Health Canada, the Canadian government’s department responsible for national health policy, earlier this month updated the product information label for Pfizer/BioNTech’s experimental messenger RNA (mRNA) biologic (also known as BNT162b2 or “Comirnaty” vaccine) to reflect reported cases of Bell’s palsy—an immune mediated neurological disorder characterized by temporary muscle weakness or paralysis on one side of the face.1 2 3 4
Health Canada had previously added a Bell’s palsy warning to the label of the Moderna/NIAID’s experimental mRNA-1273 biologic (also known as Spikevax vaccine).5
As of July 30, 2021, Health Canada had received 206 reports of Bell’s palsy after receiving the Comirnaty shot. Additionally, there were 67 reports of Bell’s palsy after getting the Spikevax shot and 37 reports of the condition after getting AstraZeneca/Oxford University’s experimental adenovirus vectored AZD1222 vaccine.2 3
According to Johns Hopkins Medicine, Bell’s palsy results from “damage to the facial nerve (the 7th cranial nerve). Pain and discomfort usually occur on one side of the face or head.” The condition is usually not permanent, but “in rare cases, it does not disappear.” Most people who suffer from Bell’s palsy regain full control of their facial expression, with recovery usually occurring from two weeks to six months after initial symptoms appear.6
An advisory issued by Health Canada listed the following additional symptoms of Bell’s palsy:
… uncoordinated movement of the muscles that control facial expression; loss of feeling in the face; headache; tearing from the eye; drooling; lost sense of taste on the front two-thirds of the tongue; hypersensitivity to sound in one ear; or inability to close an eye on one side of the face.1 4
Cases of Bell’s Palsy Reported During Clinical Trials
In a Dec. 22, 2020 article in The Vaccine Reaction, Barbara Loe Fisher, co-founder and president of the National Vaccine Information Center (NVIC), reported that staff members of the U.S. Food and Drug Administration (FDA) had recommended monitoring people who received Pfizer/BioNTech and Moderna/NIAID shots for Bell’s palsy. Fisher noted that the recommendation had been made after the FDA staff had analyzed clinical trial data for both products used by the manufacturers to apply for an Emergency Use Authorization (EUA) to distribute the products in the U.S. before full licensure.7
During pre-EUA clinical trials for the Pfizer/BioNTech mRNA biologic involving 42,000 participants, there were four reported cases of Bell’s palsy among those who had received the biologic. In pre-EUA trials for the Moderna/NIAID biologic, which included 30,000 participants, there were four reported cases of Bell’s palsy and three of the cases had received the product.7
If you would like to receive an e-mail notice of the most recent articles published in The Vaccine Reaction each week, click here.
Click here to view References:
1 Government of Canada. Health Canada updates Pfizer-BioNTech COVID-19 vaccine label to reflect very rare reports of Bell’s Palsy. Aug. 6, 2021.
2 Great Game India. Canada Adds Bell’s Palsy Warning To Pfizer COVID Vaccine. Aug. 7, 2021.
3 Rabson M. Canada now lists Bell’s Palsy as possible, though very rare, side-effect of Pfizer vaccine. National Post Aug. 6, 2021.
4 Vasquez-Peddie A. Health Canada updates Pfizer vaccine label regarding very rare reports of Bell’s palsy. CTV News Aug. 6, 2021.
5 Fahim M. Health Canada now warns of rare cases of Bell’s Palsy with both Pfizer & Moderna vaccines. MyKemptvilleNow.com Aug. 6, 2021.
6 Johns Hopkins Medicine. Bell’s Palsy.
7 Fisher BL. Over 3,000 “Health Impact Events” After COVID-19 mRNA Vaccinations. The Vaccine Reaction Dec. 22, 2020.