Monitoring Desk
ISLAMABAD/WASHINGTON: An upgraded Pfizer/BioNTech Covid-19 booster shot may increase the risk of stroke in older persons, according to recent findings from one CDC database in the US. Still, the signal is weaker than what the agency had flagged earlier in January, health officials said on Thursday.
US Food and Drug Administration authorities claimed they had not found evidence of a connection between strokes and injections in two safety monitoring databases. The new evidence was discussed at a conference of outside specialists advising the FDA on vaccine policy.
US health officials announced earlier this month that their vaccine safety datalink (VSD) database had revealed a potential connection between older adults who received the more recent booster shots and ischemic strokes. They said it was very unlikely to represent an actual clinical risk at the time.
Dr. Nicola Klein of healthcare company Kaiser Permanente, which maintains VSD data for the CDC, said the stroke rate in the database had slowed in recent weeks. However, the signal was still statistically significant, likely not by chance.
Agency plans to study the increased risk of stroke from receiving two Pfizer shots simultaneously
She said that most of the confirmed cases had also received a flu vaccine simultaneously, which might be a factor. Richard Forshee, the FDA scientist, said the agency plans to study whether there is any increased risk of stroke from receiving the two shots of Pfizersimultaneously.
Both agencies still recommend that older adults receive the booster shots, now tailored to target Omicron variants and the original coronavirus.
Professor of medicine at the University of Pittsburgh, Dr. Walid Gellad, said the issue needs further investigation. Gellad wrote in an email that “signals are not always clear.” Further investigation is warranted, given the proven benefits of receiving the booster in this age group, but changing current practice is not justified.
