No increased stroke risk linked to Pfizer’s Covid booster, federal officials say

Concerns that Covid booster shots made by Pfizer BioNTech could increase the risk of stroke in people over the age of 65 were not supported by intensive scientific research, federal officials said Friday. .

Officials said it was “extremely unlikely” the risk was real. They urged Americans six months and older to continue booster shots. Decided to disclose the results of the investigation.

“We believe it is important to make this information available to the public.” Joint statement According to the Centers for Disease Control and Prevention and the Food and Drug Administration,

Officials declined requests to discuss the details of the investigation.

This bivalent vaccine is designed to stop the original version of the coronavirus and a variant of Omicron that swept the United States over the summer. His bivalent vaccine, manufactured by Pfizer-BioNTech and Moderna, is the only booster currently available in the United States, scientists say have heated debates For usefulness compared to the original vaccine.

It is unclear whether the new sense of security will encourage Americans to get bivalent injections if they haven’t already. Is not … received so far Bivalent booster shot.

Concerns about a possible link to ischemic stroke, which can interfere with the blood supply to the brain, first surfaced late last year. Data from Vaccine Safety Datalink, a federal safety monitoring system, shows that Americans 65 and older may have an increased risk of ischemic stroke 21 days after receiving her bivalent vaccine from Pfizer and Biontech. suggests that

The signal was specific to a bivalent vaccine manufactured by Pfizer Biotech. Similar concerns were not related to his original Covid vaccine or Moderna’s bivalent booster.

The data prompted federal authorities to scrutinize other vaccine safety databases and observations from the United States and other countries. Investigators found no evidence of an increased risk of stroke in any of these sources, federal officials said in a statement.

Federal officials plan to discuss the findings at the FDA’s Scientific Advisory Meeting on Future Covid Vaccines on Jan. 26.

of Vaccine safety data link A real-time monitoring system, a collaboration between the CDC and integrated medical institutions and national networks. The system uses electronic health data from about 10 sites across the country to monitor vaccine safety.

Of the approximately 550,000 people aged 65 and older who received the Pfizer-BioNTech bivalent booster, 130 had an ischemic stroke within 21 days of receiving the injection, raising concern that the two events were linked. I was. However, analysis of the data using alternative methods did not reveal an increased risk of ischemic stroke.

Another database maintained by the CDC and FDA, the Vaccine Adverse Event Reporting System, also detected no signal for ischemic stroke. So did a large bivalent vaccine study based on data from the Centers for Medicare and Medicaid Services, a preliminary study using the Veterans Affairs database, or the Pfizer-BioNTech global safety database.

No other country has observed an increased risk of ischemic stroke with bivalent vaccines, officials said.About 795,000 strokes reported annually in the United StatesAbout 87% of them are ischemic strokes, according to the CDC.

“There is no evidence to conclude that ischemic stroke is associated with corporate Covid-19 vaccine use,” Pfizer and BioNTech said in a statement. More than one bivalent vaccine was administered.

“Compared to the published incidence of ischemic stroke in this elderly population, companies have observed a low number of reported ischemic strokes to date.” After bivalent injectionthe company said.