​​Does Sinovac’s CoronaVac Increase the Risk of Bell’s Palsy After Immunization?

First-time recipients of Sinovac’s COVID-19 vaccine (CoronaVac) face an increased risk of developing Bell’s palsy, a sudden and temporary facial paralysis, according to a study published in The Lancet Infectious Diseases journal.

The authors of the study advise that the protective effects of the vaccine far outweigh the risks. 

Association Between COVID-19 Vaccines and Bell’s Palsy

Cases of Bell’s palsy have been reported at higher rates in the clinical trials of Moderna’s and Pfizer/BioNTech’s mRNA vaccines, compared to what is expected in the general population. The rate of the adverse event occurring after immunization with inactivated COVID-19 vaccines, such as the Sinovac-developed CoronaVac, has not been published until a few days ago.

A recent study conducted in Hong Kong compared the rates of the adverse event within 42 days after immunization with either CoronaVac or Pfizer-BioNTech’s vaccine.

Of over 451,000 individuals who received the first shot of CoronaVac, 28 developed Bell’s palsy, compared to 16 out of over 537,000 individuals who received Pfizer’s shot.  Further analysis showed that nearly five more people out of 100,000 would develop the condition after the CoronaVac shot compared to natural occurrence in the general population. These results suggested a significantly higher risk of developing Bell’s palsy after CoronaVac vaccination, but not for Pfizer-BioNTech’s vaccine.

Vaccination Benefits Still Outweigh Risk

Bell’s palsy, also known as acute peripheral facial nerve palsy of unknown cause, is a sudden onset of facial paralysis that usually affects one side of the face or head. The effects are often temporary — with the right corticosteroid treatment, the vast majority (over 90%) of patients make a full recovery after 9 months.

“The beneficial and protective effects of the inactivated COVID-19 vaccines far outweigh the risk of this generally self-limiting adverse event,” the authors of the study affirmed, echoing the stance of many in the field.

Author

Joy Lin

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