Cases of Bell’s palsy and death observed during Pfizer/BioNTech vaccine clinical trials were within expected background range of general population
Simply because one event (A) followed another (B) does not mean that B caused A. In a large enough population, deaths and cases of Bell’s palsy are expected to occur solely by random chance. While a certain number of deaths and cases of Bell’s palsy were observed during the clinical trials of the Pfizer/BioNTech COVID-19 vaccine, the frequency of these events wasn’t higher than the expected background rate for the general population. This does not indicate a causal relationship between the events and the vaccine.
Inadequate support: Even in an unvaccinated population, a certain number of deaths and cases of Bell’s palsy are expected solely by random chance. The frequency of death and Bell’s palsy seen in vaccine participants is not higher than the expected background rate, indicating that there is most likely no causal relationship to the vaccine.
Following the publication of the U.S. Food and Drug Administration (FDA) review of the COVID-19 vaccine by Pfizer and BioNTech, social media posts and articles went viral on Facebook, claiming that the vaccine was responsible for causing adverse reactions, such as death and a type of facial paralysis known as Bell’s palsy. Examples can be seen here and here. Many such posts have also shared photos of patients affected by Bell’s palsy, leaving the impression that these patients were the actual participants in the trial. However, these photos existed long before the trial, as can be seen in this article published in June 2020.
To verify the claim that the vaccine is responsible for these adverse effects, Health Feedback examined the FDA Briefing Document for the Pfizer/BioNTech COVID-19 vaccine, a product of the Vaccines and Related Biological Products Advisory Committee meeting on 10 December 2020. The full document can be found here.
With regards to deaths observed during the trials, the Committee noted on page 41 of the document that:
“A total of six (2 vaccine, 4 placebo) of 43,448 enrolled participants (0.01%) died during the reporting period from April 29, 2020 (first participant, first visit) to November 14, 2020 (cutoff date). Both vaccine recipients were >55 years of age; one experienced a cardiac arrest 62 days after vaccination #2 and died 3 days later, and the other died from arteriosclerosis 3 days after vaccination #1. The placebo recipients died from myocardial infarction (n=1), hemorrhagic stroke (n=1) or unknown causes (n=2); three of the four deaths occurred in the older group (>55 years of age). All deaths represent events that occur in the general population of the age groups where they occurred, at a similar rate.” (emphasis added)
In other words, the number of deaths observed in the vaccine group was within the expected range for the general population, accounting for differences due to age.
Bell’s palsy is the result of facial nerve inflammation. According to Facial Paralysis U.K., a charity that provides support to affected patients, “Bell’s palsy is the commonest cause of facial palsy, accounting for approximately 80 per cent of all cases.”
Facial Paralysis U.K. also explains that “no conclusive cause has been established” for Bell’s palsy, and that “A large review showed that just over 70 per cent of people with Bell’s palsy make a full recovery. Improvement can occur as early as two to three weeks from onset; however, a full recovery can take anywhere from three to six months and beyond.”
According to the U.S. National Institutes of Health:
“Most scientists believe that reactivation of an existing (dormant) viral infection may cause the disorder. Impaired immunity from stress, sleep deprivation, physical trauma, minor illness or autoimmune syndromes are suggested as the most likely triggers.”
With respect to the events of Bell’s palsy observed during the trial, the FDA briefing document states on page 43:
“The all-enrolled population contained more participants >16 years of age, regardless of duration of follow-up (43448; 21720 vaccine, 21728 placebo) […]
Bell’s palsy was reported by four vaccine participants. From Dose 1 through 1 month after Dose 2, there were three reports of Bell’s palsy in the vaccine group and none in the placebo group. This observed frequency of reported Bell’s palsy is consistent with the expected background rate in the general population. There were no other notable patterns or numerical imbalances between treatment groups for specific categories of non-serious adverse events (including other neurologic, neuro-inflammatory, and thrombotic events) that would suggest a causal relationship to BNT162b2 vaccine.” (emphasis added)
In short, both deaths and cases of Bell’s palsy observed during the trial occurred at a frequency consistent with that expected in an unvaccinated population. Because the number of participants included in the trial was very large—with more than 20,000 people each in the vaccine and placebo group—a certain number of deaths and Bell’s palsy were expected to occur solely based on the background rate, with or without the vaccine.
Since the frequency of these events was not higher than expected, the evidence so far does not indicate that the vaccine caused these events. Rather, it is likely that these events occurred by chance after the vaccine was administered. However, “it’s very early in the vaccine roll-out to the non-study-trial population,” so more data will still be needed to rule out a causal relationship, as Nina Shapiro, professor of head and neck surgery at the David Geffen School of Medicine at University of California Los Angeles, wrote in this Forbes article. The FDA stated that it would continue to monitor cases of Bell’s palsy in people who had received the vaccine.
A commentary, published in Science Translational Medicine on 4 December 2020, highlighted the problem of misinformation as a result of misattributing any adverse effect following vaccination to the vaccine itself. This is also known as the post hoc ergo propter hoc fallacy:
“We’re talking about treating very, very large populations, which means that you’re going to see the usual run of mortality and morbidity that you see across large samples. Specifically, if you take 10 million people and just wave your hand back and forth over their upper arms, in the next two months you would expect to see about 4,000 heart attacks. About 4,000 strokes. Over 9,000 new diagnoses of cancer. And about 14,000 of that ten million will die, out of usual all-causes mortality. No one would notice. That’s how many people die and get sick anyway.
But if you took those ten million people and gave them a new vaccine instead, there’s a real danger that those heart attacks, cancer diagnoses, and deaths will be attributed to the vaccine. I mean, if you reach a large enough population, you are literally going to have cases where someone gets the vaccine and drops dead the next day (just as they would have if they *didn’t* get the vaccine). It could prove difficult to convince that person’s friends and relatives of that lack of connection, though. Post hoc ergo propter hoc is one of the most powerful fallacies of human logic, and we’re not going to get rid of it any time soon.”
13/ 3rd concern: misinformation. Below: if we vaccinate 10M Americans, how many will develop a serious illness in 2 months after they got their shots. Answer: many thousands (& I’ve only included 4 illnesses, plus death).
And the vaccines will have zero to do with any of them. pic.twitter.com/MvuXCI0MHG
— Bob Wachter (@Bob_Wachter) December 2, 2020