According to Prof Spector, 85 percent of users reporting metallic taste and one local side effect, such as a bruised arm, also reported one systemic side effect, such as fatigue after injection.
While this may seem high, when the ZOE team compared it to the accounts of any systemic side effect, such as pain in the arm, that was already at 81 percent so “no strong association there”, noted prof Spector.
“But 15 percent of users reporting at least one local side effect and metallic taste reported having five or distinct or systemic side effects in the week after vaccination and that was higher than the 5.8 percent who didn’t have metallic taste,” he said.
This does indicate a large difference in people reporting something soon after injection and some long-term effect but context is important here, the ZOE lead said.