Research, published in the BMJ, found no evidence that COVID-19 vaccines cause immune-mediated neurological disorders such as Bell's palsy (facial weakness), encephalomyelitis (inflammation of the brain and spinal cord), and Guillain-Barré syndrome (a nerve condition). But rates for these conditions were higher than otherwise expected for unvaccinated people infected with SARS-CoV-2.
The COVID-19 pandemic has caused more than 5.5 million deaths worldwide and rising. But a global research effort led to new vaccines being developed and approved, and to date over 9 billion doses have been administered worldwide.