There is a small increased risk of developing two rare neurological disorders in the first weeks after being vaccinated with the AstraZeneca vaccine against Covid-19, and bleeding in the brain after the Pfizer vaccine. But after infection with the coronavirus itself, the risk of this and four other neurological complications is much higher. This is evidenced by an analysis of data from more than 32 million Britons collected on Monday Appeared in the scientific journal nature medicine.
AstraZeneca vaccine is related to the rare but serious Guillain-Barré syndrome (GBS) and facial paralysis (Bell’s palsy). In GBS, nerve cells are damaged by the immune system. This can lead, among other things, to tingling and less muscle strength, and even to temporary complete paralysis. In Bell’s palsy, the facial nerve becomes inflamed and the muscles on one side of the face suddenly become paralyzed. Most patients recover completely from these conditions after a few weeks to months.
Huge amount of data
Rare neurological complications have been reported frequently after vaccination and after infection with SARS-CoV-2. The strength of the UK study lies in the sheer volume of data.
Researchers from Oxford University, among others, combined English national vaccination data for more than 32 million adults with national hospital data. For seven neurological complications, they determined the frequency of these complications after vaccination with AstraZeneca or Pfizer, and after infection with SARS-CoV-2. They counted the two cases mentioned, meningitis or myelitis, acute damage to the protective insulating layer around the nerves, neuromuscular disease, and two types of cerebral hemorrhage.
Higher risk after injury
The risk of developing the rare neurological disorders GBS and Bell’s palsy is very small, but has increased slightly in the month following the first dose of the AstraZeneca vaccine. But in the four weeks after infection with SARS-CoV-2, the risk of contracting these five other conditions and diseases is much higher. The researchers estimated that there were an additional 38 patients with GBS among every ten million people after an AstraZeneca injection. After infection with SARS-CoV-2, there were more: 145 additional cases for every 10 million infections. After infection with SARS-CoV-2, other neuroinflammatory diseases also increased dramatically: an additional 123 patients per 10 million had meningitis or myelitis, and an additional 163 cases per 10 million had neuromuscular disorders.
The researchers repeated the analysis with data from 3 million Scots. There, too, they saw the connection between the first AstraZeneca shot and GBS.
Guillain-Barré syndrome usually occurs after a viral infection, such as the flu, a cold, or diarrhea. There is also a slightly increased risk with some vaccinations against other diseases, such as the US herpes zoster vaccine, and after the influenza vaccine. But as with Covid-19, the risk of developing GBS after the flu itself is higher than after the flu shot. Other neurological disorders examined by the British could also be caused by a viral infection. For example, Bell’s palsy can develop after infection with the chickenpox virus (varicella-zoster virus), which can also cause shingles.
Read also: Three questions about the Janssen vaccine and Guillain-Barré . syndrome
on the radar
Facial paralysis and GBS have already been reported as rare and very rare side effects in the AstraZeneca vaccine package insert. GBS is also a very rare side effect of Janssen. These vaccines are of the same type: they are vector vaccines. It is not yet clear why this disorder occurs with vector vaccines but not with mRNA vaccines (Pfizer and Moderna).
Bell’s palsy and Guillain-Barré syndrome have also been on the radar at the center of Larp’s side effects for some time. “This happens very rarely, so it is noticeable when reports come in,” says Director Agnes Kant. A total of 45 reports were received after each of the four vaccines used in the Netherlands. In proportion to the number of people vaccinated with each vaccine, it has also been reported more often after vaccination with AstraZeneca or Janssen, approximately 1 in 100,000 vaccinated. “Brain hemorrhage is more difficult to report, because it happens more often than not,” Kant says. “To get a good picture of that, these kinds of studies are badly needed.”
A version of this article also appeared in NRC Handelsblad on October 26, 2021
A version of this article also appeared on NRC on the morning of October 26, 2021
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