US regulators on Monday added a new warning to Johnson & Johnson's COVID-19 vaccine about links to a rare and potentially dangerous neurological reaction but said it's not entirely clear the shot caused the problem.
What is Guillain-Barré syndrome?
According to the CDC, Guillain-Barré syndrome is "an uncommon sickness of the nervous system in which a person’s own immune system damages the nerve cells, causing muscle weakness, and sometimes, paralysis."
The WHO states that the syndrome can affect the peripheral nerves that control muscle strength as well as those transmitting feelings of pain, temperature, and touch, which can result in muscle weakness and loss of sensation in the legs and/or arms.
What are the causes?
- According to the CDC, the causes of GBS are not yet fully known but in most cases, GBS is preceded by an infection. This could be a bacterial or viral infection, according to the WHO. GBS may also be triggered by vaccine administration or surgery, it adds.
- According to the National Institute of Neurological Disorders and Stroke in the US's National Institutes of Health, GBS is neither contagious nor hereditary. It is called an autoimmune disease as the damage is caused by the body’s own immune system.
- "Normally the immune system uses antibodies (molecules produced in an immune response) and special white blood cells to protect us by attacking infecting microorganisms (bacteria and viruses). In Guillain-Barré syndrome, however, the immune system mistakenly attacks the healthy nerves," it states.
Does the syndrome affect a particular age group more?
According to the NINDS, GBS is estimated to affect about one in 1,00,000 people each year. According to the WHO, Guillain-Barré is a rare condition. Although it is more common in adults and in males, it can affect people in all age groups. The CDC states that true “clusters” of GBS cases are very unusual.
What are the symptoms?
The WHO lists the following symptoms for the Guillain-Barré syndrome:
- The first symptoms include weakness or tingling sensation, which usually starts in the legs, and can spread to the arms and face.
- For some people, these symptoms can lead to paralysis of the legs, arms, or muscles in the face.
- In 20 to 30 percent of cases, the chest muscles are affected, making it hard to breathe.
- In severe cases, the ability to speak and swallow may become affected. These cases are considered life-threatening, and affected individuals should be treated in intensive-care units.
- Complications can include paralysis of the muscles that control breathing, blood infection, lung clots, or cardiac arrest and even in the best of settings, 3–5 percent of patients suffering from the syndrome die from the complications.
- The NINDS also lists difficulty with eye muscles and vision, co-ordination problems and unsteadiness, pain that can be severe, particularly at night, abnormal heart beat/rate or blood pressure, and problems with digestion and/or bladder control as probably symtpoms. It states that most people seek medical care following weakness on both sides of the body.
- Occasionally symptoms start in the upper body and move down to the legs and feet, the NINDS adds.
The global health body states that the symptoms typically last a few weeks but most people most recover fully from even the most severe case of Guillain-Barré syndrome. While some continue to experience weakness, most recover without long-term, severe neurological complications.
According to the NINDS, the types of GBS include acute inflammatory demyelinating polyneuropathy (AIDP) — the most common type in the US— acute motor axonal neuropathy (AMAN), and acute motor-sensory axonal neuropathy (AMSAN). Miller-Fisher syndrome is a rare, acquired nerve disease and a variant of GBS.
What treatment does it require?
- There is no known cure for GBS but there are treatments that can help improve symptoms of GBS and shorten the recovery time.
- The NINDS states that those with GBS are usually admitted and treated in a hospital’s intensive care unit because of possible complications of muscle weakness, problems that can affect any paralyzed person (such as pneumonia or bed sores) and the need for sophisticated medical equipment.
- The WHO has listed recommendations for treatment and care, which include immunotherapy in the acute phase of the disease, supportive care including monitoring of breathing, heartbeat and blood pressure, and rehabilitation services where muscle weakness continues after the acute phase of the illness.