Bell’s palsy has been reported as a rare side effect of COVID-19 vaccines, but it is actually more common in those who get sick with the disease, a new study finds.
Researchers at University Hospitals Cleveland Medical Center and Case Western Reserve University School of Medicine found that coronavirus patients were seven times more likely to have the facial paralysis compared to those who had been vaccinated against the illness.
Out of 37,000 vaccine recipients, only eight cases of Bell’s palsy were reported – an incidence of 19 cases for every 100,000 vaccine recipients, compared to an incidence of 82 per 100,000 for Covid patients.
While doctors and vaccine manufacturers will continue to carefully monitor vaccine side effects, the team says the findings indicate that Bell’s palsy should be an additional reason to get vaccinated – not a side effect to fear.
Bell’s palsy is a nerve condition impacting one half of a patient’s face
The condition has been linked to Covid – patients have a 0.08 percent risk of developing it
Bell’s palsy is a condition that unexpectedly strikes a patient’s face.
The patient experiences sudden muscle weakness or paralysis that causes half of their face to appear to droop. This leads to one-sided smiles and one eye that refuses to close.
It is usually a temporary condition with symptoms typically improving within a few weeks, with complete recovery in six months.
A small number of patients will have some symptoms for a longer time, or will see a resurgence of the condition later in life.
While exact causes for the condition are unknown, scientists hypothesize that it’s caused by an overreaction of the body’s immune system, which leads to inflammation, or swelling, that damages a nerve controlling facial movement.
Bell’s palsy may be associated with diabetes, high blood pressure, injury, Lyme disease, and some infections, according to Johns Hopkins.
The condition impacts relatively few people each year with the U.S. seeing an estimated 15 to 30 cases for every 100,000 people.
Recently, however, the condition has drawn more attention as a small number of Bell’s palsy cases have been reported in patients who received Covid vaccines.
But Bell’s palsy is actually more likely to occur in patients infected with the coronavirus itself than in those who get vaccinated, new research suggests.
For the study, published on Thursday in JAMA Otolaryngology – Head & Neck Surgery – the team investigated Bell’s palsy risk using anonymous, electronic medical records from 41 healthcare organizations around the world.
In those records, the doctors looked for patients diagnosed with Covid between January and December 2020 – then identified those who were also diagnosed with Bell’s palsy within eight weeks of their Covid infection.
Overall, the doctors identified 284 Bell’s palsy cases among the Covid patients – out of about 348,000 patients in total. This indicates that Covid patients have a 0.08 percent risk of Bell’s palsy.
Among those 284 patients, slightly over half (54 percent) had no history of Bell’s palsy prior to getting the coronavirus. The other 46 percent did have a history with the condition.
While a small number of Bell’s palsy cases have been reported after Covid vaccination, the risk of this condition is higher for those who are infected with the virus itself
The doctors compared the Bell’s palsy risk for Covid patients to the risk for those who receive Covid vaccines.
In two trials of the Pfizer and Moderna vaccines – including a total 74,000 patients, 37,000 of whom received vaccines – just eight Bell’s palsy cases were reported. Seven of those cases occurred among the vaccinated patients.
This translates to an incidence of 19 Bell’s palsy cases for every 100,000 vaccinations, or a 0.02 percent risk.
In order to more directly compare the Bell’s palsy risk between Covid patients and vaccine recipients, the researchers matched 64,000 non-vaccinated Covid patients to those who received vaccines.
The matching showed that Covid patients were 6.8 times more likely to develop Bell’s palsy compared to those who received vaccines.
This new study backs up past evidence cited by the Food and Drug Administration (FDA), which says there is no significant association between the Covid vaccines and Bell’s palsy.
Still, some scientists have argued that the Pfizer and Moderna vaccines may have higher Bell’s palsy risk than other vaccines that do not use mRNA.
Scientists don’t yet know how Covid – or a Covid vaccine – may cause Bell’s palsy.
One hypothesis suggests that the virus could trigger an interaction between the immune system and the nervous system, similarly to other viruses that have been linked to the condition.
More research and careful monitoring is needed to determine how Covid causes Bell’s palsy and if any significant risk exists for vaccines.
The current research suggests, however, that patients can get vaccinated against Covid without worrying about this highly rare condition.