AstraZeneca’s COVID-19 vaccine trails remain on hold in the United States, despite resuming in countries such as the United Kingdom, India, and Brazil.
Experts have voiced concerns about AstraZeneca’s vaccine trials after the company confirmed two UK volunteers suffered serious neurological illnesses.
Because of the illnesses, the study was paused twice, the second time earlier this month.
AstraZeneca said the first participant received one dose of the vaccine before developing inflammation of the spinal cord, known as transverse myelitis.
The condition is a rare inflammatory disease causing injury to the spinal cord with varying degrees of weakness, sensory alterations, and autonomic dysfunction, according to the National Organisation for Rare Disorders.
AstraZeneca said it had not confirmed a diagnosis in the second case, a participant who got sick after the second dose of the vaccine.
But a person familiar with the situation told The Times the participant’s illness had been pinpointed as transverse myelitis too.
“If there are two cases, then this starts to look like a dangerous pattern,” said Mark Slifka, a vaccine expert at Oregon Health and Science University.
“If a third case of neurological disease pops up in the vaccine group, then this vaccine may be done.”