Experts, Pfizer’s bivalent COVID-19 shot is “extremely unlikely” to raise seniors’ risk of stroke.
After Pfizer initiated an investigation into a preliminary safety issue identified by one of its monitoring systems, US federal health officials stated that it is “extremely improbable” that Pfizer’s bivalent COVID-19 injection increases the risk of stroke for adults 65 and older.
No other surveillance system has, to date, identified a similar safety concern, according to a statement released on Friday (Jan. 13) by the US Centre’s for Disease Control and Prevention (CDC).
The Centre’s for Medicare and Medicaid Services (CMS) database was used in a large trial of updated (bivalent) vaccines (from Pfizer-BioNTech and Moderna) that found no increased risk of ischemic stroke.
The new bivalent vaccines were mentioned, but it was added that further research is needed because other nations have not shown an increase in the risk of ischemic stroke with them.
The CDC continued, “Frequently, these safety systems pick up signals that might be caused by causes other than the vaccine itself.” The problem was discovered for the first time, according to The Washington Post, in late November.
A potential safety concern was discovered by the CDC’s vaccine safety datalink (VSD), a near real-time surveillance system. People 65 and older were more likely to experience an ischaemic stroke 21 days after receiving the Pfizer-BioNTech bivalent shot than they were from days 22 to 44 after receiving it.
Blockages in the arteries that supply blood to the brain are what cause an ischemic stroke, sometimes referred to as cerebral ischaemia.
“Further research is warranted because there might be additional confounding factors that contribute to the signal seen in the VSD. It’s also crucial to remember that no other safety systems have yet displayed a similar signal, and numerous subsequent assessments have failed to validate this signal “the CDC stated.
Although the sum of the data at this time indicates that it is highly improbable that the signal in VSD reflects a genuine clinical danger, we think it’s necessary to let the public know about this.
According to a joint statement from Pfizer and BioNTech, there have been a few isolated cases of ischemic strokes in adults 65 and older after receiving the revised vaccine.
There is no evidence to draw the conclusion that the use of the companies’ COVID-19 vaccines is related to ischaemic stroke, the companies added. “Neither Pfizer and BioNTech nor the CDC or FDA (Food and Drug Administration) have observed similar findings across numerous other monitoring systems in the US and globally.”
Moderna’s bivalent shot has not been linked to this safety issue. Everyone aged six months and older should continue to receive their COVID-19 immunization, according to recommendations from the CDC and FDA.