Moderna vaccine
Illustrative image: Vials with a sticker reading, "COVID-19 / Coronavirus vaccine / Injection only" and a medical syringe are seen in front of a displayed Moderna logo in this illustration taken October 31, 2020. Image Credit: Reuters

Dubai: The US Food and Drug Administration released a briefing report this week, analysing the trial results of the Moderna COVID-19 vaccine, and found the drug 'highly effective' in combating the coronavirus infection. However, four instances of Bell's Palsy were found in both Pfizer and Moderna vaccine trial volunteers - all but one of whom received the vaccine.

The Moderna vaccine's proposed dosage is two shots, 100 micrograms (ug) each, administered a month apart in patients aged 18 or older. The vaccine was found to have over 94 per cent efficacy after the second shot.

However, four cases of Bell's Palsy were found among the trial participants- three among the vaccinated group and one in the placebo group. While the report concluded that these instances were not enough to prove any link to the vaccine, the authority called for monitoring for such cases in individuals receiving the vaccine.

Bell's palsy, also known as acute peripheral facial palsy of unknown cause, causes half of your face to droop because of temporary weakness in the facial muscles, according to the Mayo Clinic. The condition usually improves in weeks while complete recovery within six months. There are rare cases of permanent drooping or recurrent Bell's Palsy.

The report added, "There were no other notable patterns or numerical imbalances between treatment groups for specific categories of adverse events (including other neurologic, neuroinflammatory, and thrombotic events) that would suggest a causal relationship to mRNA-1273."

Pfizer report

Interestingly, the FDA's report released on December 10 on the Pfizer vaccine also shows four cases of Bell's Palsy, in this case, all of them were in the vaccinated group. The numerical variance has been deemed inconclusive in this case as well since there is not enough evidence to prove a link or causal relationship.

The Pfizer vaccine has currently been approved for emergency use in the US and the UK and in countries in the MENA region.

The FDA’s Vaccines and Related Biological Products Advisory Committee is set to meet Thursday to review Moderna’s vaccine for emergency use authorisation. For both vaccines, FDA staff have called for monitoring to check for adverse effects including Bell's Palsy.