"This is a very rare complication. We have no idea about its cause, it is uncertain why it [the paralysis] is developing. Facial paralysis itself, without connection to the vaccine shot, results from reasons that we do not know at all. It is also unclear why the paralysis is taking place after the vaccine dose", Eidelman said.
This complication goes away quickly for the majority of people, the doctor added, noting that some individuals, however, struggle with it longer.
"For the overwhelming majority, it [the paralysis] is proceeding rather quickly, but it is possible that there will be extremely rare cases, with it [the complication] staying to some extent: there will be improvements, but not completely", Eidelman said.
The Israeli medic also gave an explanation of how the treatment of facial nerve paralysis was linked to antibody levels after being inoculated.
"As a rule, with such a disease, we give corticosteroids or glucocorticosteroids to patients, and they help. But the problem here is that such a complication going along with the vaccine leads to immunosuppression when these medications are taken, and it makes unclear how much effect on the development of antibodies and for immunity those people [patients] will experience. However, this treatment is usually effective", Eidelman added.
Earlier in the week, Israeli media reported, citing Health Ministry officials, that at least 13 Israelis suffered mild facial paralysis after the first dose of the Pfizer vaccine.
The Israeli government signed a deal with Pfizer and BioNTech this past November for 8 million doses of their vaccine. More than 20 percent of its population of over 9 million have so far received the first vaccine dose since the rollout began. At least two elderly Israelis with chronic underlying conditions died after receiving the vaccine.
The vaccination campaign with the Pfizer/BioNTech shot in Israel kicked off on 20 December. Since the start of the pandemic, Israeli health officials have registered 570,085 cases of the coronavirus, including 4,142 fatalities.