Original
There are surely more triggers for GBS than are known / documented, which is why it is considered a syndrome, rather than a disease which has better known causes. A frequent cause is the body's' response to an inoculation, like a flu shot. Other's like myself are caused by exposure to the campylobacter bug present in raw chicken. Often, the onset is preceded by an upper respiratory infection. Zika virus has been linked to the onset. The trigger agents are too numerous to mention, & the list is ever-growing with time.