A preliminary link between Pfizer’s Covid vaccine and an increased stroke risk in seniors cannot be stood up in further datasets, Centers for Disease Control and Prevention (CDC) and Food and Drug Administration (FDA) have said.
On Friday the CDC and FDA announced one of the four main databases used to track Covid vaccine injuries had detected an association between the updated bivalent shot and ischemic strokes in over-65s.
The find came from the Vaccine Safety Datalink (VSD), a near real-time surveillance system monitoring the safety of vaccines containing health records of more than 12 million Americans. It found that 130 seniors had the stroke within 21 days of the shot — representing 0.02 percent of the roughly 550,000 seniors who received the shot.
The agencies said it was ‘very unlikely’ the signal represents ‘a true clinical risk’ because it was only a tiny proportion of the group and the finding was not stood up in four other large databases that had a much larger sample size.
The Vaccine Safety Datalink (VSD) found that 130 people ages 65 and older had a stroke within 21 days of receiving the Pfizer omicron booster among about 550,000 seniors. Subsequent CDC investigations using datasets from Medicaid, Veterans Affairs and the Vaccine Adverse Reporting System (VAERS) did not replicate the finding. VAERS – which anyone can report to – received over 1,082,000 reports between 2019 and 2022. Between December 14, 2020, and January 4, 2023, VAERS received 18,533 preliminary reports of death among people who received a Covid shot. By contrast, a report from the Commonwealth Fund estimated Covid vaccines have saved three million lives
The CDC and FDA cross-referenced other databases – including the Vaccine Adverse Reporting System (VAERS) – and failed to confirm the finding, suggesting it was a one-off.
And an FDA official told the Washington Post: ‘We have looked at the totality of the evidence, and there are no concerns at this time that this represents a true safety signal.’
A similar safety signal was not detected for Moderna’s booster in the VSD – despite the shot using the same mRNA technology as Pfizer – and no other age group appeared to be affected.
When health officials ran a different analysis of the VSD, they could not find the same signs for concern.
But they hope the CDC safety signal will not put people off getting the shot. After all, the Covid vaccinations have saved an estimated three million lives, The Commonwealth Fund estimated.
The issue was first detected in late November, a CDC spokesperson said, and an investigation was launched in mid-December.
The finding raised alarm bells as it suggested that people who received the bivalent were more likely to have an ischemic stroke in the 21 days post-vaccination compared to days 22-42 after the shot.
This ‘met the statistical criteria to prompt additional investigation’, the CDC statement said.
CDC officials used an alternative methodology to conduct a different analysis in the VSD database but could not replicate the finding.
They also checked the Center for Medicare and Medicaid Services system, containing 83.9 million individuals, and the Veterans Affairs database, with nine million people. Neither dataset indicated an increased risk of ischemic stroke following a bivalent vaccine.
The Vaccine Adverse Reporting System (VAERS) and Pfizer’s global safety database have also not seen more reports of ischemic strokes since people received the bivalent shots.
Anyone can report to the VAERS, co-managed by CDC and FDA, including patients, family members, healthcare providers and vaccine manufacturers.
Between 2019 and 2022, the VAERS received over 1,082,000 reports.
It is unclear how many people are in Pfizer-BioNTech’s global safety database, but 46,331 people took part in its landmark trial in 2020.
Furthermore, other countries have not seen any indication that the bivalent booster leads to an increased risk for ischemic stroke.
More than 396 million Pfizer-BioNTech Covid-19 vaccine doses have been administered in the US as of January 4, 2023, according to Statista.
And more than 4.3 billion Pfizer doses have been shipped worldwide, as of December 11, 2022.
Covid vaccines have saved three million lives in America, according to a report by The Commonwealth Fund, with more than 665 million doses being administered between December 14, 2020, and January 4, 2023.
During that time, VAERS received 18,533 preliminary reports of death (0.0028 percent) among people who received a Covid shot. These deaths were not necessarily directly caused by the vaccine.
Continued monitoring has so far identified nine deaths caused by the J&J/Janssen Covid-19 vaccination.
CDC officials are still strongly recommending seniors come for their vaccines, which have been shown to give high protection against severe Covid.
According to CDC data, 39 percent of elderly Americans over 65 have received either Pfizer’s or Moderna’s bivalent booster.
Pfizer told DailyMail.com is has been made aware of limited reports of ischemic strokes in people 65 and older following vaccination with their updated shot.
‘Neither Pfizer and BioNTech nor the CDC or the FDA have observed similar findings across numerous other monitoring systems in the US,’ Pfizer added.
‘Globally and there is no evidence to conclude that ischemic stroke is associated with the use of the companies’ Covid-19 vaccines.
‘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.’
Pfizer/BioNtech and Moderna’s bivalent shots, which target both the original coronavirus and Omicron sub-variants, have been authorized for use in children six months and older.
The shots were brought into the fold because they directly target the Omicron variant.
Original Covid vaccines that rolled out in late 2020 were tailored towards the Wuhan strain of the virus, which emerged at the start of that year.
The Omicron variant, which took over the world at the end of 2021, mutated to bypass protection from those shots, though.
These bivalent shots are meant to bolster protection against infection and slow the spread of the many emerging forms of Omicron.
An ischemic stroke, also known as brain ischemia, occurs when the flow of blood to the brain is interrupted. This is usually from a blood clot.
Brain tissue begins to die within minutes of it being deprived of oxygen-rich blood.
More than 700,000 Americans suffer an ischemic stroke each year. It accounts for almost 90 percent of all strokes.
A stroke is fatal in up to 20 percent of cases. Even survivors are often left with permanent brain damage, which leads to speech, vision and mobility issues – among other things.
Early last year, the CDC warned that young males who had received the mRNA vaccines – either the Pfizer or Moderna shot were at an increased risk of suffering heart inflammation.
The agency warned that myocarditis was appearing more frequently in males 16 and older within seven days of receiving the shot.
In previous investigations of possible risks of myocarditis, health officials found stronger signals as they went through other safety databases, but the ischemic stroke link has so far not been held up.
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Read more at DailyMail.co.uk