Bell's palsy, an asymmetrical paralysis of the face that is often temporary, is one adverse effect of COVID-19 vaccine clinical trials. It has been reported that Bell's palsy is a rare side-effect of the vaccine.
However, a new study shows that it is seven times more common on COVID-19 patients than those who are vaccinated. Studies suggest that out of 37,000 vaccine recipients, only eight cases of Bell's palsy were reported, Daily Mail reported. In which for every 100,000 vaccine recipients, there are 19 cases of Bell's palsy compared to an incidence of 82 per 100,000 for COVID-19 patients.
Researchers said that more studies are needed to carefully monitor the side effects of the vaccine. They noted that Bell's palsy should be another reason for the public to get vaccinated and should not see it as a side-effect.
Incidence of Bell's Palsy After Vaccination
The website called Drug Discovery and Development reported that two vaccine recipients during the phase 3 clinical trial of Johnson & Johnson developed Bell's palsy, while two people as well have developed the condition in the placebo group.
Moreover, a patient also showed signs of facial swelling and droopiness without facial asymmetry, but clinical trial investigators concluded that this case was not due to the vaccines administered.
Meanwhile, during the phase 3 clinical trial of Modern, three vaccine recipients also developed Bell's palsy and one in the placebo group as well. In Pfizer-BioNTech's clinical trial, four vaccine recipients developed the condition, while no one in the placebo group did.
All three phase 3 clinical trials involved 30,000 to 40,000 patients. Due to the numerical imbalance between the rate in vaccine and placebo groups in Pfizer's and Moderna's clinical trial, the FDA and CDC decided to monitor vaccine recipients to see if they are going to develop Bell's palsy.
But the FDA has not concluded yet whether those vaccines could have caused the condition. On the other hand, CDC recommends further studies to be conducted to gather more data before doing an assessment on any possible causal association between the vaccine and the condition.
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Bell's Palsy More Common in COVID-19 Patients than Vaccinated People
Bell's palsy is a condition of sudden muscle weakness or paralysis that causes the other half of the face to droop, leading to one-sided smiles and one eye that refuses to close. The exact causes of the condition are unknown but according to Johns Hopkins, it may be associated with diabetes, high blood pressure, injury, Lyme disease, and some infections.
The study, entitled "Incidence of Bell Palsy in Patients With COVID-19" published in JAMA Otolaryngology-Head & Neck Surgery, showed that COVID-19 patients have a 0.08% risk of developing Bell's palsy.
Two clinical trials of Pfizer and Moderna vaccines showed that only eight cases of Bell's palsy were reported out of 37,000 vaccine recipients, Daily Mail reported This translates to 19 Bell's palsy cases for every 100,000 vaccinations, or 0.02% risk.
Matching the data to 64,000 non-vaccinated COVID-19 patients, they found that these patients are almost seven times more likely to develop Bell's palsy than those vaccinated people.
The findings support FDA's statement that there is no clear association between the vaccines and developing Bell's palsy. But it also noted that Pfizer and Moderna vaccines may have a higher Bell's palsy risk compared to other vaccines that are not using the mRNA technology.
Scientists are unsure yet of what may have triggered Bell's palsy in COVID-19 patients but some believe that the virus could have triggered an interaction between the immune system and the nervous system. Ultimately, more research is needed for careful monitoring to determine how the infection could cause Bell's palsy.
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