The Centers for Disease Control and Prevention (CDC) reported that a preliminary analysis of the agency’s own vaccine database indicated that individuals aged 65 and older may be at a higher risk of experiencing an ischemic stroke 21 days after receiving the Pfizer/BioNTech bivalent injection.
An ischemic stroke, also known as cerebral ischemia, is caused by blockages in the arteries that carry blood to the brain.
The Food and Drug Administration (FDA) launched an extensive review of federal data after CDC investigators detected this potential stroke risk in the elderly.
The FDA reviewed data from 4.25 million seniors who received the Pfizer booster and found no increased risk of stroke.
The Department of Veterans Affairs also conducted a preliminary review of its database and did not identify an increased risk of stroke.
“So far, the data we have seen suggest no safety risk for bivalent boosters in those aged 65 and older,” said Richard Forshee, deputy director of the FDA’s Office of Biostatistics.
The FDA and CDC stated that other large studies in databases from other countries and in Pfizer-BioNTech databases did not signal this issue, adding that further investigation is needed.
Pfizer and BioNTech stated in a statement that they were informed of limited reports of ischemic strokes in individuals aged 65 and older following vaccination with the updated vaccine.
“Neither Pfizer nor BioNTech, nor the CDC or FDA, have observed similar findings in several other monitoring systems in the U.S. and worldwide, and there is no evidence to conclude that ischemic stroke is associated with the use of COVID-19 vaccines,” the companies said in a statement.
CDC investigators found that among the approximately 550,000 vaccine recipients recorded in the VSD database, 130 seniors experienced strokes within 21 days of receiving the Pfizer booster. A 70-year-old man died a month after the stroke, which was likely his cause of death, according to presented data.
The investigators conducted a small analysis indicating that seniors who received the Pfizer omicron booster and flu vaccine on the same day may have a higher risk of stroke, although the data is preliminary.
Although the FDA did not identify a stroke risk, the agency is launching a study to examine potential safety concerns that may arise from administering the Covid omicron vaccines alongside flu vaccines, Forshee said. The study will help the agency prepare for the vaccination campaign in the 2023-2024 respiratory virus season, he said.
This concern regarding a possible vaccine side effect was not identified with the bivalent injection from Moderna (MRNA.O).
Both the CDC and FDA continue to recommend that everyone aged 6 months and older stay up to date with their Covid 19 vaccinations.
Source: Reuters and CNBC