A connection between a significant increase in cases of the serious neurological condition known as Guillain-Barre Syndrome (GBS) and first dose of the AstraZeneca Covid Jab has been identified.
According to researchers at the University College London (UCL), the small numbers of GBS cases observed appear similar to increases seen previously in other mass vaccination campaigns.
Guillain-Barre Syndrome, a rare but serious autoimmune condition attacks the peripheral nervous system which usually results in numbness, weakness, and pain in the limbs. It also sometimes results in paralysis of breathing. It often occurs after infections, particularly gastroenteritis infection called Campylobacter, with the immune system mistakenly attacking nerves in the body instead of germs.
The syndrome is usually reversable, but in severe cases prolonged paralysis involving breathing muscles that requires ventilator support occurs, and at times it can leave permanent neurological deficits which can be caused by the condition. The key to proper treatment is early diagnosis.
In December 2020 in the UK, Pfizer’s Covid 19 vaccine (tozinameran) was rolled out, which was followed a month later by a roll out of AstraZeneca (ChAdOx1 nCoV-19), then Moderna (mRNA-1273) three months after that.
The study was published in the journal Brain.
Researchers observed that between January 2021 and October 2021, 996 GBS cases were recorded in the UK National Immunoglobulin Database. There was an unusual spike in the GBS reported cases occurring between March and April of 2021.The study was a population based study of NHS data in England.
Historically, rates of about 100 per month are recorded. But during the months of March and April of 2021, there was approximately 140 cases recorded.
It was revealed during an analysis of the data, that 20 per cent of the 966 cases occurred within six weeks of the first dose of Covid 19 vaccine in England, which equates to 0.618 cases per 100,000 vaccinations.
Of these cases, 176 people had received an AstraZeneca jab, 21 people had received a Pfizer jab, and 1 person had received a dose of Moderna. 23 GBS cases were reported within six weeks of any second dose.
There were 5.8 excess GBS cases per million doses post first dose of AstraZeneca. This equates to an absolute total excess between January-July 2021 of between 98 – 140 cases. First doses of Pfizer and Moderna and second doses of any Vaccine showed no excess GBS risk.
Lead author professor Michael Lunn at UCL Queen Square Institute of Neurology made comments,
“The reason for the association between only AstraZeneca vaccination and GBS is unclear. Covid 19 infection does not have a strong, or possibly any, increased risk of GBS.”
“The lack of increased risk associated with Pfizer vaccination implies that it is unlikely that the Covid 19 spike protein is the causative factor for the increased risk.”
“The viral vector used to carry the nucleic acid in the AstraZeneca and similar vaccines may be the reason, but this needs further exploration.”
“Higher numbers of cases of GBS are seen in the period of two to four weeks after vaccination. A peak of cases observed around 24 days following a first dose.”
“First doses of AstraZeneca vaccine account for the majority or all of this increase. A similar pattern is not seen with the other vaccines or following a second dose of any vaccine.”
A separate study was done, and researchers analysed GBS cases that had been reported by clinicians between January 2021 and November 2021. The found that no specific clinical features, including facial weakness (which has received special attention in medical literature), were associated with vaccination-related GBS as compared to non-vaccinated cases. This demonstrated the difficulties in finding the vaccination linked cases among the background cases that were normally occurring. This study was UK-wide (four nations) hospitals’ surveillance data where they observed phenotypes (characteristics/symptoms). The aim was to identify if there were any specific features of Covid 19 vaccine-associated GBS.
For historical context of vaccine-associated GBS, a swine flu vaccination program that was carried out in the US in 1976. There was a small increase of GBS cases associated with what was considered a novel flu jab at that time. The vaccination program was halted because there was a statistical increase in developing GBS. However, a subsequent statistical analysis was carried out and found that the risk of a link was lower than originally believed.
Among his comments, Professor Lunn said, “Adenoviruses have not been strongly associated with GBS in previous studies, and any association between adenoviral vaccination and GBS has only once been reported. Nevertheless, adenovirus testing is not routinely performed in cases of GBS in the UK, and whether adenoviruses may account for a proportion of ‘idiopathic’ (no known cause) or ‘SARS-CoV-2 negative’ GBS may be the subject for further study.”