COVID-19, Flu Vaccines Taken Together Linked to Stroke Risk
A growing number of studies indicate that receiving COVID-19 and influenza vaccines at the same time increases the risk of stroke, though other studies have not found an increased risk.
The Food and Drug Administration (FDA) recently announced that some elderly people who received the Moderna or Pfizer vaccines concurrently with a high-dose/adjuvanted influenza vaccine had an increased risk of stroke.
Researchers from Kaiser Permanente discovered an increased risk for people under 65 who received the Pfizer-BioNTech COVID-19 vaccine and a flu shot on the same day.
The FDA and the Centers for Disease Control and Prevention (CDC) previously discovered a link between Pfizer’s bivalent vaccine and ischemic stroke, a type of stroke caused by blood clotting, authorities said in January. And, according to documents obtained by The Epoch Times, the CDC detected a link between the original Moderna and Pfizer vaccines and ischemic stroke in adults in 2022.
The link between the vaccines and stroke is not yet proven, according to authorities, but some experts say the papers support the position of spacing out shots to reduce the risk of side effects.
“That’s a reasonable thing to do,” said Dr. William Schaffner, a vaccine expert who advises the CDC.
Dr. Peter Marks, a top FDA official, stated at a recent conference that the influenza, COVID-19, and respiratory syncytial virus vaccines would be spaced out to reduce the risk of adverse events.
“Oftentimes, we suggest if you want to minimize the chance of interactions and minimize confusing side effects from one with another, you wait about two weeks between the vaccines,” he went on to say.
Another recent study found that when adults received Pfizer’s vaccine and a seasonal inactivated influenza vaccine together, they experienced more adverse events than when they received either vaccine alone.
Dr. David Boulware, an infectious disease expert at the University of Minnesota Medical School, told The Epoch Times in an email that he generally recommends getting the COVID-19 and influenza vaccines at different times “so that one vaccine does not blunt the response of the other.”
One study, for example, discovered that coadministering vaccines resulted in lower levels of antibodies, which are thought to protect against illnesses.
“If I’m going to get a vaccine, I’d like to get the full benefit,” Dr. Boulware said.
Uncertainty
Other studies, including one in England that looked at simultaneous COVID-19 vaccination and influenza vaccination, found no link between the COVID-19 vaccines and stroke. The COVID-19 vaccines examined in the study were never used in the United States.
“Available data do not provide clear and consistent evidence of a safety problem for ischemic stroke with bivalent mRNA COVID-19 vaccines when given alone, given simultaneously with influenza vaccines, or when influenza vaccine is given alone,” Dr. Tom Shimabukuro, a CDC vaccine safety official, told a panel of the agency’s advisers on Oct. 25 as he reviewed papers from the FDA, Kaiser Permanente, and England.
Dr. Shimabukuro also repeated the CDC-refused lie that the agency never detected an ischemic stroke signal for the original vaccines.
The researchers who discovered the elevated risk say more research is needed to validate the signals.
“The potential association between bivalent COVID-19 vaccination and ischemic stroke…. warrants further investigation among individuals,” Kaiser Permanente researchers wrote in a preprint paper.
The self-controlled case series only looked at strokes among vaccinated people. The researchers compared the incidence of stroke in the first 42 days following vaccination to the incidence in the same people after that time.
They discovered 373 strokes within 42 days of receiving bivalent vaccination and 1,511 strokes after 42 days.
People under the age of 65 who received a Pfizer or Moderna vaccine, had a history of COVID-19, and received an influenza vaccine at the same time had an increased risk.
People in the same age group who received Pfizer’s shot with an influenza shot and did not have a history of COVID-19 and people who received Moderna’s shot, had a history of COVID-19, and did not receive an influenza vaccine concurrently had an increased risk.
The FDA researchers also conducted a self-controlled case series among Medicare beneficiaries who were not immunized. They used risk intervals within 42 days of vaccination and control intervals between 43 and 90 days.
Researchers discovered an increased risk of non-hemorrhagic stroke and non-hemorrhagic stroke/transient ischemic attack in Pfizer recipients aged 85 and older, as well as non-hemorrhagic stroke/transient ischemic attack in Moderna recipients aged 65 to 74.
There was also an increased risk of non-hemorrhagic stroke among all 65-year-old recipients 22 to 42 days after concomitant high-dose/adjuvanted influenza and Pfizer vaccination, as well as an increased risk of transient ischemic attack one to 21 days after concomitant high-dose/adjuvanted influenza and Moderna vaccination.
Dr. Boulware, who was not involved in the study, expressed interest in seeing the findings replicated by other researchers.
According to the FDA researchers, their study did not change the agency’s position that the benefits of the COVID-19 outweigh the risks in the elderly, but it did indicate a “need for additional investigations” into the safety of high-dose/adjuvanted influenza vaccines. The Australian researchers stated that their study supported the use of Pfizer’s vaccine in conjunction with an influenza vaccine.
