Permanente official who works closely with the CDC, presented to the FDA’s vaccine advisory panel.

“CDC and FDA are engaged in epidemiologic analyses regarding coadministration of COVID-19 mRNA bivalent booster and flu vaccine,” One slide was shown following the detection. “significant cluster” Ischemic stroke cases after vaccination.

The CDC and FDA said previously that an examination of other surveillance systems showed no signal of ischemic stroke for the bivalent boosters but failed to mention that an analysis of reports to the Vaccine Adverse Event Reporting System, which the agencies co-manage, for the original Pfizer and Moderna COVID-19 vaccines triggered the signal For ischemic stroke and many other adverse effects. The original vaccines are still available in the United States. Bivalents are only available as boosters.

In a joint statement, Pfizer and BioNTech stated that they were made aware by the partners. “limited reports of ischemic stroke” Observed in Vaccine Safety DataLink.

“Neither Pfizer and BioNTech nor the CDC or the U.S. Food and Drug Administration (FDA) have observed similar findings across numerous other monitoring systems in the U.S. and globally and there is no evidence to conclude that ischemic stroke is associated with the use of the companies’ COVID-19 vaccines,” These companies were identified.

Israel and the European Union have said Bivalent vaccination has not been linked to ischemic stroke, according to the officials. European officials said they also looked at Pfizer’s original vaccine.

In 2022, Signal First Identified

These slides also revealed that the safety signal from Vaccine Safety Datalink was first identified on the slide in 2022.

Nov. 27, 2022 was the first time that the condition received the signal. One slide was visible. The signal continued to be received by the condition until Jan. 8, 2023.

The signal was received “persistent for 7 weeks,” One slide was used.

While the rate ratio (or the outcome of the analyses) “has slowly attenuated from 1.92 to 1.47,” It “has continued to meet signaling criteria,” The slides were acknowledged.

The CDC did in fact not respond immediately to a request.

Klein indicated during the meeting that the rate has dropped so much that it is no longer matching the signal.

Officials stated that they will continue to monitor data from datalink, expand the record review to all site sites and examine data from other systems in order to better understand the role of flu vaccination with COVID-19 vaccine, as well as the indications of a lower rate of stroke within the first three to six weeks after vaccination.