This rare side effect of Covid-19 vaccination causes one-sided facial paralysis

While developing Bell's palsy after a Covid-19 shot might be frightening, it is only a temporary side effect and will resolve on its own. — Photos: AFP

I read about some Covid-19 vaccines giving rise to this rare side effect called Bell’s palsy. I am a little worried. Should I be concerned about this side effect?

Not at all, the risk of getting a serious Covid-19 vaccination side effect is far, far lower than the actual risk of getting Covid-19 itself, not to mention the risk of getting severe complications from Covid-19, including dying.

So you should absolutely go for vaccination.

Any Covid-19 vaccine is better than no vaccine at all.

So what is this I am reading about the possible side effect of Bell’s palsy with certain Covid-19 vaccines?

This is a recent paper from the esteemed medical journal, The Lancet.

There was a study conducted among 451,000 people in Hong Kong.

Among these 451,000 people, there were 28 cases of Bell’s palsy after their first dose of CoronaVac (more popularly known as the Sinovac vaccine) and 14 cases after the first dose of the Pfizer/BioNTech vaccine.

This is a drop in the ocean compared to the number of people who have already received and completed both vaccines.

In addition, the Bell’s palsy reversed itself – meaning that it was only a temporary side effect – and the patients were completely all right after that.

The researchers concluded that: “Our findings suggest an overall increased risk of Bell’s palsy after CoronaVac vaccination.

“However, the beneficial and protective effects of the inactivated Covid-19 vaccine far outweigh the risk of this generally self-limiting adverse event.”

What is Bell’s palsy?

Bell’s palsy is a condition where the muscles of the face are paralysed.

It is also known as acute peripheral facial palsy of unknown cause, as no one has figured out the reason behind it yet.

Some scientists have a hypothesis that it is the result of inflammation, which causes swelling of the facial nerve that controls the muscles of the face.

This inflammation may be caused by a virus.

People often notice that their Bell’s palsy began after a viral infection.

Viruses that have been known to be present before the onset of Bell’s Palsy include those causing:

• Flu (influenza B viruses)
• Chicken pox (Varicella zoster)
• Shingles (Herpes zoster)
• Cold sores and genital herpes (Herpes simplex virus)
• Infectious mononucleosis (Epstein-Barr virus)
• Cytomegalovirus infections
• German measles (Rubella virus)
• Mumps (Mumps virus)

Actor Sylvester Stallone’s signature slurred speech and lopsided grin is attributed to residual effects from Bell’s palsy caused by complications during his birth.

How would I know if I have Bell’s palsy? Is it painful?

There is usually no pain at all, or very little pain, if it occurs.

Bell’s palsy usually affects one side of your face only, meaning only one facial nerve.

Only very few people have Bell’s palsy on both sides of their face.

It is a temporary condition for most people, lasting a few weeks to six months.

Only very few people continue to have some residual symptoms for life.

I had a version of it once upon a time, when I went for surgery to remove my parotid gland.

The facial nerve on the side of my face that was operated on was “twinged’, and therefore “stimulated”.

It recovered on its own within two months.

Bell’s palsy can come on very suddenly – almost without warning – occurring within hours or days.

You may have mild, moderate or severe (total) paralysis of one side of your face.

You will notice in the mirror that one side of your face droops.

You may not be able to close your eye fully, or even smile on one side.

You may even drool from the affected side.

Some people experience pain around the jaw or behind the ear.

You may get a headache and increased sensitivity to sound on the affected side.

You may also have loss of taste on one side of your tongue, and less tears and saliva on the affected side.

Are there certain types of people more at risk of getting Bell’s palsy?

Yes. Pregnant women are more at risk, especially when they are in their last three months of pregnancy or around one week after they have given birth.

You are certainly more at risk after you have had a viral infection like a cold or the flu.

Diabetic patients are also at higher risk of getting it.

Some people have found a family linkage.

If your parents have had Bell’s palsy before, you are more likely to have it than people whose parents have never had it before.

Is there any treatment for it?

Most people recover fully from Bell’s palsy without any treatment.

Some doctors may give you steroids to reduce the inflammation and ask you to go for physiotherapy of the face.

In physiotherapy, you will be asked to exercise your facial muscles, and the physiotherapist will stimulate your nerve so that it will work again.

You have to protect your eye if it cannot close by wearing wearing an eye patch at night when you sleep.

You will usually be able to chew normally though.

Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health, computers and entertainment. For further information, email [e-mail]. The information contained in this column is for general educational purposes only. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.