Wall Street Times

Pfizer unlikely to raise stroke risk for seniors getting booster shot

Pfizer: People continue to resist vaccinations despite the need for Covid-19 booster doses and immunizations in general because they are afraid of becoming sick.

Seniors, in particular, are concerned about the potential side effects of the injections since many have grown anxious about the prospect of having a stroke.

The Centers for Disease Control and Prevention, however, has conducted studies to allay such worries.


People who had the Pfizer booster dose for the omicron Covid variant were speculated to have an increased risk of stroke if they were 65 years of age or older, prompting a surveillance system used by the CDC.

An integrated healthcare organization, networks across the US, and the CDC’s Immunization Safety offices worked together to create the Vaccine Safety Datalink (VSD) system.

It monitors and evaluates the safety of immunizations using electronic health data from cooperating sites.

It provides information on the kind administered, the date of immunization, and any other vaccines received on the same day.

The VSD also uses information on medical conditions identified during doctor’s office visits, urgent care visits, ER visits, and hospital stays.


The CDC posted a statement on its website on Friday.

Following the availability and use of the updated (bivalent) COVID-19 vaccines, CDC’s Vaccine Safety Datalink (VSD), a near real-time surveillance system, met the statistical criteria to prompt additional investigation into whether there was a safety concern for ischemic stroke in people ages 65 and older who received the Pfizer-BioNTech COVID-19 Vaccine, Bivalent.

Rapid-response investigation of the signal in the VSD raised a question of whether people 65 and older who have received the Pfizer-BioNTech COVID-19 Vaccine, Vivalent were more likely to have an ischemic stroke in the 21 days following vaccination compared with days 22-42 following the vaccination.

The Centers for Medicare and Medicaid Services database analysis of the updated immunizations revealed no increased risk of stroke.

Additionally, the updated vaccinations have not shown any signs of stroke in Pfizer-BioNTech’s global safety database.

Read also: Drinking: steps to leaving it behind in 2023


A CDC spokeswoman said that the problem was brought up for the first time in late November.

The CDC began looking into the possibility of seniors getting a stroke 21 days after receiving the Pfizer injection when it was discovered in the middle of December, and worries persisted.

The initial signal and outcomes were the same for Moderna boosters.

The Pfizer omicron booster shot, according to the spokesman, caused strokes in 130 persons aged 65 and older within 21 days.

Over 550,000 seniors who had their booster injection provided the data.

According to the CDC, no other surveillance system has so far discovered any issues with the Pfizer booster.


Investigators examined data from the following sources and found no extra risk of stroke associated with the Pfizer booster:

  • Center for Medicare and Medicaid Services
  • The Department of Veterans Affairs
  • The Vaccine Adverse Reporting System
  • Pfizer’s global safety database

“Although the totality of the data currently suggests that it is very unlikely that the signal in VSD represents a true clinical risk, we believe it is important to share this information with the public, as we have in the past, when one of our safety monitoring systems detects a signal,” the CDC wrote.

The monitoring devices, according to the CDC, pick up signals from variables unrelated to the immunization.

The agency spokesperson also stated that additional information and a clearer picture are expected from the investigations in the upcoming weeks.


On January 26, the Food and Drug Administration will convene a panel discussion with independent vaccination specialists to address the inquiry.

On Friday, Pfizer also published a statement stating there’s no proof that ischemic stroke is connected to the company’s Covid vaccination.

Pfizer, BioNTech, the CDC, and the FDA have not discovered any links in different monitoring systems in the United States, according to company spokesman Kit Longley.

“Compared to published incidence rates of ischemic stroke in this older population, the companies to date have observed a lower number of reported ischemic strokes following the vaccination with the omicron BA.4/BA.5-adapted bivalent vaccine,” said Longley.

The CDC continues to advise the Pfizer omicron injection.

Those who have finished the primary immunization series and are five years of age or older are eligible for the booster.

The youngest children eligible for the omicron injection range from under six months to four years old.


CDC says it’s ‘very unlikely’ Pfizer booster carries stroke risk for seniors after launching review

CDC & FDA identify preliminary COVID-19 vaccine safety signal for persons aged 65 years and older