- BBC News World
Following fears about the risks that some of the covid-19 vaccines cause clots, a new adverse effect registered in a small number of vaccinated people is causing concern in different parts of the world.
It is an unusual neurological disease known as Guillain-Barré syndrome (GBS), an autoimmune disorder that affects the nervous system and generates progressive paralysis of muscles.
At the end of July, the National Health Surveillance Agency of Brazil (Anvisa) issued a warning after the appearance of 34 suspected cases of GBS in people who had been inoculated against the coronavirus.
Twenty-seven had received the AstraZeneca vaccine, four from CoronaVac and three from Janssen.
On July 9, the European Medicines Agency (EMA) had warned of a possible link between AstraZeneca vaccine and GBS.
The regulator said that for the moment “neither confirms nor discards” that relationship, but recommended making a change in the information on the vaccine to include a warning that alerts you to the signs and symptoms that may occur, for early diagnosis and treatment.
A few days later, the United States Food and Drug Administration (FDA) updated the information on the Janssen vaccine, produced by Johnson & Johnson, to warn of a slight increase in the risk of getting GBS.
“Reports of adverse events after use of the Janssen covid-19 vaccine under emergency use authorization suggest an increased risk of Guillain-Barré syndrome during the 42 days after vaccination,” the updated label reads.
“These cases have been reported mostly about two weeks after vaccination and mostly in males, many of them 50 years or older,” said a spokesman for the US Centers for Disease Control and Prevention. . (CDC) to the US network CNN.
Very few cases
All health agencies have highlighted that the link between this disorder and covid vaccines is still being studied, and that the affected people represent a very small number of the millions who have received these vaccines around the world.
The EMA alert came after 227 suspected GBS cases were reported among the nearly 51.4 million Europeans vaccinated with doses of AstraZeneca as of June 20.
In the case of the Janssen vaccine, the warning was included after 100 suspected cases of GBS were detected among the more than 12 million Americans vaccinated with that single-dose inoculation as of June 30.
In a statement released on July 26, the World Health Organization (WHO) Global Advisory Committee on Vaccine Safety noted that “unusual cases of GBS” were reported in relation to vaccines using an “adenovirus vector”.
“There have been no major reports of GBS after mRNA vaccines,” they said, referring to the method that vaccines like Pfizer and Moderna use.
“More rigorous studies using alternative data sources and robust study designs, and comparison of vaccinated and unvaccinated populations, would be needed to fully assess the significance of these events,” they added.
“Overall, the subcommittee concludes that the potential benefits of Janssen and AstraZeneca’s covid-19 vaccines continue overcoming any potential risk of GBS, particularly given the increase in the more transmissible Delta variant, “they advised.
But what is this rare disease that has also been linked to the influenza (flu) vaccine and the Zika virus?
It’s about a autoimmune neurological disorder uncommon (with one or two cases per 100,000 people, per year) in which the immune system damages nerve cells.
Its cause is unknown, and its effects are usually temporary: most people eventually they fully recover of the disorder.
The syndrome is named after French neurologists Georges Guillain and Jean Alexandre Barré, the first to describe the disease, along with André Strohl, in 1916.
Around 7.5% of people who develop the disease die as a consequence, worldwide.
“The main risk generated by the syndrome is when the respiratory muscles are affected. In the latter case, GBS can cause death if the appropriate measures are not taken,” Anvisa warned BBC News Brazil.
According to the agency, the initial symptoms of GBS in most patients are numbness or burning sensation in the extremities, first the lower ones (feet and legs) and then the upper ones (hands and arms).
They usually develop in an interval from a few hours to a few weeks.
Another characteristic that is perceived in at least 50% of cases is the presence of neuropathic pain (caused by damage to the nervous system) in the lower back or legs.
The progressive weakness It is the most noticeable sign and usually appears in this order: lower limbs, arms, trunk, head and neck.
Dr. Natalia Maes, from the UK’s National Health Service (NHS) explained to the BBC that GBS is an “immune reaction of the body that can occur after various infections (especially respiratory or gastrointestinal) and various vaccines.”
During the 2016 Zika epidemic in Brazil, when 215,319 cases of the virus were reported, there were 970 hospitalizations for GBS (0.45% of all cases).
What to do?
In case of developing signs and symptoms compatible with GBS after receiving a coronavirus vaccine, Anvisa recommends seek immediate medical attention.
Other suspicious symptoms include having double vision or difficulty moving the eyes, difficulty swallowing, speaking, or chewing.
“They should also be on the lookout for problems with coordination and instability, difficulty walking, tingling in the hands and feet, weakness in the extremities, chest or face, and problems with bladder control and bowel function.” the agency added.
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Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.